diff options
| author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
| commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
| tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /Documentation/fujitsu | |
| download | lwn-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz lwn-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip | |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'Documentation/fujitsu')
| -rw-r--r-- | Documentation/fujitsu/frv/README.txt | 51 | ||||
| -rw-r--r-- | Documentation/fujitsu/frv/atomic-ops.txt | 134 | ||||
| -rw-r--r-- | Documentation/fujitsu/frv/booting.txt | 181 | ||||
| -rw-r--r-- | Documentation/fujitsu/frv/clock.txt | 65 | ||||
| -rw-r--r-- | Documentation/fujitsu/frv/configuring.txt | 125 | ||||
| -rw-r--r-- | Documentation/fujitsu/frv/features.txt | 310 | ||||
| -rw-r--r-- | Documentation/fujitsu/frv/gdbinit | 102 | ||||
| -rw-r--r-- | Documentation/fujitsu/frv/gdbstub.txt | 130 | ||||
| -rw-r--r-- | Documentation/fujitsu/frv/mmu-layout.txt | 306 |
9 files changed, 1404 insertions, 0 deletions
diff --git a/Documentation/fujitsu/frv/README.txt b/Documentation/fujitsu/frv/README.txt new file mode 100644 index 000000000000..a984faa968e8 --- /dev/null +++ b/Documentation/fujitsu/frv/README.txt @@ -0,0 +1,51 @@ + ================================ + Fujitsu FR-V LINUX DOCUMENTATION + ================================ + +This directory contains documentation for the Fujitsu FR-V CPU architecture +port of Linux. + +The following documents are available: + + (*) features.txt + + A description of the basic features inherent in this architecture port. + + + (*) configuring.txt + + A summary of the configuration options particular to this architecture. + + + (*) booting.txt + + A description of how to boot the kernel image and a summary of the kernel + command line options. + + + (*) gdbstub.txt + + A description of how to debug the kernel using GDB attached by serial + port, and a summary of the services available. + + + (*) mmu-layout.txt + + A description of the virtual and physical memory layout used in the + MMU linux kernel, and the registers used to support it. + + + (*) gdbinit + + An example .gdbinit file for use with GDB. It includes macros for viewing + MMU state on the FR451. See mmu-layout.txt for more information. + + + (*) clock.txt + + A description of the CPU clock scaling interface. + + + (*) atomic-ops.txt + + A description of how the FR-V kernel's atomic operations work. diff --git a/Documentation/fujitsu/frv/atomic-ops.txt b/Documentation/fujitsu/frv/atomic-ops.txt new file mode 100644 index 000000000000..96638e9b9fe0 --- /dev/null +++ b/Documentation/fujitsu/frv/atomic-ops.txt @@ -0,0 +1,134 @@ + ===================================== + FUJITSU FR-V KERNEL ATOMIC OPERATIONS + ===================================== + +On the FR-V CPUs, there is only one atomic Read-Modify-Write operation: the SWAP/SWAPI +instruction. Unfortunately, this alone can't be used to implement the following operations: + + (*) Atomic add to memory + + (*) Atomic subtract from memory + + (*) Atomic bit modification (set, clear or invert) + + (*) Atomic compare and exchange + +On such CPUs, the standard way of emulating such operations in uniprocessor mode is to disable +interrupts, but on the FR-V CPUs, modifying the PSR takes a lot of clock cycles, and it has to be +done twice. This means the CPU runs for a relatively long time with interrupts disabled, +potentially having a great effect on interrupt latency. + + +============= +NEW ALGORITHM +============= + +To get around this, the following algorithm has been implemented. It operates in a way similar to +the LL/SC instruction pairs supported on a number of platforms. + + (*) The CCCR.CC3 register is reserved within the kernel to act as an atomic modify abort flag. + + (*) In the exception prologues run on kernel->kernel entry, CCCR.CC3 is set to 0 (Undefined + state). + + (*) All atomic operations can then be broken down into the following algorithm: + + (1) Set ICC3.Z to true and set CC3 to True (ORCC/CKEQ/ORCR). + + (2) Load the value currently in the memory to be modified into a register. + + (3) Make changes to the value. + + (4) If CC3 is still True, simultaneously and atomically (by VLIW packing): + + (a) Store the modified value back to memory. + + (b) Set ICC3.Z to false (CORCC on GR29 is sufficient for this - GR29 holds the current + task pointer in the kernel, and so is guaranteed to be non-zero). + + (5) If ICC3.Z is still true, go back to step (1). + +This works in a non-SMP environment because any interrupt or other exception that happens between +steps (1) and (4) will set CC3 to the Undefined, thus aborting the store in (4a), and causing the +condition in ICC3 to remain with the Z flag set, thus causing step (5) to loop back to step (1). + + +This algorithm suffers from two problems: + + (1) The condition CCCR.CC3 is cleared unconditionally by an exception, irrespective of whether or + not any changes were made to the target memory location during that exception. + + (2) The branch from step (5) back to step (1) may have to happen more than once until the store + manages to take place. In theory, this loop could cycle forever because there are too many + interrupts coming in, but it's unlikely. + + +======= +EXAMPLE +======= + +Taking an example from include/asm-frv/atomic.h: + + static inline int atomic_add_return(int i, atomic_t *v) + { + unsigned long val; + + asm("0: \n" + +It starts by setting ICC3.Z to true for later use, and also transforming that into CC3 being in the +True state. + + " orcc gr0,gr0,gr0,icc3 \n" <-- (1) + " ckeq icc3,cc7 \n" <-- (1) + +Then it does the load. Note that the final phase of step (1) is done at the same time as the +load. The VLIW packing ensures they are done simultaneously. The ".p" on the load must not be +removed without swapping the order of these two instructions. + + " ld.p %M0,%1 \n" <-- (2) + " orcr cc7,cc7,cc3 \n" <-- (1) + +Then the proposed modification is generated. Note that the old value can be retained if required +(such as in test_and_set_bit()). + + " add%I2 %1,%2,%1 \n" <-- (3) + +Then it attempts to store the value back, contingent on no exception having cleared CC3 since it +was set to True. + + " cst.p %1,%M0 ,cc3,#1 \n" <-- (4a) + +It simultaneously records the success or failure of the store in ICC3.Z. + + " corcc gr29,gr29,gr0 ,cc3,#1 \n" <-- (4b) + +Such that the branch can then be taken if the operation was aborted. + + " beq icc3,#0,0b \n" <-- (5) + : "+U"(v->counter), "=&r"(val) + : "NPr"(i) + : "memory", "cc7", "cc3", "icc3" + ); + + return val; + } + + +============= +CONFIGURATION +============= + +The atomic ops implementation can be made inline or out-of-line by changing the +CONFIG_FRV_OUTOFLINE_ATOMIC_OPS configuration variable. Making it out-of-line has a number of +advantages: + + - The resulting kernel image may be smaller + - Debugging is easier as atomic ops can just be stepped over and they can be breakpointed + +Keeping it inline also has a number of advantages: + + - The resulting kernel may be Faster + - no out-of-line function calls need to be made + - the compiler doesn't have half its registers clobbered by making a call + +The out-of-line implementations live in arch/frv/lib/atomic-ops.S. diff --git a/Documentation/fujitsu/frv/booting.txt b/Documentation/fujitsu/frv/booting.txt new file mode 100644 index 000000000000..4e229056ef22 --- /dev/null +++ b/Documentation/fujitsu/frv/booting.txt @@ -0,0 +1,181 @@ + ========================= + BOOTING FR-V LINUX KERNEL + ========================= + +====================== +PROVIDING A FILESYSTEM +====================== + +First of all, a root filesystem must be made available. This can be