1/* 2 * arch/mips/dec/prom/call_o32.S 3 * 4 * O32 interface for the 64 (or N32) ABI. 5 * 6 * Copyright (C) 2002 Maciej W. Rozycki 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License 10 * as published by the Free Software Foundation; either version 11 * 2 of the License, or (at your option) any later version. 12 */ 13 14#include <asm/asm.h> 15#include <asm/regdef.h> 16 17/* Maximum number of arguments supported. Must be even! */ 18#define O32_ARGC 32 19/* Number of static registers we save. */ 20#define O32_STATC 11 21/* Frame size for static register */ 22#define O32_FRAMESZ (SZREG * O32_STATC) 23/* Frame size on new stack */ 24#define O32_FRAMESZ_NEW (SZREG + 4 * O32_ARGC) 25 26 .text 27 28/* 29 * O32 function call dispatcher, for interfacing 32-bit ROM routines. 30 * 31 * The standard 64 (N32) calling sequence is supported, with a0 32 * holding a function pointer, a1 a new stack pointer, a2-a7 -- its 33 * first six arguments and the stack -- remaining ones (up to O32_ARGC, 34 * including a2-a7). Static registers, gp and fp are preserved, v0 holds 35 * a result. This code relies on the called o32 function for sp and ra 36 * restoration and this dispatcher has to be placed in a KSEGx (or KUSEG) 37 * address space. Any pointers passed have to point to addresses within 38 * one of these spaces as well. 39 */ 40NESTED(call_o32, O32_FRAMESZ, ra) 41 REG_SUBU sp,O32_FRAMESZ 42 43 REG_S ra,O32_FRAMESZ-1*SZREG(sp) 44 REG_S fp,O32_FRAMESZ-2*SZREG(sp) 45 REG_S gp,O32_FRAMESZ-3*SZREG(sp) 46 REG_S s7,O32_FRAMESZ-4*SZREG(sp) 47 REG_S s6,O32_FRAMESZ-5*SZREG(sp) 48 REG_S s5,O32_FRAMESZ-6*SZREG(sp) 49 REG_S s4,O32_FRAMESZ-7*SZREG(sp) 50 REG_S s3,O32_FRAMESZ-8*SZREG(sp) 51 REG_S s2,O32_FRAMESZ-9*SZREG(sp) 52 REG_S s1,O32_FRAMESZ-10*SZREG(sp) 53 REG_S s0,O32_FRAMESZ-11*SZREG(sp) 54 55 move jp,a0 56 REG_SUBU s0,a1,O32_FRAMESZ_NEW 57 REG_S sp,O32_FRAMESZ_NEW-1*SZREG(s0) 58 59 sll a0,a2,zero 60 sll a1,a3,zero 61 sll a2,a4,zero 62 sll a3,a5,zero 63 sw a6,0x10(s0) 64 sw a7,0x14(s0) 65 66 PTR_LA t0,O32_FRAMESZ(sp) 67 PTR_LA t1,0x18(s0) 68 li t2,O32_ARGC-6 691: 70 lw t3,(t0) 71 REG_ADDU t0,SZREG 72 sw t3,(t1) 73 REG_SUBU t2,1 74 REG_ADDU t1,4 75 bnez t2,1b 76 77 move sp,s0 78 79 jalr jp 80 81 REG_L sp,O32_FRAMESZ_NEW-1*SZREG(sp) 82 83 REG_L s0,O32_FRAMESZ-11*SZREG(sp) 84 REG_L s1,O32_FRAMESZ-10*SZREG(sp) 85 REG_L s2,O32_FRAMESZ-9*SZREG(sp) 86 REG_L s3,O32_FRAMESZ-8*SZREG(sp) 87 REG_L s4,O32_FRAMESZ-7*SZREG(sp) 88 REG_L s5,O32_FRAMESZ-6*SZREG(sp) 89 REG_L s6,O32_FRAMESZ-5*SZREG(sp) 90 REG_L s7,O32_FRAMESZ-4*SZREG(sp) 91 REG_L gp,O32_FRAMESZ-3*SZREG(sp) 92 REG_L fp,O32_FRAMESZ-2*SZREG(sp) 93 REG_L ra,O32_FRAMESZ-1*SZREG(sp) 94 95 REG_ADDU sp,O32_FRAMESZ 96 jr ra 97END(call_o32) 98