1/* 2 * O32 interface for the 64 (or N32) ABI. 3 * 4 * Copyright (C) 2002 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/* Maximum number of arguments supported. Must be even! */ 16#define O32_ARGC 32 17/* Number of static registers we save. */ 18#define O32_STATC 11 19/* Frame size for both of the above. */ 20#define O32_FRAMESZ (4 * O32_ARGC + SZREG * O32_STATC) 21 22 .text 23 24/* 25 * O32 function call dispatcher, for interfacing 32-bit ROM routines. 26 * 27 * The standard 64 (N32) calling sequence is supported, with a0 28 * holding a function pointer, a1-a7 -- its first seven arguments 29 * and the stack -- remaining ones (up to O32_ARGC, including a1-a7). 30 * Static registers, gp and fp are preserved, v0 holds a result. 31 * This code relies on the called o32 function for sp and ra 32 * restoration and thus both this dispatcher and the current stack 33 * have to be placed in a KSEGx (or KUSEG) address space. Any 34 * pointers passed have to point to addresses within one of these 35 * spaces as well. 36 */ 37NESTED(call_o32, O32_FRAMESZ, ra) 38 REG_SUBU sp,O32_FRAMESZ 39 40 REG_S ra,O32_FRAMESZ-1*SZREG(sp) 41 REG_S fp,O32_FRAMESZ-2*SZREG(sp) 42 REG_S gp,O32_FRAMESZ-3*SZREG(sp) 43 REG_S s7,O32_FRAMESZ-4*SZREG(sp) 44 REG_S s6,O32_FRAMESZ-5*SZREG(sp) 45 REG_S s5,O32_FRAMESZ-6*SZREG(sp) 46 REG_S s4,O32_FRAMESZ-7*SZREG(sp) 47 REG_S s3,O32_FRAMESZ-8*SZREG(sp) 48 REG_S s2,O32_FRAMESZ-9*SZREG(sp) 49 REG_S s1,O32_FRAMESZ-10*SZREG(sp) 50 REG_S s0,O32_FRAMESZ-11*SZREG(sp) 51 52 move jp,a0 53 54 sll a0,a1,zero 55 sll a1,a2,zero 56 sll a2,a3,zero 57 sll a3,a4,zero 58 sw a5,0x10(sp) 59 sw a6,0x14(sp) 60 sw a7,0x18(sp) 61 62 PTR_LA t0,O32_FRAMESZ(sp) 63 PTR_LA t1,0x1c(sp) 64 li t2,O32_ARGC-7 651: 66 lw t3,(t0) 67 REG_ADDU t0,SZREG 68 sw t3,(t1) 69 REG_SUBU t2,1 70 REG_ADDU t1,4 71 bnez t2,1b 72 73 jalr jp 74 75 REG_L s0,O32_FRAMESZ-11*SZREG(sp) 76 REG_L s1,O32_FRAMESZ-10*SZREG(sp) 77 REG_L s2,O32_FRAMESZ-9*SZREG(sp) 78 REG_L s3,O32_FRAMESZ-8*SZREG(sp) 79 REG_L s4,O32_FRAMESZ-7*SZREG(sp) 80 REG_L s5,O32_FRAMESZ-6*SZREG(sp) 81 REG_L s6,O32_FRAMESZ-5*SZREG(sp) 82 REG_L s7,O32_FRAMESZ-4*SZREG(sp) 83 REG_L gp,O32_FRAMESZ-3*SZREG(sp) 84 REG_L fp,O32_FRAMESZ-2*SZREG(sp) 85 REG_L ra,O32_FRAMESZ-1*SZREG(sp) 86 87 REG_ADDU sp,O32_FRAMESZ 88 jr ra 89END(call_o32) 90