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Diffstat (limited to 'src/pkg/runtime/arm/asm.s')
| -rw-r--r-- | src/pkg/runtime/arm/asm.s | 316 |
1 files changed, 316 insertions, 0 deletions
diff --git a/src/pkg/runtime/arm/asm.s b/src/pkg/runtime/arm/asm.s new file mode 100644 index 000000000..63153658f --- /dev/null +++ b/src/pkg/runtime/arm/asm.s @@ -0,0 +1,316 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +#include "arm/asm.h" + +// using frame size $-4 means do not save LR on stack. +TEXT _rt0_arm(SB),7,$-4 + MOVW $0xcafebabe, R12 + + // copy arguments forward on an even stack + // use R13 instead of SP to avoid linker rewriting the offsets + MOVW 0(R13), R0 // argc + MOVW $4(R13), R1 // argv + SUB $64, R13 // plenty of scratch + AND $~7, R13 + MOVW R0, 60(R13) // save argc, argv away + MOVW R1, 64(R13) + + // set up m and g registers + // g is R10, m is R9 + MOVW $runtime·g0(SB), g + MOVW $runtime·m0(SB), m + + // save m->g0 = g0 + MOVW g, m_g0(m) + + // create istack out of the OS stack + MOVW $(-8192+104)(R13), R0 + MOVW R0, g_stackguard(g) // (w 104b guard) + MOVW R13, g_stackbase(g) + BL runtime·emptyfunc(SB) // fault if stack check is wrong + + BL runtime·check(SB) + + // saved argc, argv + MOVW 60(R13), R0 + MOVW R0, 4(R13) + MOVW 64(R13), R1 + MOVW R1, 8(R13) + BL runtime·args(SB) + BL runtime·osinit(SB) + BL runtime·schedinit(SB) + + // create a new goroutine to start program + MOVW $runtime·mainstart(SB), R0 + MOVW.W R0, -4(R13) + MOVW $8, R0 + MOVW.W R0, -4(R13) + MOVW $0, R0 + MOVW.W R0, -4(R13) // push $0 as guard + BL runtime·newproc(SB) + MOVW $12(R13), R13 // pop args and LR + + // start this M + BL runtime·mstart(SB) + + MOVW $1234, R0 + MOVW $1000, R1 + MOVW R0, (R1) // fail hard + B runtime·_dep_dummy(SB) // Never reached + + +TEXT runtime·mainstart(SB),7,$4 + BL main·init(SB) + BL runtime·initdone(SB) + EOR R0, R0 + MOVW R0, 0(R13) + BL main·main(SB) + MOVW $0, R0 + MOVW R0, 4(SP) + BL runtime·exit(SB) + MOVW $1234, R0 + MOVW $1001, R1 + MOVW R0, (R1) // fail hard + RET + +// TODO(kaib): remove these once i actually understand how the linker removes symbols +// pull in dummy dependencies +TEXT runtime·_dep_dummy(SB),7,$0 + BL _div(SB) + BL _divu(SB) + BL _mod(SB) + BL _modu(SB) + BL _modu(SB) + BL _sfloat(SB) + +TEXT runtime·breakpoint(SB),7,$0 + // no breakpoint yet; let program exit + RET + +/* + * go-routine + */ + +// void gosave(Gobuf*) +// save state in Gobuf; setjmp +TEXT runtime·gosave(SB), 7, $-4 + MOVW 0(FP), R0 // gobuf + MOVW SP, gobuf_sp(R0) + MOVW LR, gobuf_pc(R0) + MOVW g, gobuf_g(R0) + RET + +// void gogo(Gobuf*, uintptr) +// restore state from Gobuf; longjmp +TEXT runtime·gogo(SB), 7, $-4 + MOVW 0(FP), R1 // gobuf + MOVW 4(FP), R0 // return 2nd arg + MOVW gobuf_g(R1), g + MOVW 0(g), R2 // make sure g != nil + MOVW gobuf_sp(R1), SP // restore SP + MOVW gobuf_pc(R1), PC + +// void gogocall(Gobuf*, void (*fn)(void)) +// restore state from Gobuf but then call fn. +// (call fn, returning to state in Gobuf) +// using frame size $-4 means do not save LR on stack. +TEXT runtime·gogocall(SB), 7, $-4 + MOVW 0(FP), R0 // gobuf + MOVW 4(FP), R1 // fn + MOVW 8(FP), R2 // fp offset + MOVW gobuf_g(R0), g + MOVW 0(g), R3 // make sure g != nil + MOVW gobuf_sp(R0), SP // restore SP + MOVW gobuf_pc(R0), LR + MOVW R1, PC + +// void mcall(void (*fn)(G*)) +// Switch to m->g0's stack, call fn(g). +// Fn must never return. It should gogo(&g->sched) +// to keep running g. +TEXT runtime·mcall(SB), 7, $-4 + MOVW fn+0(FP), R0 + + // Save caller state in g->gobuf. + MOVW SP, (g_sched+gobuf_sp)(g) + MOVW LR, (g_sched+gobuf_pc)(g) + MOVW g, (g_sched+gobuf_g)(g) + + // Switch to m->g0 & its stack, call fn. + MOVW g, R1 + MOVW m_g0(m), g + CMP g, R1 + BL.EQ runtime·badmcall(SB) + MOVW (g_sched+gobuf_sp)(g), SP + SUB $8, SP + MOVW R1, 4(SP) + BL (R0) + BL runtime·badmcall2(SB) + RET + +/* + * support for morestack + */ + +// Called during function prolog when more stack is