done in +one of two ways: + + (1) NFS Export + + A filesystem should be constructed in a directory on an NFS server that + the target board can reach. This directory should then be NFS exported + such that the target board can read and write into it as root. + + (2) Flash Filesystem (JFFS2 Recommended) + + In this case, the image must be stored or built up on flash before it + can be used. A complete image can be built using the mkfs.jffs2 or + similar program and then downloaded and stored into flash by RedBoot. + + +======================== +LOADING THE KERNEL IMAGE +======================== + +The kernel will need to be loaded into RAM by RedBoot (or by some alternative +boot loader) before it can be run. The kernel image (arch/frv/boot/Image) may +be loaded in one of three ways: + + (1) Load from Flash + + This is the simplest. RedBoot can store an image in the flash (see the + RedBoot documentation) and then load it back into RAM. RedBoot keeps + track of the load address, entry point and size, so the command to do + this is simply: + + fis load linux + + The image is then ready to be executed. + + (2) Load by TFTP + + The following command will download a raw binary kernel image from the + default server (as negotiated by BOOTP) and store it into RAM: + + load -b 0x00100000 -r /tftpboot/image.bin + + The image is then ready to be executed. + + (3) Load by Y-Modem + + The following command will download a raw binary kernel image across the + serial port that RedBoot is currently using: + + load -m ymodem -b 0x00100000 -r zImage + + The serial client (such as minicom) must then be told to transmit the + program by Y-Modem. + + When finished, the image will then be ready to be executed. + + +================== +BOOTING THE KERNEL +================== + +Boot the image with the following RedBoot command: + + exec -c "<CMDLINE>" 0x00100000 + +For example: + + exec -c "console=ttySM0,115200 ip=:::::dhcp root=/dev/mtdblock2 rw" + +This will start the kernel running. Note that if the GDB-stub is compiled in, +then the kernel will immediately wait for GDB to connect over serial before +doing anything else. See the section on kernel debugging with GDB. + +The kernel command line <CMDLINE> tells the kernel where its console is and +how to find its root filesystem. This is made up of the following components, +separated by spaces: + + (*) console=ttyS<x>[,<baud>[<parity>[<bits>[<flow>]]]] + + This specifies that the system console should output through on-chip + serial port <x> (which can be "0" or "1"). + + <baud> is a standard baud rate between 1200 and 115200 (default 9600). + + <parity> is a parity setting of "N", "O", "E", "M" or "S" for None, Odd, + Even, Mark or Space. "None" is the default. + + <stop> is "7" or "8" for the number of bits per character. "8" is the + default. + + <flow> is "r" to use flow control (XCTS on serial port 2 only). The + default is to not use flow control. + + For example: + + console=ttyS0,115200 + + To use the first on-chip serial port at baud rate 115200, no parity, 8 + bits, and no flow control. + + (*) root=/dev/<xxxx> + + This specifies the device upon which the root filesystem resides. For + example: + + /dev/nfs NFS root filesystem + /dev/mtdblock3 Fourth RedBoot partition on the System Flash + + (*) rw + + Start with the root filesystem mounted Read/Write. + + The remaining components are all optional: + + (*) ip=<ip>::::<host>:<iface>:<cfg> + + Configure the network interface. If <cfg> is "off" then <ip> should + specify the IP address for the network device <iface>. <host> provide + the hostname for the device. + + If <cfg> is "bootp" or "dhcp", then all of these parameters will be + discovered by consulting a BOOTP or DHCP server. + + For example, the following might be used: + + ip=192.168.73.12::::frv:eth0:off + + This sets the IP address on the VDK motherboard RTL8029 ethernet chipset + (eth0) to be 192.168.73.12, and sets the board's hostname to be "frv". + + (*) nfsroot=<server>:<dir>[,v<vers>] + + This is mandatory if "root=/dev/nfs" is given as an option. It tells the + kernel the IP address of the NFS server providing its root filesystem, + and the pathname on that server of the filesystem. + + The NFS version to use can also be specified. v2 and v3 are supported by + Linux. + + For example: + + nfsroot=192.168.73.1:/nfsroot-frv + + (*) profile=1 + + Turns on the kernel profiler (accessible through /proc/profile). + + (*) console=gdb0 + + This can be used as an alternative to the "console=ttyS..." listed + above. I tells the kernel to pass the console output to GDB if the + gdbstub is compiled in to the kernel. + + If this is used, then the gdbstub passes the text to GDB, which then + simply dumps it to its standard output. + + (*) mem=<xxx>M + + Normally the kernel will work out how much SDRAM it has by reading the + SDRAM controller registers. That can be overridden with this + option. This allows the kernel to be told that it has <xxx> megabytes of + memory available. + + (*) init=<prog> [<arg> [<arg> [<arg> ...]]] + + This tells the kernel what program to run initially. By default this is + /sbin/init, but /sbin/sash or /bin/sh are common alternatives. + + (*) vdc=... + + This option configures the MB93493 companion chip visual display + driver. Please see Documentation/fujitsu/mb93493/vdc.txt for more + information. diff --git a/Documentation/fujitsu/frv/clock.txt b/Documentation/fujitsu/frv/clock.txt new file mode 100644 index 000000000000..c72d350e177a --- /dev/null +++ b/Documentation/fujitsu/frv/clock.txt @@ -0,0 +1,65 @@ +Clock scaling +------------- + +The kernel supports scaling of CLCK.CMODE, CLCK.CM and CLKC.P0 clock +registers. If built with CONFIG_PM and CONFIG_SYSCTL options enabled, four +extra files will appear in the directory /proc/sys/pm/. Reading these files +will show: + + p0 -- current value of the P0 bit in CLKC register. + cm -- current value of the CM bits in CLKC register. + cmode -- current value of the CMODE bits in CLKC register. + +On all boards, the 'p0' file should also be writable, and either '1' or '0' +can be rewritten, to set or clear the CLKC_P0 bit respectively, hence +controlling whether the resource bus rate clock is halved. + +The 'cm' file should also be available on all boards. '0' can be written to it +to shift the board into High-Speed mode (normal), and '1' can be written to +shift the board into Medium-Speed mode. Selecting Low-Speed mode is not +supported by this interface, even though some CPUs do support it. + +On the boards with FR405 CPU (i.e. CB60 and CB70), the 'cmode' file is also +writable, allowing the CPU core speed (and other clock speeds) to be +controlled from userspace. + + +Determining current and possible settings +----------------------------------------- + +The current state and the available masks can be found in /proc/cpuinfo. For +example, on the CB70: + + # cat /proc/cpuinfo + CPU-Series: fr400 + CPU-Core: fr405, gr0-31, BE, CCCR + CPU: mb93405 + MMU: Prot + FP-Media: fr0-31, Media + System: mb93091-cb70, mb93090-mb00 + PM-Controls: cmode=0xd31f, cm=0x3, p0=0x3, suspend=0x9 + PM-Status: cmode=3, cm=0, p0=0 + Clock-In: 50.00 MHz + Clock-Core: 300.00 MHz + Clock-SDRAM: 100.00 MHz + Clock-CBus: 100.00 MHz + Clock-Res: 50.00 MHz + Clock-Ext: 50.00 MHz + Clock-DSU: 25.00 MHz + BogoMips: 300.00 + +And on the PDK, the PM lines look like the following: + + PM-Controls: cm=0x3, p0=0x3, suspend=0x9 + PM-Status: cmode=9, cm=0, p0=0 + +The PM-Controls line, if present, will indicate which /proc/sys/pm files can +be set to what values. The specification values are bitmasks; so, for example, +"suspend=0x9" indicates that 0 and 3 can be written validly to +/proc/sys/pm/suspend. + +The PM-Controls line will only be