From add34ddac7fbd4fdbfc64cc069c05e0fd273edc4 Mon Sep 17 00:00:00 2001 From: Ariadne Conill Date: Sun, 29 Mar 2020 15:54:32 +0000 Subject: [PATCH] mips: add MIPS O32 ABI implementation (closes #2) --- arch/mips/defs.h | 94 ++++++++++++++++++++++++++++++++++++ arch/mips/getcontext.S | 46 ++++++++++++++++++ arch/mips/makecontext.S | 100 +++++++++++++++++++++++++++++++++++++++ arch/mips/setcontext.S | 50 ++++++++++++++++++++ arch/mips/startcontext.S | 34 +++++++++++++ arch/mips/swapcontext.S | 81 +++++++++++++++++++++++++++++++ 6 files changed, 405 insertions(+) create mode 100644 arch/mips/defs.h create mode 100644 arch/mips/getcontext.S create mode 100644 arch/mips/makecontext.S create mode 100644 arch/mips/setcontext.S create mode 100644 arch/mips/startcontext.S create mode 100644 arch/mips/swapcontext.S diff --git a/arch/mips/defs.h b/arch/mips/defs.h new file mode 100644 index 0000000..0d605db --- /dev/null +++ b/arch/mips/defs.h @@ -0,0 +1,94 @@ +#ifndef __ARCH_MIPS64_DEFS_H +#define __ARCH_MIPS64_DEFS_H + +#define REG_SZ (4) + +#define REG_R0 (0) +#define REG_R1 (1) +#define REG_R2 (2) +#define REG_R3 (3) +#define REG_R4 (4) +#define REG_R5 (5) +#define REG_R6 (6) +#define REG_R7 (7) +#define REG_R8 (8) +#define REG_R9 (9) +#define REG_R10 (10) +#define REG_R11 (11) +#define REG_R12 (12) +#define REG_R13 (13) +#define REG_R14 (14) +#define REG_R15 (15) +#define REG_R16 (16) +#define REG_R17 (17) +#define REG_R18 (18) +#define REG_R19 (19) +#define REG_R20 (20) +#define REG_R21 (21) +#define REG_R22 (22) +#define REG_R23 (23) +#define REG_R24 (24) +#define REG_R25 (25) +#define REG_R26 (26) +#define REG_R27 (27) +#define REG_R28 (28) +#define REG_R29 (29) +#define REG_R30 (30) +#define REG_R31 (31) + +/* $a0 is $4 */ +#define REG_A0 (4) + +/* stack pointer is actually $29 */ +#define REG_SP (29) + +/* frame pointer is actually $30 */ +#define REG_FP (30) + +/* $s0 ($16) is used as link register */ +#define REG_LNK (16) + +/* $t9 ($25) is used as entry */ +#define REG_ENTRY (25) + +/* offset to mc_gregs in ucontext_t */ +#define MCONTEXT_GREGS (40) + +/* offset to PC in ucontext_t */ +#define MCONTEXT_PC (32) + +/* offset to uc_link in ucontext_t */ +#define UCONTEXT_UC_LINK (4) + +/* offset to uc_stack.ss_sp in ucontext_t */ +#define UCONTEXT_STACK_PTR (8) + +/* offset to uc_stack.ss_size in ucontext_t */ +#define UCONTEXT_STACK_SIZE (12) + +/* setup frame, from MIPS N32/N64 calling convention manual */ +#define ALSZ 15 +#define ALMASK ~15 +#define FRAMESZ (((LOCALSZ * REG_SZ) + ALSZ) & ALMASK) // 16 +#define GPOFF (FRAMESZ - (LOCALSZ * REG_SZ)) // [16 - 16] + +#define SETUP_FRAME(__proc) \ + .frame $sp, FRAMESZ, $ra; \ + .mask 0x10000000, 0; \ + .fmask 0x00000000, 0; \ + .set noreorder; \ + .cpload $25; \ + .set reorder; + +#define PUSH_FRAME(__proc) \ + addiu $sp, -FRAMESZ; \ + .cprestore GPOFF; + +#define