1/* 2 * O32 interface for the 64 (or N32) ABI. 3 * 4 * Copyright (C) 2002, 2014 Maciej W. Rozycki 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 */ 11 12#include <asm/asm.h> 13#include <asm/regdef.h> 14 15/* O32 register size. */ 16#define O32_SZREG 4 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/* Argument area frame size. */ 22#define O32_ARGSZ (O32_SZREG * O32_ARGC) 23/* Static register save area frame size. */ 24#define O32_STATSZ (SZREG * O32_STATC) 25/* Stack pointer register save area frame size. */ 26#define O32_SPSZ SZREG 27/* Combined area frame size. */ 28#define O32_FRAMESZ (O32_ARGSZ + O32_SPSZ + O32_STATSZ) 29/* Switched stack frame size. */ 30#define O32_NFRAMESZ (O32_ARGSZ + O32_SPSZ) 31 32 .text 33 34/* 35 * O32 function call dispatcher, for interfacing 32-bit ROM routines. 36 * 37 * The standard 64 (N32) calling sequence is supported, with a0 holding 38 * a function pointer, a1 a pointer to the new stack to call the 39 * function with or 0 if no stack switching is requested, a2-a7 -- the 40 * function call's first six arguments, and the stack -- the remaining 41 * arguments (up to O32_ARGC, including a2-a7). Static registers, gp 42 * and fp are preserved, v0 holds the result. This code relies on the 43 * called o32 function for sp and ra restoration and this dispatcher has 44 * to be placed in a KSEGx (or KUSEG) address space. Any pointers 45 * passed have to point to addresses within one of these spaces as well. 46 */ 47NESTED(call_o32, O32_FRAMESZ, ra) 48 REG_SUBU sp,O32_FRAMESZ 49 50 REG_S ra,O32_FRAMESZ-1*SZREG(sp) 51 REG_S fp,O32_FRAMESZ-2*SZREG(sp) 52 REG_S gp,O32_FRAMESZ-3*SZREG(sp) 53 REG_S s7,O32_FRAMESZ-4*SZREG(sp) 54 REG_S s6,O32_FRAMESZ-5*SZREG(sp) 55 REG_S s5,O32_FRAMESZ-6*SZREG(sp) 56 REG_S s4,O32_FRAMESZ-7*SZREG(sp) 57 REG_S s3,O32_FRAMESZ-8*SZREG(sp) 58 REG_S s2,O32_FRAMESZ-9*SZREG(sp) 59 REG_S s1,O32_FRAMESZ-10*SZREG(sp) 60 REG_S s0,O32_FRAMESZ-11*SZREG(sp) 61 62 move jp,a0 63 64 move fp,sp 65 beqz a1,0f 66 REG_SUBU fp,a1,O32_NFRAMESZ 670: 68 REG_S sp,O32_NFRAMESZ-1*SZREG(fp) 69 70 sll a0,a2,zero 71 sll a1,a3,zero 72 sll a2,a4,zero 73 sll a3,a5,zero 74 sw a6,4*O32_SZREG(fp) 75 sw a7,5*O32_SZREG(fp) 76 77 PTR_LA t0,O32_FRAMESZ(sp) 78 PTR_LA t1,6*O32_SZREG(fp) 79 li t2,O32_ARGC-6 801: 81 lw t3,(t0) 82 REG_ADDU t0,SZREG 83 sw t3,(t1) 84 REG_SUBU t2,1 85 REG_ADDU t1,O32_SZREG 86 bnez t2,1b 87 88 move sp,fp 89 90 jalr jp 91 92 REG_L sp,O32_NFRAMESZ-1*SZREG(sp) 93 94 REG_L s0,O32_FRAMESZ-11*SZREG(sp) 95 REG_L s1,O32_FRAMESZ-10*SZREG(sp) 96 REG_L s2,O32_FRAMESZ-9*SZREG(sp) 97 REG_L s3,O32_FRAMESZ-8*SZREG(sp) 98 REG_L s4,O32_FRAMESZ-7*SZREG(sp) 99 REG_L s5,O32_FRAMESZ-6*SZREG(sp) 100 REG_L s6,O32_FRAMESZ-5*SZREG(sp) 101 REG_L s7,O32_FRAMESZ-4*SZREG(sp) 102 REG_L gp,O32_FRAMESZ-3*SZREG(sp) 103 REG_L fp,O32_FRAMESZ-2*SZREG(sp) 104 REG_L ra,O32_FRAMESZ-1*SZREG(sp) 105 106 REG_ADDU sp,O32_FRAMESZ 107 jr ra 108END(call_o32) 109