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diff --git a/src/runtime/asm_arm.s b/src/runtime/asm_arm.s
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+// 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 "go_asm.h"
+#include "go_tls.h"
+#include "funcdata.h"
+#include "textflag.h"
+
+// _rt0_arm is common startup code for most ARM systems when using
+// internal linking. This is the entry point for the program from the
+// kernel for an ordinary -buildmode=exe program. The stack holds the
+// number of arguments and the C-style argv.
+TEXT _rt0_arm(SB),NOSPLIT|NOFRAME,$0
+ MOVW (R13), R0 // argc
+ MOVW $4(R13), R1 // argv
+ B runtime·rt0_go(SB)
+
+// main is common startup code for most ARM systems when using
+// external linking. The C startup code will call the symbol "main"
+// passing argc and argv in the usual C ABI registers R0 and R1.
+TEXT main(SB),NOSPLIT|NOFRAME,$0
+ B runtime·rt0_go(SB)
+
+// _rt0_arm_lib is common startup code for most ARM systems when
+// using -buildmode=c-archive or -buildmode=c-shared. The linker will
+// arrange to invoke this function as a global constructor (for
+// c-archive) or when the shared library is loaded (for c-shared).
+// We expect argc and argv to be passed in the usual C ABI registers
+// R0 and R1.
+TEXT _rt0_arm_lib(SB),NOSPLIT,$104
+ // Preserve callee-save registers. Raspberry Pi's dlopen(), for example,
+ // actually cares that R11 is preserved.
+ MOVW R4, 12(R13)
+ MOVW R5, 16(R13)
+ MOVW R6, 20(R13)
+ MOVW R7, 24(R13)
+ MOVW R8, 28(R13)
+ MOVW g, 32(R13)
+ MOVW R11, 36(R13)
+
+ // Skip floating point registers on GOARM < 6.
+ MOVB runtime·goarm(SB), R11
+ CMP $6, R11
+ BLT skipfpsave
+ MOVD F8, (40+8*0)(R13)
+ MOVD F9, (40+8*1)(R13)
+ MOVD F10, (40+8*2)(R13)
+ MOVD F11, (40+8*3)(R13)
+ MOVD F12, (40+8*4)(R13)
+ MOVD F13, (40+8*5)(R13)
+ MOVD F14, (40+8*6)(R13)
+ MOVD F15, (40+8*7)(R13)
+skipfpsave:
+ // Save argc/argv.
+ MOVW R0, _rt0_arm_lib_argc<>(SB)
+ MOVW R1, _rt0_arm_lib_argv<>(SB)
+
+ MOVW $0, g // Initialize g.
+
+ // Synchronous initialization.
+ CALL runtime·libpreinit(SB)
+
+ // Create a new thread to do the runtime initialization.
+ MOVW _cgo_sys_thread_create(SB), R2
+ CMP $0, R2
+ BEQ nocgo
+ MOVW $_rt0_arm_lib_go<>(SB), R0
+ MOVW $0, R1
+ BL (R2)
+ B rr
+nocgo:
+ MOVW $0x800000, R0 // stacksize = 8192KB
+ MOVW $_rt0_arm_lib_go<>(SB), R1 // fn
+ MOVW R0, 4(R13)
+ MOVW R1, 8(R13)
+ BL runtime·newosproc0(SB)
+rr:
+ // Restore callee-save registers and return.
+ MOVB runtime·goarm(SB), R11
+ CMP $6, R11
+ BLT skipfprest
+ MOVD (40+8*0)(R13), F8
+ MOVD (40+8*1)(R13), F9
+ MOVD (40+8*2)(R13), F10
+ MOVD (40+8*3)(R13), F11
+ MOVD (40+8*4)(R13), F12
+ MOVD (40+8*5)(R13), F13
+ MOVD (40+8*6)(R13), F14
+ MOVD (40+8*7)(R13), F15
+skipfprest:
+ MOVW 12(R13), R4
+ MOVW 16(R13), R5
+ MOVW 20(R13), R6
+ MOVW 24(R13), R7
+ MOVW 28(R13), R8
+ MOVW 32(R13), g
+ MOVW 36(R13), R11
+ RET
+
+// _rt0_arm_lib_go initializes the Go runtime.
+// This is started in a separate thread by _rt0_arm_lib.
+TEXT _rt0_arm_lib_go<>(SB),NOSPLIT,$8
+ MOVW _rt0_arm_lib_argc<>(SB), R0
+ MOVW _rt0_arm_lib_argv<>(SB), R1
+ B runtime·rt0_go(SB)
+
+DATA _rt0_arm_lib_argc<>(SB)/4,$0
+GLOBL _rt0_arm_lib_argc<>(SB),NOPTR,$4
+DATA _rt0_arm_lib_argv<>(SB)/4,$0
+GLOBL _rt0_arm_lib_argv<>(SB),NOPTR,$4
+
+// using NOFRAME means do not save LR on stack.
+// argc is in R0, argv is in R1.
+TEXT runtime·rt0_go(SB),NOSPLIT|NOFRAME|TOPFRAME,$0
+ MOVW $0xcafebabe, R12
+
+ // copy arguments forward on an even stack
+ // use R13 instead of SP to avoid linker rewriting the offsets
+ SUB $64, R13 // plenty of scratch
+ AND $~7, R13
+ MOVW R0, 60(R13) // save argc, argv away
+ MOVW R1, 64(R13)
+
+ // set up g register
+ // g is R10
+ MOVW $runtime·g0(SB), g
+ MOVW $runtime·m0(SB), R8
+
+ // save m->g0 = g0
+ MOVW g, m_g0(R8)
+ // save g->m = m0
+ MOVW R8, g_m(g)
+
+ // create istack out of the OS stack
+ // (1MB of system stack is available on iOS and Android)
+ MOVW $(-64*1024+104)(R13), R0
+ MOVW R0, g_stackguard0(g)
+ MOVW R0, g_stackguard1(g)
+ MOVW R0, (g_stack+stack_lo)(g)
+ MOVW R13, (g_stack+stack_hi)(g)
+
+ BL runtime·emptyfunc(SB) // fault if stack check is wrong
+
+#ifdef GOOS_openbsd
+ // Save g to TLS so that it is available from signal trampoline.