needed. +// R1 frame size +// R2 arg size +// R3 prolog's LR +// NB. we do not save R0 because we've forced 5c to pass all arguments +// on the stack. +// using frame size $-4 means do not save LR on stack. +TEXT runtime·morestack(SB),7,$-4 + // Cannot grow scheduler stack (m->g0). + MOVW m_g0(m), R4 + CMP g, R4 + BL.EQ runtime·abort(SB) + + // Save in m. + MOVW R1, m_moreframesize(m) + MOVW R2, m_moreargsize(m) + + // Called from f. + // Set m->morebuf to f's caller. + MOVW R3, (m_morebuf+gobuf_pc)(m) // f's caller's PC + MOVW SP, (m_morebuf+gobuf_sp)(m) // f's caller's SP + MOVW $4(SP), R3 // f's argument pointer + MOVW R3, m_moreargp(m) + MOVW g, (m_morebuf+gobuf_g)(m) + + // Set m->morepc to f's PC. + MOVW LR, m_morepc(m) + + // Call newstack on m->g0's stack. + MOVW m_g0(m), g + MOVW (g_sched+gobuf_sp)(g), SP + B runtime·newstack(SB) + +// Called from reflection library. Mimics morestack, +// reuses stack growth code to create a frame +// with the desired args running the desired function. +// +// func call(fn *byte, arg *byte, argsize uint32). +TEXT reflect·call(SB), 7, $-4 + // Save our caller's state as the PC and SP to + // restore when returning from f. + MOVW LR, (m_morebuf+gobuf_pc)(m) // our caller's PC + MOVW SP, (m_morebuf+gobuf_sp)(m) // our caller's SP + MOVW g, (m_morebuf+gobuf_g)(m) + + // Set up morestack arguments to call f on a new stack. + // We set f's frame size to 1, as a hint to newstack + // that this is a call from reflect·call. + // If it turns out that f needs a larger frame than + // the default stack, f's usual stack growth prolog will + // allocate a new segment (and recopy the arguments). + MOVW 4(SP), R0 // fn + MOVW 8(SP), R1 // arg frame + MOVW 12(SP), R2 // arg size + + MOVW R0, m_morepc(m) // f's PC + MOVW R1, m_moreargp(m) // f's argument pointer + MOVW R2, m_moreargsize(m) // f's argument size + MOVW $1, R3 + MOVW R3, m_moreframesize(m) // f's frame size + + // Call newstack on m->g0's stack. + MOVW m_g0(m), g + MOVW (g_sched+gobuf_sp)(g), SP + B runtime·newstack(SB) + +// Return point when leaving stack. +// using frame size $-4 means do not save LR on stack. +TEXT runtime·lessstack(SB), 7, $-4 + // Save return value in m->cret + MOVW R0, m_cret(m) + + // Call oldstack on m->g0's stack. + MOVW m_g0(m), g + MOVW (g_sched+gobuf_sp)(g), SP + B runtime·oldstack(SB) + +// void jmpdefer(fn, sp); +// called from deferreturn. +// 1. grab stored LR for caller +// 2. sub 4 bytes to get back to BL deferreturn +// 3. B to fn +TEXT runtime·jmpdefer(SB), 7, $0 + MOVW 0(SP), LR + MOVW $-4(LR), LR // BL deferreturn + MOVW fn+0(FP), R0 + MOVW argp+4(FP), SP + MOVW $-4(SP), SP // SP is 4 below argp, due to saved LR + B (R0) + +TEXT runtime·asmcgocall(SB),7,$0 + B runtime·cgounimpl(SB) + +TEXT runtime·cgocallback(SB),7,$0 + B runtime·cgounimpl(SB) + +TEXT runtime·memclr(SB),7,$20 + MOVW 0(FP), R0 + MOVW $0, R1 // c = 0 + MOVW R1, -16(SP) + MOVW 4(FP), R1 // n + MOVW R1, -12(SP) + MOVW m, -8(SP) // Save m and g + MOVW g, -4(SP) + BL runtime·memset(SB) + MOVW -8(SP), m // Restore m and g, memset clobbers them + MOVW -4(SP), g + RET + +TEXT runtime·getcallerpc(SB),7,$-4 + MOVW 0(SP), R0 + RET + +TEXT runtime·setcallerpc(SB),7,$-4 + MOVW x+4(FP), R0 + MOVW R0, 0(SP) + RET + +TEXT runtime·getcallersp(SB),7,$-4 + MOVW 0(FP), R0 + MOVW $-4(R0), R0 + RET + +TEXT runtime·emptyfunc(SB),0,$0 + RET + +TEXT runtime·abort(SB),7,$-4 + MOVW $0, R0 + MOVW (R0), R1 + +// bool armcas(int32 *val, int32 old, int32 new) +// Atomically: +// if(*val == old){ +// *val = new; +// return 1; +// }else +// return 0; +// +// To implement runtime·cas in ../$GOOS/arm/sys.s +// using the native instructions, use: +// +// TEXT runtime·cas(SB),7,$0 +// B runtime·armcas(SB) +// +TEXT runtime·armcas(SB),7,$0 + MOVW valptr+0(FP), R1 + MOVW old+4(FP), R2 + MOVW new+8(FP), R3 +casl: + LDREX (R1), R0 + CMP R0, R2 + BNE casfail + STREX R3, (R1), R0 + CMP $0, R0 + BNE casl + MOVW $1, R0 + RET +casfail: + MOVW $0, R0 + RET |