POP_FRAME(__proc) \ + addiu $sp, FRAMESZ + +#define ENT(__proc) .ent __proc, 0; + +#include + +#endif diff --git a/arch/mips/getcontext.S b/arch/mips/getcontext.S new file mode 100644 index 0000000..ddce8ae --- /dev/null +++ b/arch/mips/getcontext.S @@ -0,0 +1,46 @@ +/* + * Copyright (c) 2020 Ariadne Conill + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * This software is provided 'as is' and without any warranty, express or + * implied. In no event shall the authors be liable for any damages arising + * from the use of this software. + */ + +LOCALSZ = 1 + +#include "defs.h" + +ALIAS(getcontext, __getcontext) + +FUNC(__getcontext) + /* copy $gp, $sp, $fp to temporary registers so we don't clobber them */ + move $a2, $gp + move $a3, $sp + move $a1, $fp + + PUSH_FRAME(__getcontext) + + /* set registers */ + sw $s0, ((16 * REG_SZ) + MCONTEXT_GREGS)($a0) + sw $s1, ((17 * REG_SZ) + MCONTEXT_GREGS)($a0) + sw $s2, ((18 * REG_SZ) + MCONTEXT_GREGS)($a0) + sw $s3, ((19 * REG_SZ) + MCONTEXT_GREGS)($a0) + sw $s4, ((20 * REG_SZ) + MCONTEXT_GREGS)($a0) + sw $s5, ((21 * REG_SZ) + MCONTEXT_GREGS)($a0) + sw $s6, ((22 * REG_SZ) + MCONTEXT_GREGS)($a0) + sw $s7, ((23 * REG_SZ) + MCONTEXT_GREGS)($a0) + + sw $a2, ((28 * REG_SZ) + MCONTEXT_GREGS)($a0) + sw $a3, ((29 * REG_SZ) + MCONTEXT_GREGS)($a0) + sw $a1, ((30 * REG_SZ) + MCONTEXT_GREGS)($a0) + sw $ra, ((31 * REG_SZ) + MCONTEXT_GREGS)($a0) + sw $ra, (MCONTEXT_PC)($a0) + + POP_FRAME(__getcontext) + + jr $ra +END(__getcontext) diff --git a/arch/mips/makecontext.S b/arch/mips/makecontext.S new file mode 100644 index 0000000..7caf39a --- /dev/null +++ b/arch/mips/makecontext.S @@ -0,0 +1,100 @@ +/* + * Copyright (c) 2020 Ariadne Conill + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * This software is provided 'as is' and without any warranty, express or + * implied. In no event shall the authors be liable for any damages arising + * from the use of this software. + */ + +LOCALSZ = 2 + +#include "defs.h" + +A3_OFF = FRAMESZ + (3 * REG_SZ) + +/* + * Because we have to fiddle with $gp, we have to implement this in + * assembly rather than C. Annoying, that... + */ + +ALIAS(makecontext, __makecontext) + +FUNC(__makecontext) + PUSH_FRAME(__makecontext) + + /* store $a3 through $a7 to the stack frame. */ + sw $a3, A3_OFF($sp) + + /* set $zero in the mcontext to 1. */ + li $v0, 1 + sw $v0, ((0 * REG_SZ) + MCONTEXT_GREGS)($a0) + + /* ensure the stack is aligned on a quad-word boundary. */ + lw $t0, UCONTEXT_STACK_PTR($a0) + lw $t2, UCONTEXT_STACK_SIZE($a0) + addiu $t1, $sp, A3_OFF + addu $t0, $t2 + and $t0, ALMASK + blez $a2, no_more_arguments + + /* store register arguments. */ + addiu $t2, $a0, MCONTEXT_GREGS + (4 * REG_SZ) + move $t3, $zero + +store_register_arg: + addiu $t3, 1 + lw $v1, ($t1) + addiu $t1, REG_SZ + sw $v1, ($t2) + addiu $t2, REG_SZ + bgeu $t3, $a2, no_more_arguments + bltu $t3, 4, store_register_arg + + /* make room for stack arguments. */ + subu $t2, $a2, $t3 + sll $t2, 3 + subu $t0, $t2 + and $t0, ALMASK + + /* store stack arguments. */ + move $t2, $t0 + +store_stack_arg: + addiu $t3, 1 + lw $v1, ($t1) + addiu $t1, REG_SZ + sw $v1, ($t2) + addiu $t2, REG_SZ + bltu $t3, $a2, store_stack_arg + +no_more_arguments: + /* make room for $a0-$a3 storage */ + addiu $t0, -(4 * REG_SZ) + + /* trampoline setup. */ + la $t9, __start_context + + /* copy link pointer as $s0... */ + lw $v1, UCONTEXT_UC_LINK($a0) + sw $v1, ((16 * REG_SZ) + MCONTEXT_GREGS)($a0) + + /* set our $sp */ + sw $t0, ((29 * REG_SZ) + MCONTEXT_GREGS)($a0) + + /* $gp is copied as $s1 */ + sw $gp, ((17 * REG_SZ) + MCONTEXT_GREGS)($a0) + + /* set our $ra */ + sw $t9, ((31 * REG_SZ) + MCONTEXT_GREGS)($a0) + + /* set our $pc */ + sw $a1, MCONTEXT_PC($a0) + + POP_FRAME(__makecontext) + + jr $ra +END(__makecontext) diff --git a/arch/mips/setcontext.S b/arch/mips/setcontext.S new file mode 100644 index 0000000..1840d88 --- /dev/null +++ b/arch/mips/setcontext.S @@ -0,0 +1,50 @@ +/* + * Copyright (c) 2020 Ariadne Conill + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * This software is provided 'as is' and without any warranty, express or + * implied. In no event shall the authors be liable for any damages arising + * from the use of this software. + */ + +LOCALSZ = 1 + +#include "defs.h" + +ALIAS(setcontext, __setcontext) + +FUNC(__setcontext) + PUSH_FRAME(__setcontext) + + /* move the context to $v0 */ + move $v0, $a0 + + /* load the registers */ + lw $a0, ((4 * REG_SZ) + MCONTEXT_GREGS)($v0) + lw $a1, ((5 * REG_SZ) + MCONTEXT_GREGS)($v0) + lw $a2, ((6 * REG_SZ) + MCONTEXT_GREGS)($v0) + lw $a3, ((7 * REG_SZ) + MCONTEXT_GREGS)($v0) + + lw $s0, ((16 * REG_SZ) + MCONTEXT_GREGS)($v0) + lw $s1, ((17 * REG_SZ) + MCONTEXT_GREGS)($v0) + lw $s2, ((18 * REG_SZ) + MCONTEXT_GREGS)($v0) + lw $s3, ((19 * REG_SZ) + MCONTEXT_GREGS)($v0) + lw $s4, ((20 * REG_SZ) + MCONTEXT_GREGS)($v0) + lw $s5, ((21 * REG_SZ) + MCONTEXT_GREGS)($v0) + lw $s6, ((22 * REG_SZ) + MCONTEXT_GREGS)($v0) + lw $s7, ((23 * REG_SZ) + MCONTEXT_GREGS)($v0) + + lw $gp, ((28 * REG_SZ) + MCONTEXT_GREGS)($v0) + lw $sp, ((29 * REG_SZ) + MCONTEXT_GREGS)($v0) + lw $fp, ((30 * REG_SZ) + MCONTEXT_GREGS)($v0) + lw $ra, ((31 * REG_SZ) + MCONTEXT_GREGS)($v0) + lw $t9, (MCONTEXT_PC)($v0) + + move $v0, $zero + jr $t9 + + POP_FRAME(__setcontext) +END(__setcontext) diff --git a/arch/mips/startcontext.S b/arch/mips/startcontext.S new file mode 100644 index 0000000..1aec638 --- /dev/null +++ b/arch/mips/startcontext.S @@ -0,0 +1,34 @@ +/* + * Copyright (c) 2020 Ariadne Conill + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * This software is provided 'as is' and without any warranty, express or + * implied. In no event shall the authors be liable for any damages