+ BL runtime·save_g(SB)
+#endif
+
+ BL runtime·_initcgo(SB) // will clobber R0-R3
+
+ // update stackguard after _cgo_init
+ MOVW (g_stack+stack_lo)(g), R0
+ ADD $const__StackGuard, R0
+ MOVW R0, g_stackguard0(g)
+ MOVW R0, g_stackguard1(g)
+
+ 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·checkgoarm(SB)
+ BL runtime·osinit(SB)
+ BL runtime·schedinit(SB)
+
+ // create a new goroutine to start program
+ SUB $8, R13
+ MOVW $runtime·mainPC(SB), R0
+ MOVW R0, 4(R13) // arg 1: fn
+ MOVW $0, R0
+ MOVW R0, 0(R13) // dummy LR
+ BL runtime·newproc(SB)
+ ADD $8, R13 // pop args and LR
+
+ // start this M
+ BL runtime·mstart(SB)
+
+ MOVW $1234, R0
+ MOVW $1000, R1
+ MOVW R0, (R1) // fail hard
+
+DATA runtime·mainPC+0(SB)/4,$runtime·main(SB)
+GLOBL runtime·mainPC(SB),RODATA,$4
+
+TEXT runtime·breakpoint(SB),NOSPLIT,$0-0
+ // gdb won't skip this breakpoint instruction automatically,
+ // so you must manually "set $pc+=4" to skip it and continue.
+#ifdef GOOS_plan9
+ WORD $0xD1200070 // undefined instruction used as armv5 breakpoint in Plan 9
+#else
+ WORD $0xe7f001f0 // undefined instruction that gdb understands is a software breakpoint
+#endif
+ RET
+
+TEXT runtime·asminit(SB),NOSPLIT,$0-0
+ // disable runfast (flush-to-zero) mode of vfp if runtime.goarm > 5
+ MOVB runtime·goarm(SB), R11
+ CMP $5, R11
+ BLE 4(PC)
+ WORD $0xeef1ba10 // vmrs r11, fpscr
+ BIC $(1<<24), R11
+ WORD $0xeee1ba10 // vmsr fpscr, r11
+ RET
+
+TEXT runtime·mstart(SB),NOSPLIT|TOPFRAME,$0
+ BL runtime·mstart0(SB)
+ RET // not reached
+
+/*
+ * go-routine
+ */
+
+// void gogo(Gobuf*)
+// restore state from Gobuf; longjmp
+TEXT runtime·gogo(SB),NOSPLIT|NOFRAME,$0-4
+ MOVW buf+0(FP), R1
+ MOVW gobuf_g(R1), R0
+ MOVW 0(R0), R2 // make sure g != nil
+ B gogo<>(SB)
+
+TEXT gogo<>(SB),NOSPLIT|NOFRAME,$0
+ BL setg<>(SB)
+ MOVW gobuf_sp(R1), R13 // restore SP==R13
+ MOVW gobuf_lr(R1), LR
+ MOVW gobuf_ret(R1), R0
+ MOVW gobuf_ctxt(R1), R7
+ MOVW $0, R11
+ MOVW R11, gobuf_sp(R1) // clear to help garbage collector
+ MOVW R11, gobuf_ret(R1)
+ MOVW R11, gobuf_lr(R1)
+ MOVW R11, gobuf_ctxt(R1)
+ MOVW gobuf_pc(R1), R11
+ CMP R11, R11 // set condition codes for == test, needed by stack split
+ B (R11)
+
+// func mcall(fn func(*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),NOSPLIT|NOFRAME,$0-4
+ // Save caller state in g->sched.
+ MOVW R13, (g_sched+gobuf_sp)(g)
+ MOVW LR, (g_sched+gobuf_pc)(g)
+ MOVW $0, R11
+ MOVW R11, (g_sched+gobuf_lr)(g)
+
+ // Switch to m->g0 & its stack, call fn.
+ MOVW g, R1
+ MOVW g_m(g), R8
+ MOVW m_g0(R8), R0
+ BL setg<>(SB)
+ CMP g, R1
+ B.NE 2(PC)
+ B runtime·badmcall(SB)
+ MOVW fn+0(FP), R0
+ MOVW (g_sched+gobuf_sp)(g), R13
+ SUB $8, R13
+ MOVW R1, 4(R13)
+ MOVW R0, R7
+ MOVW 0(R0), R0
+ BL (R0)
+ B runtime·badmcall2(SB)
+ RET
+
+// systemstack_switch is a dummy routine that systemstack leaves at the bottom
+// of the G stack. We need to distinguish the routine that
+// lives at the bottom of the G stack from the one that lives
+// at the top of the system stack because the one at the top of
+// the system stack terminates the stack walk (see topofstack()).
+TEXT runtime·systemstack_switch(SB),NOSPLIT,$0-0
+ MOVW $0, R0
+ BL (R0) // clobber lr to ensure push {lr} is kept
+ RET
+
+// func systemstack(fn func())
+TEXT runtime·systemstack(SB),NOSPLIT,$0-4
+ MOVW fn+0(FP), R0 // R0 = fn
+ MOVW g_m(g), R1 // R1 = m
+
+ MOVW m_gsignal(R1), R2 // R2 = gsignal
+ CMP g, R2
+ B.EQ noswitch
+
+ MOVW m_g0(R1), R2 // R2 = g0
+ CMP g, R2
+ B.EQ noswitch
+
+ MOVW m_curg(R1), R3
+ CMP g, R3
+ B.EQ switch
+
+ // Bad: g is not gsignal, not g0, not curg. What is it?
+ // Hide call from linker nosplit analysis.
