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| author | H. Peter Anvin <hpa@linux.intel.com> | 2012-05-08 21:22:37 +0300 |
|---|---|---|
| committer | H. Peter Anvin <hpa@linux.intel.com> | 2012-05-08 11:48:03 -0700 |
| commit | e5684ec438a094bec0f7d5c52652c0901b48b613 (patch) | |
| tree | 8cc3cf787a582977ff08ed578907d6df7dbc7e6e /arch/x86/realmode/rm/reboot_32.S | |
| parent | 968ff9ee56f1e3ed4ff4a6d10185865dc77d8f7e (diff) | |
| download | lwn-e5684ec438a094bec0f7d5c52652c0901b48b613.tar.gz lwn-e5684ec438a094bec0f7d5c52652c0901b48b613.zip | |
x86, realmode: Replace open-coded ljmpw with a macro
We cannot code an ljmpw to the real-mode segment directly, because gas
refuses to assemble an ljmp with a symbolic segment. Instead of
open-coding it everywhere, define a macro and use it for this case.
This is specifically an ljmpw from a 16-bit segment. This is okay, as
one should never enter real mode from a 32-bit segment: if one do, the
CPU ends up in a bizarre (and useless) mode sometimes called "unreal
mode" where segments behave like real mode but the default address and
operand sizes is 32 bits.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/1336501366-28617-15-git-send-email-jarkko.sakkinen@intel.com
Diffstat (limited to 'arch/x86/realmode/rm/reboot_32.S')
| -rw-r--r-- | arch/x86/realmode/rm/reboot_32.S | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/arch/x86/realmode/rm/reboot_32.S b/arch/x86/realmode/rm/reboot_32.S index 83803c222b4a..e90f8c4bbae2 100644 --- a/arch/x86/realmode/rm/reboot_32.S +++ b/arch/x86/realmode/rm/reboot_32.S @@ -2,6 +2,7 @@ #include <linux/init.h> #include <asm/segment.h> #include <asm/page_types.h> +#include "realmode.h" /* * The following code and data reboots the machine by switching to real @@ -82,10 +83,7 @@ machine_real_restart_asm16: 2: andb $0x10, %dl movl %edx, %cr0 - .byte 0xea /* ljmpw */ - .word 3f /* Offset */ - .word real_mode_seg /* Segment */ - + LJMPW_RM(3f) 3: testb $0, %al jz bios |