present if CONFIG_PM is configured to Y. + +The PM-Status line indicates which clock controls are set to which value. If +the file can be read, then the suspend value must be 0, and so that's not +included. diff --git a/Documentation/fujitsu/frv/configuring.txt b/Documentation/fujitsu/frv/configuring.txt new file mode 100644 index 000000000000..36e76a2336fa --- /dev/null +++ b/Documentation/fujitsu/frv/configuring.txt @@ -0,0 +1,125 @@ + ======================================= + FUJITSU FR-V LINUX KERNEL CONFIGURATION + ======================================= + +===================== +CONFIGURATION OPTIONS +===================== + +The most important setting is in the "MMU support options" tab (the first +presented in the configuration tools available): + + (*) "Kernel Type" + + This options allows selection of normal, MMU-requiring linux, and uClinux + (which doesn't require an MMU and doesn't have inter-process protection). + +There are a number of settings in the "Processor type and features" section of +the kernel configuration that need to be considered. + + (*) "CPU" + + The register and instruction sets at the core of the processor. This can + only be set to "FR40x/45x/55x" at the moment - but this permits usage of + the kernel with MB93091 CB10, CB11, CB30, CB41, CB60, CB70 and CB451 + CPU boards, and with the MB93093 PDK board. + + (*) "System" + + This option allows a choice of basic system. This governs the peripherals + that are expected to be available. + + (*) "Motherboard" + + This specifies the type of motherboard being used, and the peripherals + upon it. Currently only "MB93090-MB00" can be set here. + + (*) "Default cache-write mode" + + This controls the initial data cache write management mode. By default + Write-Through is selected, but Write-Back (Copy-Back) can also be + selected. This can be changed dynamically once the kernel is running (see + features.txt). + +There are some architecture specific configuration options in the "General +Setup" section of the kernel configuration too: + + (*) "Reserve memory uncached for (PCI) DMA" + + This requests that a uClinux kernel set aside some memory in an uncached + window for the use as consistent DMA memory (mainly for PCI). At least a + megabyte will be allocated in this way, possibly more. Any memory so + reserved will not be available for normal allocations. + + (*) "Kernel support for ELF-FDPIC binaries" + + This enables the binary-format driver for the new FDPIC ELF binaries that + this platform normally uses. These binaries are totally relocatable - + their separate sections can relocated independently, allowing them to be + shared on uClinux where possible. This should normally be enabled. + + (*) "Kernel image protection" + + This makes the protection register governing access to the core kernel + image prohibit access by userspace programs. This option is available on + uClinux only. + +There are also a number of settings in the "Kernel Hacking" section of the +kernel configuration especially for debugging a kernel on this +architecture. See the "gdbstub.txt" file for information about those. + + +====================== +DEFAULT CONFIGURATIONS +====================== + +The kernel sources include a number of example default configurations: + + (*) defconfig-mb93091 + + Default configuration for the MB93091-VDK with both CPU board and + MB93090-MB00 motherboard running uClinux. + + + (*) defconfig-mb93091-fb + + Default configuration for the MB93091-VDK with CPU board, + MB93090-MB00 motherboard, and DAV board running uClinux. + Includes framebuffer driver. + + + (*) defconfig-mb93093 + + Default configuration for the MB93093-PDK board running uClinux. + + + (*) defconfig-cb70-standalone + + Default configuration for the MB93091-VDK with only CB70 CPU board + running uClinux. This will use the CB70's DM9000 for network access. + + + (*) defconfig-mmu + + Default configuration for the MB93091-VDK with both CB451 CPU board and + MB93090-MB00 motherboard running MMU linux. + + (*) defconfig-mmu-audio + + Default configuration for the MB93091-VDK with CB451 CPU board, DAV + board, and MB93090-MB00 motherboard running MMU linux. Includes + audio driver. + + (*) defconfig-mmu-fb + + Default configuration for the MB93091-VDK with CB451 CPU board, DAV + board, and MB93090-MB00 motherboard running MMU linux. Includes + framebuffer driver. + + (*) defconfig-mmu-standalone + + Default configuration for the MB93091-VDK with only CB451 CPU board + running MMU linux. + + + diff --git a/Documentation/fujitsu/frv/features.txt b/Documentation/fujitsu/frv/features.txt new file mode 100644 index 000000000000..fa20c0e72833 --- /dev/null +++ b/Documentation/fujitsu/frv/features.txt @@ -0,0 +1,310 @@ + =========================== + FUJITSU FR-V LINUX FEATURES + =========================== + +This kernel port has a number of features of which the user should be aware: + + (*) Linux and uClinux + + The FR-V architecture port supports both normal MMU linux and uClinux out + of the same sources. + + + (*) CPU support + + Support for the FR401, FR403, FR405, FR451 and FR555 CPUs should work with + the same uClinux kernel configuration. + + In normal (MMU) Linux mode, only the FR451 CPU will work as that is the + only one with a suitably featured CPU. + + The kernel is written and compiled with the assumption that only the + bottom 32 GR registers and no FR registers will be used by the kernel + itself, however all extra userspace registers will be saved on context + switch. Note that since most CPUs can't support lazy switching, no attempt + is made to do lazy register saving where that would be possible (FR555 + only currently). + + + (*) Board support + + The board on which the kernel will run can be configured on the "Processor + type and features" configuration tab. + + Set the System to "MB93093-PDK" to boot from the MB93093 (FR403) PDK. + + Set the System to "MB93091-VDK" to boot from the CB11, CB30, CB41, CB60, + CB70 or CB451 VDK boards. Set the Motherboard setting to "MB93090-MB00" to + boot with the standard ATA90590B VDK motherboard, and set it to "None" to + boot without any motherboard. + + + (*) Binary Formats + + The only userspace binary format supported is FDPIC ELF. Normal ELF, FLAT + and AOUT binaries are not supported for this architecture. + + FDPIC ELF supports shared library and program interpreter facilities. + + + (*) Scheduler Speed + + The kernel scheduler runs at 100Hz irrespective of the clock speed on this + architecture. This value is set in asm/param.h (see the HZ macro defined + there). + + + (*) Normal (MMU) Linux Memory Layout. + + See mmu-layout.txt in this directory for a description of the normal linux + memory layout + + See include/asm-frv/mem-layout.h for constants pertaining to the memory + layout. + + See include/asm-frv/mb-regs.h for the constants pertaining to the I/O bus + controller configuration. + + + (*) uClinux Memory Layout + + The memory layout used by the uClinux kernel is as follows: + + 0x00000000 - 0x00000FFF Null pointer catch page + 0x20000000 - 0x200FFFFF CS2# [PDK] FPGA + 0xC0000000 - 0xCFFFFFFF SDRAM + 0xC0000000 Base of Linux kernel image + 0xE0000000 - 0xEFFFFFFF CS2# [VDK] SLBUS/PCI window + 0xF0000000 - 0xF0FFFFFF CS5# MB93493 CSC area (DAV daughter board) + 0xF1000000 - 0xF1FFFFFF CS7# [CB70/CB451] CPU-card PCMCIA port space + 0xFC000000 - 0xFC0FFFFF CS1# [VDK] MB86943 config space + 0xFC100000 - 0xFC1FFFFF CS6# [CB70/CB451] CPU-card DM9000 NIC space + 0xFC100000 - 0xFC1FFFFF CS6# [PDK] AX88796 NIC space + 0xFC200000 - 0xFC2FFFFF CS3# MB93493 CSR area (DAV daughter board) + 0xFD000000 - 0xFDFFFFFF CS4# [CB70/CB451] CPU-card extra flash space + 0xFE000000 - 0xFEFFFFFF Internal CPU peripherals + 0xFF000000 - 