+ MOVW $runtime·badsystemstack(SB), R0
+ BL (R0)
+ B runtime·abort(SB)
+
+switch:
+ // save our state in g->sched. Pretend to
+ // be systemstack_switch if the G stack is scanned.
+ BL gosave_systemstack_switch<>(SB)
+
+ // switch to g0
+ MOVW R0, R5
+ MOVW R2, R0
+ BL setg<>(SB)
+ MOVW R5, R0
+ MOVW (g_sched+gobuf_sp)(R2), R13
+
+ // call target function
+ MOVW R0, R7
+ MOVW 0(R0), R0
+ BL (R0)
+
+ // switch back to g
+ MOVW g_m(g), R1
+ MOVW m_curg(R1), R0
+ BL setg<>(SB)
+ MOVW (g_sched+gobuf_sp)(g), R13
+ MOVW $0, R3
+ MOVW R3, (g_sched+gobuf_sp)(g)
+ RET
+
+noswitch:
+ // Using a tail call here cleans up tracebacks since we won't stop
+ // at an intermediate systemstack.
+ MOVW R0, R7
+ MOVW 0(R0), R0
+ MOVW.P 4(R13), R14 // restore LR
+ B (R0)
+
+/*
+ * support for morestack
+ */
+
+// Called during function prolog when more stack is needed.
+// R3 prolog's LR
+// using NOFRAME means do not save LR on stack.
+//
+// The traceback routines see morestack on a g0 as being
+// the top of a stack (for example, morestack calling newstack
+// calling the scheduler calling newm calling gc), so we must
+// record an argument size. For that purpose, it has no arguments.
+TEXT runtime·morestack(SB),NOSPLIT|NOFRAME,$0-0
+ // Cannot grow scheduler stack (m->g0).
+ MOVW g_m(g), R8
+ MOVW m_g0(R8), R4
+ CMP g, R4
+ BNE 3(PC)
+ BL runtime·badmorestackg0(SB)
+ B runtime·abort(SB)
+
+ // Cannot grow signal stack (m->gsignal).
+ MOVW m_gsignal(R8), R4
+ CMP g, R4
+ BNE 3(PC)
+ BL runtime·badmorestackgsignal(SB)
+ B runtime·abort(SB)
+
+ // Called from f.
+ // Set g->sched to context in f.
+ MOVW R13, (g_sched+gobuf_sp)(g)
+ MOVW LR, (g_sched+gobuf_pc)(g)
+ MOVW R3, (g_sched+gobuf_lr)(g)
+ MOVW R7, (g_sched+gobuf_ctxt)(g)
+
+ // Called from f.
+ // Set m->morebuf to f's caller.
+ MOVW R3, (m_morebuf+gobuf_pc)(R8) // f's caller's PC
+ MOVW R13, (m_morebuf+gobuf_sp)(R8) // f's caller's SP
+ MOVW g, (m_morebuf+gobuf_g)(R8)
+
+ // Call newstack on m->g0's stack.
+ MOVW m_g0(R8), R0
+ BL setg<>(SB)
+ MOVW (g_sched+gobuf_sp)(g), R13
+ MOVW $0, R0
+ MOVW.W R0, -4(R13) // create a call frame on g0 (saved LR)
+ BL runtime·newstack(SB)
+
+ // Not reached, but make sure the return PC from the call to newstack
+ // is still in this function, and not the beginning of the next.
+ RET
+
+TEXT runtime·morestack_noctxt(SB),NOSPLIT|NOFRAME,$0-0
+ // Force SPWRITE. This function doesn't actually write SP,
+ // but it is called with a special calling convention where
+ // the caller doesn't save LR on stack but passes it as a
+ // register (R3), and the unwinder currently doesn't understand.
+ // Make it SPWRITE to stop unwinding. (See issue 54332)
+ MOVW R13, R13
+
+ MOVW $0, R7
+ B runtime·morestack(SB)
+
+// reflectcall: call a function with the given argument list
+// func call(stackArgsType *_type, f *FuncVal, stackArgs *byte, stackArgsSize, stackRetOffset, frameSize uint32, regArgs *abi.RegArgs).
+// we don't have variable-sized frames, so we use a small number
+// of constant-sized-frame functions to encode a few bits of size in the pc.
+// Caution: ugly multiline assembly macros in your future!
+
+#define DISPATCH(NAME,MAXSIZE) \
+ CMP $MAXSIZE, R0; \
+ B.HI 3(PC); \
+ MOVW $NAME(SB), R1; \
+ B (R1)
+
+TEXT ·reflectcall(SB),NOSPLIT|NOFRAME,$0-28
+ MOVW frameSize+20(FP), R0
+ DISPATCH(runtime·call16, 16)
+ DISPATCH(runtime·call32, 32)
+ DISPATCH(runtime·call64, 64)
+ DISPATCH(runtime·call128, 128)
+ DISPATCH(runtime·call256, 256)
+ DISPATCH(runtime·call512, 512)
+ DISPATCH(runtime·call1024, 1024)
+ DISPATCH(runtime·call2048, 2048)
+ DISPATCH(runtime·call4096, 4096)
+ DISPATCH(runtime·call8192, 8192)
+ DISPATCH(runtime·call16384, 16384)
+ DISPATCH(runtime·call32768, 32768)
+ DISPATCH(runtime·call65536, 65536)
+ DISPATCH(runtime·call131072, 131072)
+ DISPATCH(runtime·call262144, 262144)
+ DISPATCH(runtime·call524288, 524288)
+ DISPATCH(runtime·call1048576, 1048576)
+ DISPATCH(runtime·call2097152, 2097152)
+ DISPATCH(runtime·call4194304, 4194304)
+ DISPATCH(runtime·call8388608, 8388608)
+ DISPATCH(runtime·call16777216, 16777216)
+ DISPATCH(runtime·call33554432, 33554432)
+ DISPATCH(runtime·call67108864, 67108864)
+ DISPATCH(runtime·call134217728, 134217728)
+ DISPATCH(runtime·call268435456, 268435456)
+ DISPATCH(runtime·call536870912, 536870912)
+ DISPATCH(runtime·call1073741824, 1073741824)
+ MOVW $runtime·badreflectcall(SB), R1
+ B (R1)
+
+#define CALLFN(NAME,MAXSIZE) \
+TEXT NAME(SB), WRAPPER, $MAXSIZE-28; \
+ NO_LOCAL_POINTERS; \
+ /* copy arguments to stack */ \
+ MOVW stackArgs+8(FP), R0; \
+ MOVW stackArgsSize+12(FP), R2; \
+ ADD $4, R13, R1; \
+ CMP $0, R2; \
+ B.EQ 5(PC); \
+ MOVBU.P 1(R0), R5; \
+ MOVBU.P R5, 1(R1); \
+ SUB $1, R2, R2; \
+ B -5(PC); \
+ /* call function */ \
+ MOVW f+4(FP), R7; \
+ MOVW (R7), R0; \
+ PCDATA $PCDATA_StackMapIndex, $0; \
+ BL (R0); \
+ /* copy return values back */ \
+ MOVW stackArgsType+0(FP), R4; \
+ MOVW stackArgs+8(FP), R0; \
+ MOVW stackArgsSize+12(FP), R2; \
+ MOVW stackArgsRetOffset+16(FP), R3; \
+ ADD $4, R13, R1; \
+ ADD R3, R1; \
+ ADD R3, R0; \
+ SUB R3, R2; \
+ BL callRet<>(SB); \
+ RET
+
+// callRet copies return values back at the end of call*. This is a
+// separate function so it can allocate stack space for the arguments
+// to reflectcallmove. It does not follow the Go ABI; it expects its
+// arguments in registers.
