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/*
* arch/mips/dec/prom/call_o32.S
*
* O32 interface for the 64 (or N32) ABI.
*
* Copyright (C) 2002 Maciej W. Rozycki
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <asm/asm.h>
#include <asm/regdef.h>
/* Maximum number of arguments supported. Must be even! */
#define O32_ARGC 32
/* Number of static registers we save. */
#define O32_STATC 11
/* Frame size for both of the above. */
#define O32_FRAMESZ (4 * O32_ARGC + SZREG * O32_STATC)
.text
/*
* O32 function call dispatcher, for interfacing 32-bit ROM routines.
*
* The standard 64 (N32) calling sequence is supported, with a0
* holding a function pointer, a1-a7 -- its first seven arguments
* and the stack -- remaining ones (up to O32_ARGC, including a1-a7).
* Static registers, gp and fp are preserved, v0 holds a result.
* This code relies on the called o32 function for sp and ra
* restoration and thus both this dispatcher and the current stack
* have to be placed in a KSEGx (or KUSEG) address space. Any
* pointers passed have to point to addresses within one of these
* spaces as well.
*/
NESTED(call_o32, O32_FRAMESZ, ra)
REG_SUBU sp,O32_FRAMESZ
REG_S ra,O32_FRAMESZ-1*SZREG(sp)
REG_S fp,O32_FRAMESZ-2*SZREG(sp)
REG_S gp,O32_FRAMESZ-3*SZREG(sp)
REG_S s7,O32_FRAMESZ-4*SZREG(sp)
REG_S s6,O32_FRAMESZ-5*SZREG(sp)
REG_S s5,O32_FRAMESZ-6*SZREG(sp)
REG_S s4,O32_FRAMESZ-7*SZREG(sp)
REG_S s3,O32_FRAMESZ-8*SZREG(sp)
REG_S s2,O32_FRAMESZ-9*SZREG(sp)
REG_S s1,O32_FRAMESZ-10*SZREG(sp)
REG_S s0,O32_FRAMESZ-11*SZREG(sp)
move jp,a0
sll a0,a1,zero
sll a1,a2,zero
sll a2,a3,zero
sll a3,a4,zero
sw a5,0x10(sp)
sw a6,0x14(sp)
sw a7,0x18(sp)
PTR_LA t0,O32_FRAMESZ(sp)
PTR_LA t1,0x1c(sp)
li t2,O32_ARGC-7
1:
lw t3,(t0)
REG_ADDU t0,SZREG
sw t3,(t1)
REG_SUBU t2,1
REG_ADDU t1,4
bnez t2,1b
jalr jp
REG_L s0,O32_FRAMESZ-11*SZREG(sp)
REG_L s1,O32_FRAMESZ-10*SZREG(sp)
REG_L s2,O32_FRAMESZ-9*SZREG(sp)
REG_L s3,O32_FRAMESZ-8*SZREG(sp)
REG_L s4,O32_FRAMESZ-7*SZREG(sp)
REG_L s5,O32_FRAMESZ-6*SZREG(sp)
REG_L s6,O32_FRAMESZ-5*SZREG(sp)
REG_L s7,O32_FRAMESZ-4*SZREG(sp)
REG_L gp,O32_FRAMESZ-3*SZREG(sp)
REG_L fp,O32_FRAMESZ-2*SZREG(sp)
REG_L ra,O32_FRAMESZ-1*SZREG(sp)
REG_ADDU sp,O32_FRAMESZ
jr ra
END(call_o32)
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