0xFF1FFFFF CS0# Flash 1 + 0xFF200000 - 0xFF3FFFFF CS0# Flash 2 + 0xFFC00000 - 0xFFC0001F CS0# [VDK] FPGA + + The kernel reads the size of the SDRAM from the memory bus controller + registers by default. + + The kernel initialisation code (1) adjusts the SDRAM base addresses to + move the SDRAM to desired address, (2) moves the kernel image down to the + bottom of SDRAM, (3) adjusts the bus controller registers to move I/O + windows, and (4) rearranges the protection registers to protect all of + this. + + The reasons for doing this are: (1) the page at address 0 should be + inaccessible so that NULL pointer errors can be caught; and (2) the bottom + three quarters are left unoccupied so that an FR-V CPU with an MMU can use + it for virtual userspace mappings. + + See include/asm-frv/mem-layout.h for constants pertaining to the memory + layout. + + See include/asm-frv/mb-regs.h for the constants pertaining to the I/O bus + controller configuration. + + + (*) uClinux Memory Protection + + A DAMPR register is used to cover the entire region used for I/O + (0xE0000000 - 0xFFFFFFFF). This permits the kernel to make uncached + accesses to this region. Userspace is not permitted to access it. + + The DAMPR/IAMPR protection registers not in use for any other purpose are + tiled over the top of the SDRAM such that: + + (1) The core kernel image is covered by as small a tile as possible + granting only the kernel access to the underlying data, whilst + making sure no SDRAM is actually made unavailable by this approach. + + (2) All other tiles are arranged to permit userspace access to the rest + of the SDRAM. + + Barring point (1), there is nothing to protect kernel data against + userspace damage - but this is uClinux. + + + (*) Exceptions and Fixups + + Since the FR40x and FR55x CPUs that do not have full MMUs generate + imprecise data error exceptions, there are currently no automatic fixup + services available in uClinux. This includes misaligned memory access + fixups. + + Userspace EFAULT errors can be trapped by issuing a MEMBAR instruction and + forcing the fault to happen there. + + On the FR451, however, data exceptions are mostly precise, and so + exception fixup handling is implemented as normal. + + + (*) Userspace Breakpoints + + The ptrace() system call supports the following userspace debugging + features: + + (1) Hardware assisted single step. + + (2) Breakpoint via the FR-V "BREAK" instruction. + + (3) Breakpoint via the FR-V "TIRA GR0, #1" instruction. + + (4) Syscall entry/exit trap. + + Each of the above generates a SIGTRAP. + + + (*) On-Chip Serial Ports + + The FR-V on-chip serial ports are made available as ttyS0 and ttyS1. Note + that if the GDB stub is compiled in, ttyS1 will not actually be available + as it will be being used for the GDB stub. + + These ports can be made by: + + mknod /dev/ttyS0 c 4 64 + mknod /dev/ttyS1 c 4 65 + + + (*) Maskable Interrupts + + Level 15 (Non-maskable) interrupts are dealt with by the GDB stub if + present, and cause a panic if not. If the GDB stub is present, ttyS1's + interrupts are rated at level 15. + + All other interrupts are distributed over the set of available priorities + so that no IRQs are shared where possible. The arch interrupt handling + routines attempt to disentangle the various sources available through the + CPU's own multiplexor, and those on off-CPU peripherals. + + + (*) Accessing PCI Devices + + Where PCI is available, care must be taken when dealing with drivers that + access PCI devices. PCI devices present their data in little-endian form, + but the CPU sees it in big-endian form. The macros in asm/io.h try to get + this right, but may not under all circumstances... + + + (*) Ax88796 Ethernet Driver + + The MB93093 PDK board has an Ax88796 ethernet chipset (an NE2000 clone). A + driver has been written to deal specifically with this. The driver + provides MII services for the card. + + The driver can be configured by running make xconfig, and going to: + + (*) Network device support + - turn on "Network device support" + (*) Ethernet (10 or 100Mbit) + - turn on "Ethernet (10 or 100Mbit)" + - turn on "AX88796 NE2000 compatible chipset" + + The driver can be found in: + + drivers/net/ax88796.c + include/asm/ax88796.h + + + (*) WorkRAM Driver + + This driver provides a character device that permits access to the WorkRAM + that can be found on the FR451 CPU. Each page is accessible through a + separate minor number, thereby permitting each page to have its own + filesystem permissions set on the device file. + + The device files should be: + + mknod /dev/frv/workram0 c 240 0 + mknod /dev/frv/workram1 c 240 1 + mknod /dev/frv/workram2 c 240 2 + ... + + The driver will not permit the opening of any device file that does not + correspond to at least a partial page of WorkRAM. So the first device file + is the only one available on the FR451. If any other CPU is detected, none + of the devices will be openable. + + The devices can be accessed with read, write and llseek, and can also be + mmapped. If they're mmapped, they will only map at the appropriate + 0x7e8nnnnn address on linux and at the 0xfe8nnnnn address on uClinux. If + MAP_FIXED is not specified, the appropriate address will be chosen anyway. + + The mappings must be MAP_SHARED not MAP_PRIVATE, and must not be + PROT_EXEC. They must also start at file offset 0, and must not be longer + than one page in size. + + This driver can be configured by running make xconfig, and going to: + + (*) Character devices + - turn on "Fujitsu FR-V CPU WorkRAM support" + + + (*) Dynamic data cache write mode changing + + It is possible to view and to change the data cache's write mode through + the /proc/sys/frv/cache-mode file while the kernel is running. There are + two modes available: + + NAME MEANING + ===== ========================================== + wthru Data cache is in Write-Through mode + wback Data cache is in Write-Back/Copy-Back mode + + To read the cache mode: + + # cat /proc/sys/frv/cache-mode + wthru + + To change the cache mode: + + # echo wback >/proc/sys/frv/cache-mode + # cat /proc/sys/frv/cache-mode + wback + + + (*) MMU Context IDs and Pinning + + On MMU Linux the CPU supports the concept of a context ID in its MMU to + make it more efficient (TLB entries are labelled with a context ID to link + them to specific tasks). + + Normally once a context ID is allocated, it will remain affixed to a task + or CLONE_VM'd group of tasks for as long as it exists. However, since the + kernel is capable of supporting more tasks than there are possible ID + numbers, the kernel will pass context IDs from one task to another if + there are insufficient available. + + The context ID currently in use by a task can be viewed in /proc: + + # grep CXNR /proc/1/status + CXNR: 1 + + Note that kernel threads do not have a userspace context, and so will not + show a CXNR entry in that file. + + Under some circumstances, however, it is desirable to pin a context ID on + a process such that the kernel won't pass it on. This can be done by + writing the process ID of the target process to a special file: + + # echo 17 >/proc/sys/frv/pin-cxnr + + Reading from the file will then show the context ID pinned. + + # cat /proc/sys/frv/pin-cxnr + 4 + + The context ID will remain pinned as long as any process is using that + context, i.e.: when the all the subscribing processes have exited or + exec'd; or when an unpinning request happens: + + # echo 0 >/proc/sys/frv/pin-cxnr + + When there isn't a pinned context, the file shows -1: + + # cat /proc/sys/frv/pin-cxnr + -1 diff --git a/Documentation/fujitsu/frv/gdbinit b/Documentation/fujitsu/frv/gdbinit new file mode 100644 index 000000000000..51517b6f307f --- /dev/null +++ b/Documentation/fujitsu/frv/gdbinit @@ -0,0 +1,102 @@ +set remotebreak 1 + +define _amr + +printf "AMRx DAMR IAMR \n" +printf "==== ===================== =====================\n" +printf "amr0 : L:%08lx P:%08lx : L:%08lx P:%08lx\n",__debug_mmu.damr[0x0].L,__debug_mmu.damr[0x0].P,__debug_mmu.iamr[0x0].L,__debug_mmu.iamr[0x0].P +printf "amr1 : L:%08lx P:%08lx : L:%08lx P:%08lx\n",__debug_mmu.damr[0x1].L,__debug_mmu.damr[0x1].P,__debug_mmu.iamr[0x1].L,__debug_mmu.iamr[0x1].P +printf "amr2 : L:%08lx P:%08lx : L:%08lx P:%08lx\n",__debug_mmu.damr[0x2].L,__debug_mmu.damr[0x2].P,__debug_mmu.iamr[0x2].L,__debug_mmu.iamr[0x2].P +printf "amr3 : L:%08lx P:%08lx : L:%08lx P:%08lx\n",__debug_mmu.damr[0x3].L,__debug_mmu.damr[0x3].P,__debug_mmu.iamr[0x3].L,__debug_mmu.iamr[0x3].P +printf "amr4 : L:%08lx P:%08lx : L:%08lx P:%08lx\n",__debug_mmu.damr[0x4].L,__debug_mmu.damr[0x4].P,__debug_mmu.iamr[0x4].L,__debug_mmu.iamr[0x4].P +printf "amr5 : L:%08lx P:%08lx : L:%08lx P:%08lx\n",__debug_mmu.damr[0x5].L,__debug_mmu.damr[0x5].P,__debug_mmu.iamr[0x5].L,__debug_mmu.iamr[0x5].P +printf "amr6 : L:%08lx P:%08lx : L:%08lx P:%08lx\n",__debug_mmu.damr[0x6].L,__debug_mmu.damr[0x6].P,__debug_mmu.iamr[0x6].L,__debug_mmu.iamr[0x6].P +printf "amr7 : L:%08lx P:%08lx : L:%08lx P:%08lx\n",__debug_mmu.damr[0x7].L,__debug_mmu.damr[0x7].P,__debug_mmu.iamr[0x7].L,__debug_mmu.iamr[0x7].P + +printf "amr8 : L:%08lx P:%08lx\n",__debug_mmu.damr[0x8].L,__debug_mmu.damr[0x8].P +printf "amr9 : L:%08lx P:%08lx\n",__debug_mmu.damr[0x9].L,__debug_mmu.damr[0x9].P +printf "amr10: L:%08lx P:%08lx\n",__debug_mmu.damr[0xa].L,__debug_mmu.damr[0xa].P +printf "amr11: L:%08lx P:%08lx\n",__debug_mmu.damr[0xb].L,__debug_mmu.damr[0xb].P + +end + + +define _tlb +printf "tlb[0x00]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x0].L,__debug_mmu.tlb[0x0].P,__debug_mmu.tlb[0x40+0x0].L,__debug_mmu.tlb[0x40+0x0].P +printf "tlb[0x01]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x1].L,__debug_mmu.tlb[0x1].P,__debug_mmu.tlb[0x40+0x1].L,__debug_mmu.tlb[0x40+0x1].P +printf "tlb[0x02]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x2].L,__debug_mmu.tlb[0x2].P,__debug_mmu.tlb[0x40+0x2].L,__debug_mmu.tlb[0x40+0x2].P +printf "tlb[0x03]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x3].L,__debug_mmu.tlb[0x3].P,__debug_mmu.tlb[0x40+0x3].L,__debug_mmu.tlb[0x40+0x3].P +printf "tlb[0x04]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x4].L,__debug_mmu.tlb[0x4].P,__debug_mmu.tlb[0x40+0x4].L,__debug_mmu.tlb[0x40+0x4].P +printf "tlb[0x05]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x5].L,__debug_mmu.tlb[0x5].P,__debug_mmu.tlb[0x40+0x5].L,__debug_mmu.tlb[0x40+0x5].P +printf "tlb[0x06]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x6].L,__debug_mmu.tlb[0x6].P,__debug_mmu.tlb[0x40+0x6].L,__debug_mmu.tlb[0x40+0x6].P +printf "tlb[0x07]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x7].L,__debug_mmu.tlb[0x7].P,__debug_mmu.tlb[0x40+0x7].L,__debug_mmu.tlb[0x40+0x7].P +printf "tlb[0x08]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x8].L,__debug_mmu.tlb[0x8].P,__debug_mmu.tlb[0x40+0x8].L,__debug_mmu.tlb[0x40+0x8].P +printf "tlb[0x09]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x9].L,__debug_mmu.tlb[0x9].P,__debug_mmu.tlb[0x40+0x9].L,__debug_mmu.tlb[0x40+0x9].P +printf "tlb[0x0a]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0xa].L,__debug_mmu.tlb[0xa].P,__debug_mmu.tlb[0x40+0xa].L,__debug_mmu.tlb[0x40+0xa].P +printf "tlb[0x0b]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0xb].L,__debug_mmu.tlb[0xb].P,__debug_mmu.tlb[0x40+0xb].L,__debug_mmu.tlb[0x40+0xb].P +printf "tlb[0x0c]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0xc].L,__debug_mmu.tlb[0xc].P,__debug_mmu.tlb[0x40+0xc].L,__debug_mmu.tlb[0x40+0xc].P +printf "tlb[0x0d]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0xd].L,__debug_mmu.tlb[0xd].P,__debug_mmu.tlb[0x40+0xd].L,__debug_mmu.tlb[0x40+0xd].P +printf "tlb[0x0e]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0xe].L,__debug_mmu.tlb[0xe].P,__debug_mmu.tlb[0x40+0xe].L,__debug_mmu.tlb[0x40+0xe].P +printf "tlb[0x0f]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0xf].L,__debug_mmu.tlb[0xf].P,__debug_mmu.tlb[0x40+0xf].L,__debug_mmu.tlb[0x40+0xf].P +printf "tlb[0x10]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x10].L,__debug_mmu.tlb[0x10].P,__debug_mmu.tlb[0x40+0x10].L,__debug_mmu.tlb[0x40+0x10].P +printf "tlb[0x11]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x11].L,__debug_mmu.tlb[0x11].P,__debug_mmu.tlb[0x40+0x11].L,__debug_mmu.tlb[0x40+0x11].P +printf "tlb[0x12]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x12].L,__debug_mmu.tlb[0x12].P,__debug_mmu.tlb[0x40+0x12].L,__debug_mmu.tlb[0x40+0x12].P +printf "tlb[0x13]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x13].L,__debug_mmu.tlb[0x13].P,__debug_mmu.tlb[0x40+0x13].L,__debug_mmu.tlb[0x40+0x13].P +printf "tlb[0x14]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x14].L,__debug_mmu.tlb[0x14].P,__debug_mmu.tlb[0x40+0x14].L,__debug_mmu.tlb[0x40+0x14].P +printf "tlb[0x15]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x15].L,__debug_mmu.tlb[0x15].P,__debug_mmu.tlb[0x40+0x15].L,__debug_mmu.tlb[0x40+0x15].P +printf "tlb[0x16]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x16].L,__debug_mmu.tlb[0x16].P,__debug_mmu.tlb[0x40+0x16].L,__debug_mmu.tlb[0x40+0x16].P +printf "tlb[0x17]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x17].L,__debug_mmu.tlb[0x17].P,__debug_mmu.tlb[0x40+0x17].L,__debug_mmu.tlb[0x40+0x17].P +printf "tlb[0x18]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x18].L,__debug_mmu.tlb[0x18].P,__debug_mmu.tlb[0x40+0x18].L,__debug_mmu.tlb[0x40+0x18].P +printf "tlb[0x19]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x19].L,__debug_mmu.tlb[0x19].P,__debug_mmu.tlb[0x40+0x19].L,__debug_mmu.tlb[0x40+0x19].P +printf "tlb[0x1a]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x1a].L,__debug_mmu.tlb[0x1a].P,__debug_mmu.tlb[0x40+0x1a].L,__debug_mmu.tlb[0x40+0x1a].P +printf "tlb[0x1b]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x1b].L,__debug_mmu.tlb[0x1b].P,__debug_mmu.tlb[0x40+0x1b].L,__debug_mmu.tlb[0x40+0x1b].P +printf "tlb[0x1c]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x1c].L,__debug_mmu.tlb[0x1c].P,__debug_mmu.tlb[0x40+0x1c].L,__debug_mmu.tlb[0x40+0x1c].P +printf "tlb[0x1d]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x1d].L,__debug_mmu.tlb[0x1d].P,__debug_mmu.tlb[0x40+0x1d].L,__debug_mmu.tlb[0x40+0x1d].P +printf "tlb[0x1e]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x1e].L,__debug_mmu.tlb[0x1e].P,__debug_mmu.tlb[0x40+0x1e].L,__debug_mmu.tlb[0x40+0x1e].P +printf "tlb[0x1f]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x1f].L,__debug_mmu.tlb[0x1f].P,__debug_mmu.tlb[0x40+0x1f].L,__debug_mmu.tlb[0x40+0x1f].P +printf "tlb[0x20]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x20].L,__debug_mmu.tlb[0x20].P,__debug_mmu.tlb[0x40+0x20].L,__debug_mmu.tlb[0x40+0x20].P +printf "tlb[0x21]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x21].L,__debug_mmu.tlb[0x21].P,__debug_mmu.tlb[0x40+0x21].L,__debug_mmu.tlb[0x40+0x21].P +printf "tlb[0x22]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x22].L,__debug_mmu.tlb[0x22].P,__debug_mmu.tlb[0x40+0x22].L,__debug_mmu.tlb[0x40+0x22].P +printf "tlb[0x23]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x23].L,__debug_mmu.tlb[0x23].P,__debug_mmu.tlb[0x40+0x23].L,__debug_mmu.tlb[0x40+0x23].P +printf "tlb[0x24]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x24].L,__debug_mmu.tlb[0x24].P,__debug_mmu.tlb[0x40+0x24].L,__debug_mmu.tlb[0x40+0x24].P +printf "tlb[0x25]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x25].L,__debug_mmu.tlb[0x25].P,__debug_mmu.tlb[0x40+0x25].L,__debug_mmu.tlb[0x40+0x25].P +printf "tlb[0x26]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x26].L,__debug_mmu.tlb[0x26].P,__debug_mmu.tlb[0x40+0x26].L,__debug_mmu.tlb[0x40+0x26].P +printf "tlb[0x27]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x27].L,__debug_mmu.tlb[0x27].P,__debug_mmu.tlb[0x40+0x27].L,__debug_mmu.tlb[0x40+0x27].P +printf "tlb[0x28]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x28].L,__debug_mmu.tlb[0x28].P,__debug_mmu.tlb[0x40+0x28].L,__debug_mmu.tlb[0x40+0x28].P +printf "tlb[0x29]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x29].L,__debug_mmu.tlb[0x29].P,__debug_mmu.tlb[0x40+0x29].L,__debug_mmu.tlb[0x40+0x29].P +printf "tlb[0x2a]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x2a].L,__debug_mmu.tlb[0x2a].P,__debug_mmu.tlb[0x40+0x2a].L,__debug_mmu.tlb[0x40+0x2a].P +printf "tlb[0x2b]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x2b].L,__debug_mmu.tlb[0x2b].P,__debug_mmu.tlb[0x40+0x2b].L,__debug_mmu.tlb[0x40+0x2b].P +printf "tlb[0x2c]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x2c].L,__debug_mmu.tlb[0x2c].P,__debug_mmu.tlb[0x40+0x2c].L,__debug_mmu.tlb[0x40+0x2c].P +printf "tlb[0x2d]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x2d].L,__debug_mmu.tlb[0x2d].P,__debug_mmu.tlb[0x40+0x2d].L,__debug_mmu.tlb[0x40+0x2d].P +printf "tlb[0x2e]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x2e].L,__debug_mmu.tlb[0x2e].P,__debug_mmu.tlb[0x40+0x2e].L,__debug_mmu.tlb[0x40+0x2e].P +printf "tlb[0x2f]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x2f].L,__debug_mmu.tlb[0x2f].P,__debug_mmu.tlb[0x40+0x2f].L,__debug_mmu.tlb[0x40+0x2f].P +printf "tlb[0x30]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x30].L,__debug_mmu.tlb[0x30].P,__debug_mmu.tlb[0x40+0x30].L,__debug_mmu.tlb[0x40+0x30].P +printf "tlb[0x31]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x31].L,__debug_mmu.tlb[0x31].P,__debug_mmu.tlb[0x40+0x31].L,__debug_mmu.tlb[0x40+0x31].P +printf "tlb[0x32]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x32].L,__debug_mmu.tlb[0x32].P,__debug_mmu.tlb[0x40+0x32].L,__debug_mmu.tlb[0x40+0x32].P +printf "tlb[0x33]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x33].L,__debug_mmu.tlb[0x33].P,__debug_mmu.tlb[0x40+0x33].L,__debug_mmu.tlb[0x40+0x33].P +printf "tlb[0x34]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x34].L,__debug_mmu.tlb[0x34].P,__debug_mmu.tlb[0x40+0x34].L,__debug_mmu.tlb[0x40+0x34].P +printf "tlb[0x35]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x35].L,__debug_mmu.tlb[0x35].P,__debug_mmu.tlb[0x40+0x35].L,__debug_mmu.tlb[0x40+0x35].P +printf "tlb[0x36]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x36].L,__debug_mmu.tlb[0x36].P,__debug_mmu.tlb[0x40+0x36].L,__debug_mmu.tlb[0x40+0x36].P +printf "tlb[0x37]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x37].L,__debug_mmu.tlb[0x37].P,__debug_mmu.tlb[0x40+0x37].L,__debug_mmu.tlb[0x40+0x37].P +printf "tlb[0x38]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x38].L,__debug_mmu.tlb[0x38].P,__debug_mmu.tlb[0x40+0x38].L,__debug_mmu.tlb[0x40+0x38].P +printf "tlb[0x39]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x39].L,__debug_mmu.tlb[0x39].P,__debug_mmu.tlb[0x40+0x39].L,__debug_mmu.tlb[0x40+0x39].P +printf "tlb[0x3a]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x3a].L,__debug_mmu.tlb[0x3a].P,__debug_mmu.tlb[0x40+0x3a].L,__debug_mmu.tlb[0x40+0x3a].P +printf "tlb[0x3b]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x3b].L,__debug_mmu.tlb[0x3b].P,__debug_mmu.tlb[0x40+0x3b].L,__debug_mmu.tlb[0x40+0x3b].P +printf "tlb[0x3c]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x3c].L,__debug_mmu.tlb[0x3c].P,__debug_mmu.tlb[0x40+0x3c].L,__debug_mmu.tlb[0x40+0x3c].P +printf "tlb[0x3d]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x3d].L,__debug_mmu.tlb[0x3d].P,__debug_mmu.tlb[0x40+0x3d].L,__debug_mmu.tlb[0x40+0x3d].P +printf "tlb[0x3e]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x3e].L,__debug_mmu.tlb[0x3e].P,__debug_mmu.tlb[0x40+0x3e].L,__debug_mmu.tlb[0x40+0x3e].P +printf "tlb[0x3f]: %08lx %08lx %08lx %08lx\n",__debug_mmu.tlb[0x3f].L,__debug_mmu.tlb[0x3f].P,__debug_mmu.tlb[0x40+0x3f].L,__debug_mmu.tlb[0x40+0x3f].P +end + + +define _pgd +p (pgd_t[0x40])*(pgd_t*)(__debug_mmu.damr[0x3].L) +end + +define _ptd_i +p (pte_t[0x1000])*(pte_t*)(__debug_mmu.damr[0x4].L) +end + +define _ptd_d +p (pte_t[0x1000])*(pte_t*)(__debug_mmu.damr[0x5].L) +end diff --git a/Documentation/fujitsu/frv/gdbstub.txt b/Documentation/fujitsu/frv/gdbstub.txt new file mode 100644 index 000000000000..6ce5aa9abbc5 --- /dev/null +++ b/Documentation/fujitsu/frv/gdbstub.txt @@ -0,0 +1,130 @@ + ==================== + DEBUGGING FR-V LINUX + ==================== + + +The kernel contains a GDB stub that talks GDB remote protocol across a serial +port. This permits GDB to single step through the kernel, set breakpoints and +trap exceptions that happen in kernel space and interrupt execution. It also +permits the NMI interrupt button or serial port events to jump the kernel into +the debugger. + +On the CPUs that have on-chip UARTs (FR400, FR403, FR405, FR555), the +GDB stub hijacks a serial port for its own purposes, and makes it +generate level 15 interrupts (NMI). The kernel proper cannot see the serial +port in question under these conditions. + +On the MB93091-VDK CPU boards, the GDB stub uses UART1, which would otherwise +be /dev/ttyS1. On the MB93093-PDK, the GDB stub uses UART0. Therefore, on the +PDK there is no externally accessible serial port and the serial port to +which the touch screen is attached becomes /dev/ttyS0. + +Note that the GDB stub runs entirely within CPU debug mode, and so should not +incur any exceptions or interrupts whilst it is active. In particular, note +that the clock will lose time since it is implemented in software. + + +================== +KERNEL PREPARATION +================== + +Firstly, a debuggable kernel must be built. To do this, unpack the kernel tree +and copy the configuration that you wish to use to .config. Then reconfigure +the following things on the "Kernel Hacking" tab: + + (*) "Include debugging information" + + Set this to "Y". This causes all C and Assembly files to be compiled + to include debugging information. + + (*) "In-kernel GDB stub" + + Set this to "Y". This causes the GDB stub to be compiled into the + kernel. + + (*) "Immediate activation" + + Set this to "Y" if you want the GDB stub to activate as soon as possible + and wait for GDB to connect. This allows you to start tracing right from + the beginning of start_kernel() in init/main.c. + + (*) "Console through GDB stub" + + Set this to "Y" if you wish to be able to use "console=gdb0" on the + command line. That tells the kernel to pass system console messages to + GDB (which then prints them on its standard output). This is useful when + debugging the serial drivers that'd otherwise be used to pass console + messages to the outside world. + +Then build as usual, download to the board and execute. Note that if +"Immediate activation" was selected, then the kernel will wait for GDB to +attach. If not, then the kernel will boot immediately and GDB will have to +interupt it or wait for an exception to occur if before doing anything with +the kernel. + + +========================= +KERNEL DEBUGGING WITH GDB +========================= + +Set the serial port on the computer that's going to run GDB to the appropriate +baud rate. Assuming the board's debug port is connected to ttyS0/COM1 on the +computer doing the debugging: + + stty -F /dev/ttyS0 115200 + +Then start GDB in the base of the kernel tree: + + frv-uclinux-gdb linux [uClinux] + +Or: + + frv-uclinux-gdb vmlinux [MMU linux] + +When the prompt appears: + + GNU gdb frv-031024 + Copyright 2003 Free Software Foundation, Inc. + GDB is free software, covered