+TEXT callRet<>(SB), NOSPLIT, $20-0
+ MOVW R4, 4(R13)
+ MOVW R0, 8(R13)
+ MOVW R1, 12(R13)
+ MOVW R2, 16(R13)
+ MOVW $0, R7
+ MOVW R7, 20(R13)
+ BL runtime·reflectcallmove(SB)
+ RET
+
+CALLFN(·call16, 16)
+CALLFN(·call32, 32)
+CALLFN(·call64, 64)
+CALLFN(·call128, 128)
+CALLFN(·call256, 256)
+CALLFN(·call512, 512)
+CALLFN(·call1024, 1024)
+CALLFN(·call2048, 2048)
+CALLFN(·call4096, 4096)
+CALLFN(·call8192, 8192)
+CALLFN(·call16384, 16384)
+CALLFN(·call32768, 32768)
+CALLFN(·call65536, 65536)
+CALLFN(·call131072, 131072)
+CALLFN(·call262144, 262144)
+CALLFN(·call524288, 524288)
+CALLFN(·call1048576, 1048576)
+CALLFN(·call2097152, 2097152)
+CALLFN(·call4194304, 4194304)
+CALLFN(·call8388608, 8388608)
+CALLFN(·call16777216, 16777216)
+CALLFN(·call33554432, 33554432)
+CALLFN(·call67108864, 67108864)
+CALLFN(·call134217728, 134217728)
+CALLFN(·call268435456, 268435456)
+CALLFN(·call536870912, 536870912)
+CALLFN(·call1073741824, 1073741824)
+
+// Save state of caller into g->sched,
+// but using fake PC from systemstack_switch.
+// Must only be called from functions with no locals ($0)
+// or else unwinding from systemstack_switch is incorrect.
+// Smashes R11.
+TEXT gosave_systemstack_switch<>(SB),NOSPLIT|NOFRAME,$0
+ MOVW $runtime·systemstack_switch(SB), R11
+ ADD $4, R11 // get past push {lr}
+ MOVW R11, (g_sched+gobuf_pc)(g)
+ MOVW R13, (g_sched+gobuf_sp)(g)
+ MOVW $0, R11
+ MOVW R11, (g_sched+gobuf_lr)(g)
+ MOVW R11, (g_sched+gobuf_ret)(g)
+ // Assert ctxt is zero. See func save.
+ MOVW (g_sched+gobuf_ctxt)(g), R11
+ TST R11, R11
+ B.EQ 2(PC)
+ BL runtime·abort(SB)
+ RET
+
+// func asmcgocall_no_g(fn, arg unsafe.Pointer)
+// Call fn(arg) aligned appropriately for the gcc ABI.
+// Called on a system stack, and there may be no g yet (during needm).
+TEXT ·asmcgocall_no_g(SB),NOSPLIT,$0-8
+ MOVW fn+0(FP), R1
+ MOVW arg+4(FP), R0
+ MOVW R13, R2
+ SUB $32, R13
+ BIC $0x7, R13 // alignment for gcc ABI
+ MOVW R2, 8(R13)
+ BL (R1)
+ MOVW 8(R13), R2
+ MOVW R2, R13
+ RET
+
+// func asmcgocall(fn, arg unsafe.Pointer) int32
+// Call fn(arg) on the scheduler stack,
+// aligned appropriately for the gcc ABI.
+// See cgocall.go for more details.
+TEXT ·asmcgocall(SB),NOSPLIT,$0-12
+ MOVW fn+0(FP), R1
+ MOVW arg+4(FP), R0
+
+ MOVW R13, R2
+ CMP $0, g
+ BEQ nosave
+ MOVW g, R4
+
+ // Figure out if we need to switch to m->g0 stack.
+ // We get called to create new OS threads too, and those
+ // come in on the m->g0 stack already. Or we might already
+ // be on the m->gsignal stack.
+ MOVW g_m(g), R8
+ MOVW m_gsignal(R8), R3
+ CMP R3, g
+ BEQ nosave
+ MOVW m_g0(R8), R3
+ CMP R3, g
+ BEQ nosave
+ BL gosave_systemstack_switch<>(SB)
+ MOVW R0, R5
+ MOVW R3, R0
+ BL setg<>(SB)
+ MOVW R5, R0
+ MOVW (g_sched+gobuf_sp)(g), R13
+
+ // Now on a scheduling stack (a pthread-created stack).