arising + * from the use of this software. + */ + +LOCALSZ = 1 + +#include "defs.h" + +FUNC(__start_context) + move $gp, $s1 + + /* we receive our initial ucontext in $s0, so if $s0 is nil, bail */ + beqz $s0, no_linked_context + + /* call setcontext */ + move $a0, $s0 + la $t9, __setcontext + + jr $t9 + +no_linked_context: + move $a0, $zero + la $t9, exit + jalr $t9 + nop +END(__start_context) diff --git a/arch/mips/swapcontext.S b/arch/mips/swapcontext.S new file mode 100644 index 0000000..bfb106b --- /dev/null +++ b/arch/mips/swapcontext.S @@ -0,0 +1,81 @@ +/* + * Copyright (c) 2020 Ariadne Conill + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * This software is provided 'as is' and without any warranty, express or + * implied. In no event shall the authors be liable for any damages arising + * from the use of this software. + */ + +LOCALSZ = 2 + +#include "defs.h" + +A1_OFFSET = FRAMESZ - (1 * REG_SZ) + +ALIAS(swapcontext, __swapcontext) + +FUNC(__swapcontext) + /* copy $gp, $sp, $fp to temporary registers so we don't clobber them */ + move $a2, $gp + move $a3, $sp + + PUSH_FRAME(__swapcontext) + + /* set registers */ + sd $s0, ((16 * REG_SZ) + MCONTEXT_GREGS)($a0) + sd $s1, ((17 * REG_SZ) + MCONTEXT_GREGS)($a0) + sd $s2, ((18 * REG_SZ) + MCONTEXT_GREGS)($a0) + sd $s3, ((19 * REG_SZ) + MCONTEXT_GREGS)($a0) + sd $s4, ((20 * REG_SZ) + MCONTEXT_GREGS)($a0) + sd $s5, ((21 * REG_SZ) + MCONTEXT_GREGS)($a0) + sd $s6, ((22 * REG_SZ) + MCONTEXT_GREGS)($a0) + sd $s7, ((23 * REG_SZ) + MCONTEXT_GREGS)($a0) + + sd $a2, ((28 * REG_SZ) + MCONTEXT_GREGS)($a0) + sd $a3, ((29 * REG_SZ) + MCONTEXT_GREGS)($a0) + sd $fp, ((30 * REG_SZ) + MCONTEXT_GREGS)($a0) + sd $ra, ((31 * REG_SZ) + MCONTEXT_GREGS)($a0) + sd $ra, (MCONTEXT_PC)($a0) + + /* copy new context address in $a1 to stack */ + sd $a1, A1_OFFSET($sp) + + /* load new context address into $v0 */ + ld $v0, A1_OFFSET($sp) + + /* load the registers */ + ld $a0, ((4 * REG_SZ) + MCONTEXT_GREGS)($v0) + ld $a1, ((5 * REG_SZ) + MCONTEXT_GREGS)($v0) + ld $a2, ((6 * REG_SZ) + MCONTEXT_GREGS)($v0) + ld $a3, ((7 * REG_SZ) + MCONTEXT_GREGS)($v0) + + ld $s0, ((16 * REG_SZ) + MCONTEXT_GREGS)($v0) + ld $s1, ((17 * REG_SZ) + MCONTEXT_GREGS)($v0) + ld $s2, ((18 * REG_SZ) + MCONTEXT_GREGS)($v0) + ld $s3, ((19 * REG_SZ) + MCONTEXT_GREGS)($v0) + ld $s4, ((20 * REG_SZ) + MCONTEXT_GREGS)($v0) + ld $s5, ((21 * REG_SZ) + MCONTEXT_GREGS)($v0) + ld $s6, ((22 * REG_SZ) + MCONTEXT_GREGS)($v0) + ld $s7, ((23 * REG_SZ) + MCONTEXT_GREGS)($v0) + + ld $gp, ((28 * REG_SZ) + MCONTEXT_GREGS)($v0) + ld $sp, ((29 * REG_SZ) + MCONTEXT_GREGS)($v0) + ld $fp, ((30 * REG_SZ) + MCONTEXT_GREGS)($v0) + ld $ra, ((31 * REG_SZ) + MCONTEXT_GREGS)($v0) + ld $t9, (MCONTEXT_PC)($v0) + + move $v0, $zero + jr $t9 + +fail: + la $t9, exit + + POP_FRAME(__swapcontext) + + move $v0, $zero + jalr $t9 +END(__swapcontext)