by the GNU General Public License, and you are + welcome to change it and/or distribute copies of it under certain conditions. + Type "show copying" to see the conditions. + There is absolutely no warranty for GDB. Type "show warranty" for details. + This GDB was configured as "--host=i686-pc-linux-gnu --target=frv-uclinux"... + (gdb) + +Attach to the board like this: + + (gdb) target remote /dev/ttyS0 + Remote debugging using /dev/ttyS0 + start_kernel () at init/main.c:395 + (gdb) + +This should show the appropriate lines from the source too. The kernel can +then be debugged almost as if it's any other program. + + +=============================== +INTERRUPTING THE RUNNING KERNEL +=============================== + +The kernel can be interrupted whilst it is running, causing a jump back to the +GDB stub and the debugger: + + (*) Pressing Ctrl-C in GDB. This will cause GDB to try and interrupt the + kernel by sending an RS232 BREAK over the serial line to the GDB + stub. This will (mostly) immediately interrupt the kernel and return it + to the debugger. + + (*) Pressing the NMI button on the board will also cause a jump into the + debugger. + + (*) Setting a software breakpoint. This sets a break instruction at the + desired location which the GDB stub then traps the exception for. + + (*) Setting a hardware breakpoint. The GDB stub is capable of using the IBAR + and DBAR registers to assist debugging. + +Furthermore, the GDB stub will intercept a number of exceptions automatically +if they are caused by kernel execution. It will also intercept BUG() macro +invokation. + diff --git a/Documentation/fujitsu/frv/mmu-layout.txt b/Documentation/fujitsu/frv/mmu-layout.txt new file mode 100644 index 000000000000..11dcc5679887 --- /dev/null +++ b/Documentation/fujitsu/frv/mmu-layout.txt @@ -0,0 +1,306 @@ + ================================= + FR451 MMU LINUX MEMORY MANAGEMENT + ================================= + +============ +MMU HARDWARE +============ + +FR451 MMU Linux puts the MMU into EDAT mode whilst running. This means that it uses both the SAT +registers and the DAT TLB to perform address translation. + +There are 8 IAMLR/IAMPR register pairs and 16 DAMLR/DAMPR register pairs for SAT mode. + +In DAT mode, there is also a TLB organised in cache format as 64 lines x 2 ways. Each line spans a +16KB range of addresses, but can match a larger region. + + +=========================== +MEMORY MANAGEMENT REGISTERS +=========================== + +Certain control registers are used by the kernel memory management routines: + + REGISTERS USAGE + ====================== ================================================== + IAMR0, DAMR0 Kernel image and data mappings + IAMR1, DAMR1 First-chance TLB lookup mapping + DAMR2 Page attachment for cache flush by page + DAMR3 Current PGD mapping + SCR0, DAMR4 Instruction TLB PGE/PTD cache + SCR1, DAMR5 Data TLB PGE/PTD cache + DAMR6-10 kmap_atomic() mappings + DAMR11 I/O mapping + CXNR mm_struct context ID + TTBR Page directory (PGD) pointer (physical address) + + +===================== +GENERAL MEMORY LAYOUT +===================== + +The physical memory layout is as follows: + + PHYSICAL ADDRESS CONTROLLER DEVICE + =================== ============== ======================================= + 00000000 - BFFFFFFF SDRAM SDRAM area + E0000000 - EFFFFFFF L-BUS CS2# VDK SLBUS/PCI window + F0000000 - F0FFFFFF L-BUS CS5# MB93493 CSC area (DAV daughter board) + F1000000 - F1FFFFFF L-BUS CS7# (CB70 CPU-card PCMCIA port I/O space) + FC000000 - FC0FFFFF L-BUS CS1# VDK MB86943 config space + FC100000 - FC1FFFFF L-BUS CS6# DM9000 NIC I/O space + FC200000 - FC2FFFFF L-BUS CS3# MB93493 CSR area (DAV daughter board) + FD000000 - FDFFFFFF L-BUS CS4# (CB70 CPU-card extra flash space) + FE000000 - FEFFFFFF Internal CPU peripherals + FF000000 - FF1FFFFF L-BUS CS0# Flash 1 + FF200000 - FF3FFFFF L-BUS CS0# Flash 2 + FFC00000 - FFC0001F L-BUS CS0# FPGA + +The virtual memory layout is: + + VIRTUAL ADDRESS PHYSICAL TRANSLATOR FLAGS SIZE OCCUPATION + ================= ======== ============== ======= ======= =================================== + 00004000-BFFFFFFF various TLB,xAMR1 D-N-??V 3GB Userspace + C0000000-CFFFFFFF 00000000 xAMPR0 -L-S--V 256MB Kernel image and data + D0000000-D7FFFFFF various TLB,xAMR1 D-NS??V 128MB vmalloc area + D8000000-DBFFFFFF various TLB,xAMR1 D-NS??V 64MB kmap() area + DC000000-DCFFFFFF various TLB 1MB Secondary kmap_atomic() frame + DD000000-DD27FFFF various DAMR 160KB Primary kmap_atomic() frame + DD040000 DAMR2/IAMR2 -L-S--V page Page cache flush attachment point + DD080000 DAMR3 -L-SC-V page Page Directory (PGD) + DD0C0000 DAMR4 -L-SC-V page Cached insn TLB Page Table lookup + DD100000 DAMR5 -L-SC-V page Cached data TLB Page Table lookup + DD140000 DAMR6 -L-S--V page kmap_atomic(KM_BOUNCE_READ) + DD180000 DAMR7 -L-S--V page kmap_atomic(KM_SKB_SUNRPC_DATA) + DD1C0000 DAMR8 -L-S--V page kmap_atomic(KM_SKB_DATA_SOFTIRQ) + DD200000 DAMR9 -L-S--V page kmap_atomic(KM_USER0) + DD240000 DAMR10 -L-S--V page kmap_atomic(KM_USER1) + E0000000-FFFFFFFF E0000000 DAMR11 -L-SC-V 512MB I/O region + +IAMPR1 and DAMPR1 are used as an extension to the TLB. + + +==================== +KMAP AND KMAP_ATOMIC +==================== + +To access pages in the page cache (which may not be directly accessible if highmem is available), +the kernel calls kmap(), does the access and then calls kunmap(); or it calls kmap_atomic(), does +the access and then calls kunmap_atomic(). + +kmap() creates an attachment between an arbitrary inaccessible page and a range of virtual +addresses by installing a PTE in a special page table. The kernel can then access this page as it +wills. When it's finished, the kernel calls kunmap() to clear the PTE. + +kmap_atomic() does something slightly different. In the interests of speed, it chooses one of two +strategies: + + (1) If possible, kmap_atomic() attaches the requested page to one of DAMPR5 through DAMPR10 + register pairs; and the matching kunmap_atomic() clears the DAMPR. This makes high memory + support really fast as there's no need to flush the TLB or modify the page tables. The DAMLR + registers being used for this are preset during boot and don't change over the lifetime of the + process. There's a direct mapping between the first few kmap_atomic() types, DAMR number and + virtual address slot. + + However, there are more kmap_atomic() types defined than there are DAMR registers available, + so we fall back to: + + (2) kmap_atomic() uses a slot in the secondary frame (determined by the type parameter), and then + locks an entry in the TLB to translate that slot to the specified page. The number of slots is + obviously limited, and their positions are controlled such that each slot is matched by a + different line in the TLB. kunmap() ejects the entry from the TLB. + +Note that the first three kmap atomic types are really just declared as placeholders. The DAMPR +registers involved are actually modified directly. + +Also note that kmap() itself may sleep, kmap_atomic() may never sleep and both always succeed; +furthermore, a driver using kmap() may sleep before calling kunmap(), but may not sleep before +calling kunmap_atomic() if it had previously called kmap_atomic(). + + +=============================== +USING MORE THAN 256MB OF MEMORY +=============================== + +The kernel cannot access more than 256MB of memory directly. The physical layout, however, permits +up to 3GB of SDRAM (possibly 3.25GB) to be made available. By using CONFIG_HIGHMEM, the kernel can +allow userspace (by way of page tables) and itself (by way of kmap) to deal with the memory +allocation. + +External devices can, of course, still DMA to and from all of the SDRAM, even if the kernel