+ SUB $24, R13
+ BIC $0x7, R13 // alignment for gcc ABI
+ MOVW R4, 20(R13) // save old g
+ MOVW (g_stack+stack_hi)(R4), R4
+ SUB R2, R4
+ MOVW R4, 16(R13) // save depth in stack (can't just save SP, as stack might be copied during a callback)
+ BL (R1)
+
+ // Restore registers, g, stack pointer.
+ MOVW R0, R5
+ MOVW 20(R13), R0
+ BL setg<>(SB)
+ MOVW (g_stack+stack_hi)(g), R1
+ MOVW 16(R13), R2
+ SUB R2, R1
+ MOVW R5, R0
+ MOVW R1, R13
+
+ MOVW R0, ret+8(FP)
+ RET
+
+nosave:
+ // Running on a system stack, perhaps even without a g.
+ // Having no g can happen during thread creation or thread teardown
+ // (see needm/dropm on Solaris, for example).
+ // This code is like the above sequence but without saving/restoring g
+ // and without worrying about the stack moving out from under us
+ // (because we're on a system stack, not a goroutine stack).
+ // The above code could be used directly if already on a system stack,
+ // but then the only path through this code would be a rare case on Solaris.
+ // Using this code for all "already on system stack" calls exercises it more,
+ // which should help keep it correct.
+ SUB $24, R13
+ BIC $0x7, R13 // alignment for gcc ABI
+ // save null g in case someone looks during debugging.
+ MOVW $0, R4
+ MOVW R4, 20(R13)
+ MOVW R2, 16(R13) // Save old stack pointer.
+ BL (R1)
+ // Restore stack pointer.
+ MOVW 16(R13), R2
+ MOVW R2, R13
+ MOVW R0, ret+8(FP)
+ RET
+
+// cgocallback(fn, frame unsafe.Pointer, ctxt uintptr)
+// See cgocall.go for more details.
+TEXT ·cgocallback(SB),NOSPLIT,$12-12
+ NO_LOCAL_POINTERS
+
+ // Load m and g from thread-local storage.
+#ifdef GOOS_openbsd
+ BL runtime·load_g(SB)
+#else
+ MOVB runtime·iscgo(SB), R0
+ CMP $0, R0
+ BL.NE runtime·load_g(SB)
+#endif
+
+ // If g is nil, Go did not create the current thread.
+ // Call needm to obtain one for temporary use.
+ // In this case, we're running on the thread stack, so there's
+ // lots of space, but the linker doesn't know. Hide the call from
+ // the linker analysis by using an indirect call.
+ CMP $0, g
+ B.EQ needm
+
+ MOVW g_m(g), R8
+ MOVW R8, savedm-4(SP)
+ B havem
+
+needm:
+ MOVW g, savedm-4(SP) // g is zero, so is m.
+ MOVW $runtime·needm(SB), R0
+ BL (R0)
+
+ // Set m->g0->sched.sp = SP, so that if a panic happens
+ // during the function we are about to execute, it will
+ // have a valid SP to run on the g0 stack.
+ // The next few lines (after the havem label)
+ // will save this SP onto the stack and then write
+ // the same SP back to m->sched.sp. That seems redundant,
+ // but if an unrecovered panic happens, unwindm will
+ // restore the g->sched.sp from the stack location
+ // and then systemstack will try to use it. If we don't set it here,
+ // that restored SP will be uninitialized (typically 0) and
+ // will not be usable.
+ MOVW g_m(g), R8
+ MOVW m_g0(R8), R3
+ MOVW R13, (g_sched+gobuf_sp)(R3)
+
+havem:
+ // Now there's a valid m, and we're running on its m->g0.
+ // Save current m->g0->sched.sp on stack and then set it to SP.
+ // Save current sp in m->g0->sched.sp in preparation for
+ // switch back to m->curg stack.
+ // NOTE: unwindm knows that the saved g->sched.sp is at 4(R13) aka savedsp-12(SP).
+ MOVW m_g0(R8), R3
+ MOVW (g_sched+gobuf_sp)(R3), R4
+ MOVW R4, savedsp-12(SP) // must match frame size
+ MOVW R13, (g_sched+gobuf_sp)(R3)
+
+ // Switch to m->curg stack and call runtime.cgocallbackg.
+ // Because we are taking over the execution of m->curg
+ // but *not* resuming what had been running, we need to
+ // save that information (m->curg->sched) so we can restore it.
+ // We can restore m->curg->sched.sp easily, because calling
+ // runtime.cgocallbackg leaves SP unchanged upon return.
+ // To save m->curg->sched.pc, we push it onto the curg stack and
+ // open a frame the same size as cgocallback's g0 frame.
+ // Once we switch to the curg stack, the pushed PC will appear
+ // to be the return PC of cgocallback, so that the traceback
+ // will seamlessly trace back into the earlier calls.
+ MOVW m_curg(R8), R0
+ BL setg<>(SB)
+ MOVW (g_sched+gobuf_sp)(g), R4 // prepare stack as R4
+ MOVW (g_sched+gobuf_pc)(g), R5
+ MOVW R5, -(12+4)(R4) // "saved LR"; must match frame size
+ // Gather our arguments into registers.
+ MOVW fn+0(FP), R1
+ MOVW frame+4(FP), R2
+ MOVW ctxt+8(FP), R3
+ MOVW $-(12+4)(R4), R13 // switch stack; must match frame size
+ MOVW R1, 4(R13)
+ MOVW R2, 8(R13)
+ MOVW R3, 12(R13)
+ BL runtime·cgocallbackg(SB)
+
+ // Restore g->sched (== m->curg->sched) from saved values.
+ MOVW 0(R13), R5
+ MOVW R5, (g_sched+gobuf_pc)(g)
+ MOVW $(12+4)(R13), R4 // must match frame size
+ MOVW R4, (g_sched+gobuf_sp)(g)
+
+ // Switch back to m->g0's stack and restore m->g0->sched.sp.
+ // (Unlike m->curg, the g0 goroutine never uses sched.pc,
+ // so we do not have to restore it.)
+ MOVW g_m(g), R8
+ MOVW m_g0(R8), R0
+ BL setg<>(SB)
+ MOVW (g_sched+gobuf_sp)(g), R13
+ MOVW savedsp-12(SP), R4 // must match frame size
+ MOVW R4, (g_sched+gobuf_sp)(g)
+
+ // If the m on entry was nil, we called needm above to borrow an m
+ // for the duration of the call. Since the call is over, return it with dropm.
+ MOVW savedm-4(SP), R6
+ CMP $0, R6
+ B.NE 3(PC)
+ MOVW $runtime·dropm(SB), R0
+ BL (R0)
+
+ // Done!
+ RET
+
+// void setg(G*); set g. for use by needm.
+TEXT runtime·setg(SB),NOSPLIT|NOFRAME,$0-4
+ MOVW gg+0(FP), R0
+ B setg<>(SB)
+
+TEXT setg<>(SB),NOSPLIT|NOFRAME,$0-0
+ MOVW R0, g
+
+ // Save g to thread-local storage.
+#ifdef GOOS_windows
+ B runtime·save_g(SB)
+#else
+#ifdef GOOS_openbsd
+ B runtime·save_g(SB)
+#else
+ MOVB runtime·iscgo(SB), R0
+ CMP $0, R0
+ B.EQ 2(PC)
+ B runtime·save_g(SB)
+
+ MOVW g, R0
+ RET
+#endif
+#endif
+
+TEXT runtime·emptyfunc(SB),0,$0-0
+ RET
+
+TEXT runtime·abort(SB),NOSPLIT|NOFRAME,$0-0
+ MOVW $0, R0
+ MOVW (R0), R1
+
+// armPublicationBarrier is a native store/store barrier for ARMv7+.
+// On earlier ARM revisions, armPublicationBarrier is a no-op.
+// This will not work on SMP ARMv6 machines, if any are in use.
+// To implement publicationBarrier in sys_$GOOS_arm.s using the native
+// instructions, use:
+//
+// TEXT ·publicationBarrier(SB),NOSPLIT|NOFRAME,$0-0
+// B runtime·armPublicationBarrier(SB)
+//
+TEXT runtime·armPublicationBarrier(SB),NOSPLIT|NOFRAME,$0-0
+ MOVB runtime·goarm(SB), R11
+ CMP $7, R11
+ BLT 2(PC)
+ DMB MB_ST
+ RET
+
+// AES hashing not implemented for ARM
+TEXT runtime·memhash(SB),NOSPLIT|NOFRAME,$0-16
+ JMP runtime·memhashFallback(SB)
+TEXT runtime·strhash(SB),NOSPLIT|NOFRAME,$0-12
+ JMP runtime·strhashFallback(SB)
+TEXT runtime·memhash32(SB),NOSPLIT|NOFRAME,$0-12
+ JMP runtime·memhash32Fallback(SB)
+TEXT runtime·memhash64(SB),NOSPLIT|NOFRAME,$0-12
+ JMP runtime·memhash64Fallback(SB)
+
+TEXT runtime·return0(SB),NOSPLIT,$0
+ MOVW $0, R0
+ RET
+
+TEXT runtime·procyield(SB),NOSPLIT|NOFRAME,$0
+ MOVW cycles+0(FP), R1
+ MOVW $0, R0
+yieldloop:
+ WORD $0xe320f001 // YIELD (NOP pre-ARMv6K)
+ CMP R0, R1
+ B.NE 2(PC)
+ RET
+ SUB $1, R1
+ B yieldloop
+
+// Called from cgo wrappers, this function returns g->m->curg.stack.hi.
+// Must obey the gcc calling convention.
+TEXT _cgo_topofstack(SB),NOSPLIT,$8
+ // R11 and g register are clobbered by load_g. They are
+ // callee-save in the gcc calling convention, so save them here.
+ MOVW R11, saveR11-4(SP)
+ MOVW g, saveG-8(SP)
+
+ BL runtime·load_g(SB)
+ MOVW g_m(g), R0
+ MOVW m_curg(R0), R0
+ MOVW (g_stack+stack_hi)(R0), R0
+
+ MOVW saveG-8(SP), g
+ MOVW saveR11-4(SP), R11
+ RET
+
+// The top-most function running on a goroutine
+// returns to goexit+PCQuantum.
+TEXT runtime·goexit(SB),NOSPLIT|NOFRAME|TOPFRAME,$0-0
+ MOVW R0, R0 // NOP
+ BL runtime·goexit1(SB) // does not return
+ // traceback from goexit1 must hit code range of goexit
+ MOVW R0, R0 // NOP
+
+// x -> x/1000000, x%1000000, called from Go with args, results on stack.
+TEXT runtime·usplit(SB),NOSPLIT,$0-12
+ MOVW x+0(FP), R0
+ CALL runtime·usplitR0(SB)
+ MOVW R0, q+4(FP)
+ MOVW R1, r+8(FP)
+ RET
+
+// R0, R1 = R0/1000000, R0%1000000
+TEXT runtime·usplitR0(SB),NOSPLIT,$0
+ // magic multiply to avoid software divide without available m.
+ // see output of go tool compile -S for x/1000000.
+ MOVW R0, R3
+ MOVW $1125899907, R1
+ MULLU R1, R0, (R0, R1)
+ MOVW R0>>18, R0
+ MOVW $1000000, R1
+ MULU R0, R1
+ SUB R1, R3, R1
+ RET
+
+// This is called from .init_array and follows the platform, not Go, ABI.