can't +see it directly. The kernel translates page references into real addresses for communicating to the +devices. + + +=================== +PAGE TABLE TOPOLOGY +=================== + +The page tables are arranged in 2-layer format. There is a middle layer (PMD) that would be used in +3-layer format tables but that is folded into the top layer (PGD) and so consumes no extra memory +or processing power. + + +------+ PGD PMD + | TTBR |--->+-------------------+ + +------+ | | : STE | + | PGE0 | PME0 : STE | + | | : STE | + +-------------------+ Page Table + | | : STE -------------->+--------+ +0x0000 + | PGE1 | PME0 : STE -----------+ | PTE0 | + | | : STE -------+ | +--------+ + +-------------------+ | | | PTE63 | + | | : STE | | +-->+--------+ +0x0100 + | PGE2 | PME0 : STE | | | PTE64 | + | | : STE | | +--------+ + +-------------------+ | | PTE127 | + | | : STE | +------>+--------+ +0x0200 + | PGE3 | PME0 : STE | | PTE128 | + | | : STE | +--------+ + +-------------------+ | PTE191 | + +--------+ +0x0300 + +Each Page Directory (PGD) is 16KB (page size) in size and is divided into 64 entries (PGEs). Each +PGE contains one Page Mid Directory (PMD). + +Each PMD is 256 bytes in size and contains a single entry (PME). Each PME holds 64 FR451 MMU +segment table entries of 4 bytes apiece. Each PME "points to" a page table. In practice, each STE +points to a subset of the page table, the first to PT+0x0000, the second to PT+0x0100, the third to +PT+0x200, and so on. + +Each PGE and PME covers 64MB of the total virtual address space. + +Each Page Table (PTD) is 16KB (page size) in size, and is divided into 4096 entries (PTEs). Each +entry can point to one 16KB page. In practice, each Linux page table is subdivided into 64 FR451 +MMU page tables. But they are all grouped together to make management easier, in particular rmap +support is then trivial. + +Grouping page tables in this fashion makes PGE caching in SCR0/SCR1 more efficient because the +coverage of the cached item is greater. + +Page tables for the vmalloc area are allocated at boot time and shared between all mm_structs. + + +================= +USER SPACE LAYOUT +================= + +For MMU capable Linux, the regions userspace code are allowed to access are kept entirely separate +from those dedicated to the kernel: + + VIRTUAL ADDRESS SIZE PURPOSE + ================= ===== =================================== + 00000000-00003fff 4KB NULL pointer access trap + 00004000-01ffffff ~32MB lower mmap space (grows up) + 02000000-021fffff 2MB Stack space (grows down from top) + 02200000-nnnnnnnn Executable mapping + nnnnnnnn- brk space (grows up) + -bfffffff upper mmap space (grows down) + +This is so arranged so as to make best use of the 16KB page tables and the way in which PGEs/PMEs +are cached by the TLB handler. The lower mmap space is filled first, and then the upper mmap space +is filled. + + +=============================== +GDB-STUB MMU DEBUGGING SERVICES +=============================== + +The gdb-stub included in this kernel provides a number of services to aid in the debugging of MMU +related kernel services: + + (*) Every time the kernel stops, certain state information is dumped into __debug_mmu. This + variable is defined in arch/frv/kernel/gdb-stub.c. Note that the gdbinit file in this + directory has some useful macros for dealing with this. + + (*) __debug_mmu.tlb[] + + This receives the current TLB contents. This can be viewed with the _tlb GDB macro: + + (gdb) _tlb + tlb[0x00]: 01000005 00718203 01000002 00718203 + tlb[0x01]: 01004002 006d4201 01004005 006d4203 + tlb[0x02]: 01008002 006d0201 01008006 00004200 + tlb[0x03]: 0100c006 007f4202 0100c002 0064c202 + tlb[0x04]: 01110005 00774201 01110002 00774201 + tlb[0x05]: 01114005 00770201 01114002 00770201 + tlb[0x06]: 01118002 0076c201 01118005 0076c201 + ... + tlb[0x3d]: 010f4002 00790200 001f4002 0054ca02 + tlb[0x3e]: 010f8005 0078c201 010f8002 0078c201 + tlb[0x3f]: 001fc002 0056ca01 001fc005 00538a01 + + (*) __debug_mmu.iamr[] + (*) __debug_mmu.damr[] + + These receive the current IAMR and DAMR contents. These can be viewed with with the _amr + GDB macro: + + (gdb) _amr + AMRx DAMR IAMR + ==== ===================== ===================== + amr0 : L:c0000000 P:00000cb9 : L:c0000000 P:000004b9 + amr1 : L:01070005 P:006f9203 : L:0102c005 P:006a1201 + amr2 : L:d8d00000 P:00000000 : L:d8d00000 P:00000000 + amr3 : L:d8d04000 P:00534c0d : L:00000000 P:00000000 + amr4 : L:d8d08000 P:00554c0d : L:00000000 P:00000000 + amr5 : L:d8d0c000 P:00554c0d : L:00000000 P:00000000 + amr6 : L:d8d10000 P:00000000 : L:00000000 P:00000000 + amr7 : L:d8d14000 P:00000000 : L:00000000 P:00000000 + amr8 : L:d8d18000 P:00000000 + amr9 : L:d8d1c000 P:00000000 + amr10: L:d8d20000 P:00000000 + amr11: L:e0000000 P:e0000ccd + + (*) The current task's page directory is bound to DAMR3. + + This can be viewed with the _pgd GDB macro: + + (gdb) _pgd + $3 = {{pge = {{ste = {0x554001, 0x554101, 0x554201, 0x554301, 0x554401, + 0x554501, 0x554601, 0x554701, 0x554801, 0x554901, 0x554a01, + 0x554b01, 0x554c01, 0x554d01, 0x554e01, 0x554f01, 0x555001, + 0x555101, 0x555201, 0x555301, 0x555401, 0x555501, 0x555601, + 0x555701, 0x555801, 0x555901, 0x555a01, 0x555b01, 0x555c01, + 0x555d01, 0x555e01, 0x555f01, 0x556001, 0x556101, 0x556201, + 0x556301, 0x556401, 0x556501, 0x556601, 0x556701, 0x556801, + 0x556901, 0x556a01, 0x556b01, 0x556c01, 0x556d01, 0x556e01, + 0x556f01, 0x557001, 0x557101, 0x557201, 0x557301, 0x557401, + 0x557501, 0x557601, 0x557701, 0x557801, 0x557901, 0x557a01, + 0x557b01, 0x557c01, 0x557d01, 0x557e01, 0x557f01}}}}, {pge = {{ + ste = {0x0 <repeats 64 times>}}}} <repeats 51 times>, {pge = {{ste = { + 0x248001, 0x248101, 0x248201, 0x248301, 0x248401, 0x248501, + 0x248601, 0x248701, 0x248801, 0x248901, 0x248a01, 0x248b01, + 0x248c01, 0x248d01, 0x248e01, 0x248f01, 0x249001, 0x249101, + 0x249201, 0x249301, 0x249401, 0x249501, 0x249601, 0x249701, + 0x249801, 0x249901, 0x249a01, 0x249b01, 0x249c01, 0x249d01, + 0x249e01, 0x249f01, 0x24a001, 0x24a101, 0x24a201, 0x24a301, + 0x24a401, 0x24a501, 0x24a601, 0x24a701, 0x24a801, 0x24a901, + 0x24aa01, 0x24ab01, 0x24ac01, 0x24ad01, 0x24ae01, 0x24af01, + 0x24b001, 0x24b101, 0x24b201, 0x24b301, 0x24b401, 0x24b501, + 0x24b601, 0x24b701, 0x24b801, 0x24b901, 0x24ba01, 0x24bb01, + 0x24bc01, 0x24bd01, 0x24be01, 0x24bf01}}}}, {pge = {{ste = { + 0x0 <repeats 64 times>}}}} <repeats 11 times>} + + (*) The PTD last used by the instruction TLB miss handler is attached to DAMR4. + (*) The PTD last used by the data TLB miss handler is attached to DAMR5. + + These can be viewed with the _ptd_i and _ptd_d GDB macros: + + (gdb) _ptd_d + $5 = {{pte = 0x0} <repeats 127 times>, {pte = 0x539b01}, { + pte = 0x0} <repeats 896 times>, {pte = 0x719303}, {pte = 0x6d5303}, { + pte = 0x0}, {pte = 0x0}, {pte = 0x0}, {pte = 0x0}, {pte = 0x0}, { + pte = 0x0}, {pte = 0x0}, {pte = 0x0}, {pte = 0x0}, {pte = 0x6a1303}, { + pte = 0x0} <repeats 12 times>, {pte = 0x709303}, {pte = 0x0}, {pte = 0x0}, + {pte = 0x6fd303}, {pte = 0x6f9303}, {pte = 0x6f5303}, {pte = 0x0}, { + pte = 0x6ed303}, {pte = 0x531b01}, {pte = 0x50db01}, { + pte = 0x0} <repeats 13 times>, {pte = 0x5303}, {pte = 0x7f5303}, { + pte = 0x509b01}, {pte = 0x505b01}, {pte = 0x7c9303}, {pte = 0x7b9303}, { + pte = 0x7b5303}, {pte = 0x7b1303}, {pte = 0x7ad303}, {pte = 0x0}, { + pte = 0x0}, {pte = 0x7a1303}, {pte = 0x0}, {pte = 0x795303}, {pte = 0x0}, { + pte = 0x78d303}, {pte = 0x0}, {pte = 0x0}, {pte = 0x0}, {pte = 0x0}, { + pte = 0x0}, {pte = 0x775303}, {pte = 0x771303}, {pte = 0x76d303}, { + pte = 0x0}, {pte = 0x765303}, {pte = 0x7c5303}, {pte = 0x501b01}, { + pte = 0x4f1b01}, {pte = 0x4edb01}, {pte = 0x0}, {pte = 0x4f9b01}, { + pte = 0x4fdb01}, {pte = 0x0} <repeats 2992 times>} |