+TEXT runtime·addmoduledata(SB),NOSPLIT,$0-0
+ MOVW R9, saver9-4(SP) // The access to global variables below implicitly uses R9, which is callee-save
+ MOVW R11, saver11-8(SP) // Likewise, R11 is the temp register, but callee-save in C ABI
+ MOVW runtime·lastmoduledatap(SB), R1
+ MOVW R0, moduledata_next(R1)
+ MOVW R0, runtime·lastmoduledatap(SB)
+ MOVW saver11-8(SP), R11
+ MOVW saver9-4(SP), R9
+ RET
+
+TEXT ·checkASM(SB),NOSPLIT,$0-1
+ MOVW $1, R3
+ MOVB R3, ret+0(FP)
+ RET
+
+// gcWriteBarrier performs a heap pointer write and informs the GC.
+//
+// gcWriteBarrier does NOT follow the Go ABI. It takes two arguments:
+// - R2 is the destination of the write
+// - R3 is the value being written at R2
+// It clobbers condition codes.
+// It does not clobber any other general-purpose registers,
+// but may clobber others (e.g., floating point registers).
+// The act of CALLing gcWriteBarrier will clobber R14 (LR).
+TEXT runtime·gcWriteBarrier(SB),NOSPLIT|NOFRAME,$0
+ // Save the registers clobbered by the fast path.
+ MOVM.DB.W [R0,R1], (R13)
+ MOVW g_m(g), R0
+ MOVW m_p(R0), R0
+ MOVW (p_wbBuf+wbBuf_next)(R0), R1
+ // Increment wbBuf.next position.
+ ADD $8, R1
+ MOVW R1, (p_wbBuf+wbBuf_next)(R0)
+ MOVW (p_wbBuf+wbBuf_end)(R0), R0
+ CMP R1, R0
+ // Record the write.
+ MOVW R3, -8(R1) // Record value
+ MOVW (R2), R0 // TODO: This turns bad writes into bad reads.
+ MOVW R0, -4(R1) // Record *slot
+ // Is the buffer full? (flags set in CMP above)
+ B.EQ flush
+ret:
+ MOVM.IA.W (R13), [R0,R1]
+ // Do the write.
+ MOVW R3, (R2)
+ RET
+
+flush:
+ // Save all general purpose registers since these could be
+ // clobbered by wbBufFlush and were not saved by the caller.
+ //
+ // R0 and R1 were saved at entry.
+ // R10 is g, so preserved.
+ // R11 is linker temp, so no need to save.
+ // R13 is stack pointer.
+ // R15 is PC.
+ //
+ // This also sets up R2 and R3 as the arguments to wbBufFlush.
+ MOVM.DB.W [R2-R9,R12], (R13)
+ // Save R14 (LR) because the fast path above doesn't save it,
+ // but needs it to RET. This is after the MOVM so it appears below
+ // the arguments in the stack frame.
+ MOVM.DB.W [R14], (R13)
+
+ // This takes arguments R2 and R3.
+ CALL runtime·wbBufFlush(SB)
+
+ MOVM.IA.W (R13), [R14]
+ MOVM.IA.W (R13), [R2-R9,R12]
+ JMP ret
+
+// Note: these functions use a special calling convention to save generated code space.
+// Arguments are passed in registers, but the space for those arguments are allocated
+// in the caller's stack frame. These stubs write the args into that stack space and
+// then tail call to the corresponding runtime handler.
+// The tail call makes these stubs disappear in backtraces.
+TEXT runtime·panicIndex(SB),NOSPLIT,$0-8
+ MOVW R0, x+0(FP)
+ MOVW R1, y+4(FP)
+ JMP runtime·goPanicIndex(SB)
+TEXT runtime·panicIndexU(SB),NOSPLIT,$0-8
+ MOVW R0, x+0(FP)
+ MOVW R1, y+4(FP)
+ JMP runtime·goPanicIndexU(SB)
+TEXT runtime·panicSliceAlen(SB),NOSPLIT,$0-8
+ MOVW R1, x+0(FP)
+ MOVW R2, y+4(FP)
+ JMP runtime·goPanicSliceAlen(SB)
+TEXT runtime·panicSliceAlenU(SB),NOSPLIT,$0-8
+ MOVW R1, x+0(FP)
+ MOVW R2, y+4(FP)
+ JMP runtime·goPanicSliceAlenU(SB)
+TEXT runtime·panicSliceAcap(SB),NOSPLIT,$0-8
+ MOVW R1, x+0(FP)
+ MOVW R2, y+4(FP)
+ JMP runtime·goPanicSliceAcap(SB)
+TEXT runtime·panicSliceAcapU(SB),NOSPLIT,$0-8
+ MOVW R1, x+0(FP)
+ MOVW R2, y+4(FP)
+ JMP runtime·goPanicSliceAcapU(SB)
+TEXT runtime·panicSliceB(SB),NOSPLIT,$0-8
+ MOVW R0, x+0(FP)
+ MOVW R1, y+4(FP)
+ JMP runtime·goPanicSliceB(SB)
+TEXT runtime·panicSliceBU(SB),NOSPLIT,$0-8
+ MOVW R0, x+0(FP)
+ MOVW R1, y+4(FP)
+ JMP runtime·goPanicSliceBU(SB)
+TEXT runtime·panicSlice3Alen(SB),NOSPLIT,$0-8
+ MOVW R2, x+0(FP)
+ MOVW R3, y+4(FP)
+ JMP runtime·goPanicSlice3Alen(SB)
+TEXT runtime·panicSlice3AlenU(SB),NOSPLIT,$0-8
+ MOVW R2, x+0(FP)
+ MOVW R3, y+4(FP)
+ JMP runtime·goPanicSlice3AlenU(SB)
+TEXT runtime·panicSlice3Acap(SB),NOSPLIT,$0-8
+ MOVW R2, x+0(FP)
+ MOVW R3, y+4(FP)
+ JMP runtime·goPanicSlice3Acap(SB)
+TEXT runtime·panicSlice3AcapU(SB),NOSPLIT,$0-8
+ MOVW R2, x+0(FP)
+ MOVW R3, y+4(FP)
+ JMP runtime·goPanicSlice3AcapU(SB)
+TEXT runtime·panicSlice3B(SB),NOSPLIT,$0-8
+ MOVW R1, x+0(FP)
+ MOVW R2, y+4(FP)
+ JMP runtime·goPanicSlice3B(SB)
+TEXT runtime·panicSlice3BU(SB),NOSPLIT,$0-8
+ MOVW R1, x+0(FP)
+ MOVW R2, y+4(FP)
+ JMP runtime·goPanicSlice3BU(SB)
+TEXT runtime·panicSlice3C(SB),NOSPLIT,$0-8
+ MOVW R0, x+0(FP)
+ MOVW R1, y+4(FP)
+ JMP runtime·goPanicSlice3C(SB)
+TEXT runtime·panicSlice3CU(SB),NOSPLIT,$0-8
+ MOVW R0, x+0(FP)
+ MOVW R1, y+4(FP)
+ JMP runtime·goPanicSlice3CU(SB)
+TEXT runtime·panicSliceConvert(SB),NOSPLIT,$0-8
+ MOVW R2, x+0(FP)
+ MOVW R3, y+4(FP)
+ JMP runtime·goPanicSliceConvert(SB)
+
+// Extended versions for 64-bit indexes.
+TEXT runtime·panicExtendIndex(SB),NOSPLIT,$0-12
+ MOVW R4, hi+0(FP)
+ MOVW R0, lo+4(FP)
+ MOVW R1, y+8(FP)
+ JMP runtime·goPanicExtendIndex(SB)
+TEXT runtime·panicExtendIndexU(SB),NOSPLIT,$0-12
+ MOVW R4, hi+0(FP)
+ MOVW R0, lo+4(FP)
+ MOVW R1, y+8(FP)
+ JMP runtime·goPanicExtendIndexU(SB)
+TEXT runtime·panicExtendSliceAlen(SB),NOSPLIT,$0-12
+ MOVW R4, hi+0(FP)
+ MOVW R1, lo+4(FP)
+ MOVW R2, y+8(FP)
+ JMP runtime·goPanicExtendSliceAlen(SB)
+TEXT runtime·panicExtendSliceAlenU(SB),NOSPLIT,$0-12
+ MOVW R4, hi+0(FP)
+ MOVW R1, lo+4(FP)
+ MOVW R2, y+8(FP)
+ JMP runtime·goPanicExtendSliceAlenU(SB)
+TEXT runtime·panicExtendSliceAcap(SB),NOSPLIT,$0-12
+ MOVW R4, hi+0(FP)
+ MOVW R1, lo+4(FP)
+ MOVW R2, y+8(FP)
+ JMP runtime·goPanicExtendSliceAcap(SB)
+TEXT runtime·panicExtendSliceAcapU(SB),NOSPLIT,$0-12
+ MOVW R4, hi+0(FP)
+ MOVW R1, lo+4(FP)
+ MOVW R2, y+8(FP)
+ JMP runtime·goPanicExtendSliceAcapU(SB)
+TEXT runtime·panicExtendSliceB(SB),NOSPLIT,$0-12
+ MOVW R4, hi+0(FP)
+ MOVW R0, lo+4(FP)
+ MOVW R1, y+8(FP)
+ JMP runtime·goPanicExtendSliceB(SB)
+TEXT runtime·panicExtendSliceBU(SB),NOSPLIT,$0-12
+ MOVW R4, hi+0(FP)
+ MOVW R0, lo+4(FP)
+ MOVW R1, y+8(FP)
+ JMP runtime·goPanicExtendSliceBU(SB)
+TEXT runtime·panicExtendSlice3Alen(SB),NOSPLIT,$0-12
+ MOVW R4, hi+0(FP)
+ MOVW R2, lo+4(FP)
+ MOVW R3, y+8(FP)
+ JMP runtime·goPanicExtendSlice3Alen(SB)
+TEXT runtime·panicExtendSlice3AlenU(SB),NOSPLIT,$0-12
+ MOVW R4, hi+0(FP)
+ MOVW R2, lo+4(FP)
+ MOVW R3, y+8(FP)
+ JMP runtime·goPanicExtendSlice3AlenU(SB)
+TEXT runtime·panicExtendSlice3Acap(SB),NOSPLIT,$0-12
+ MOVW R4, hi+0(FP)
+ MOVW R2, lo+4(FP)
+ MOVW R3, y+8(FP)
+ JMP runtime·goPanicExtendSlice3Acap(SB)
+TEXT runtime·panicExtendSlice3AcapU(SB),NOSPLIT,$0-12
+ MOVW R4, hi+0(FP)
+ MOVW R2, lo+4(FP)
+ MOVW R3, y+8(FP)
+ JMP runtime·goPanicExtendSlice3AcapU(SB)
+TEXT runtime·panicExtendSlice3B(SB),NOSPLIT,$0-12
+ MOVW R4, hi+0(FP)
+ MOVW R1, lo+4(FP)
+ MOVW R2, y+8(FP)
+ JMP runtime·goPanicExtendSlice3B(SB)
+TEXT runtime·panicExtendSlice3BU(SB),NOSPLIT,$0-12
+ MOVW R4, hi+0(FP)
+ MOVW R1, lo+4(FP)
+ MOVW R2, y+8(FP)
+ JMP runtime·goPanicExtendSlice3BU(SB)
+TEXT runtime·panicExtendSlice3C(SB),NOSPLIT,$0-12
+ MOVW R4, hi+0(FP)
+ MOVW R0, lo+4(FP)
+ MOVW R1, y+8(FP)
+ JMP runtime·goPanicExtendSlice3C(SB)
+TEXT runtime·panicExtendSlice3CU(SB),NOSPLIT,$0-12
+ MOVW R4, hi+0(FP)
+ MOVW R0, lo+4(FP)
+ MOVW R1, y+8(FP)
+ JMP runtime·goPanicExtendSlice3CU(SB)
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-19 11:17:01 +0000