1 files changed, 655 insertions, 0 deletions
diff --git a/src/runtime/sys_linux_arm.s b/src/runtime/sys_linux_arm.s
new file mode 100644
index 0000000..7b8c4f0
--- /dev/null
+++ b/src/runtime/sys_linux_arm.s
@@ -0,0 +1,655 @@
+// 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.
+
+//
+// System calls and other sys.stuff for arm, Linux
+//
+
+#include "go_asm.h"
+#include "go_tls.h"
+#include "textflag.h"
+
+#define CLOCK_REALTIME	0
+#define CLOCK_MONOTONIC	1
+
+// for EABI, as we don't support OABI
+#define SYS_BASE 0x0
+
+#define SYS_exit (SYS_BASE + 1)
+#define SYS_read (SYS_BASE + 3)
+#define SYS_write (SYS_BASE + 4)
+#define SYS_open (SYS_BASE + 5)
+#define SYS_close (SYS_BASE + 6)
+#define SYS_getpid (SYS_BASE + 20)
+#define SYS_kill (SYS_BASE + 37)
+#define SYS_clone (SYS_BASE + 120)
+#define SYS_rt_sigreturn (SYS_BASE + 173)
+#define SYS_rt_sigaction (SYS_BASE + 174)
+#define SYS_rt_sigprocmask (SYS_BASE + 175)
+#define SYS_sigaltstack (SYS_BASE + 186)
+#define SYS_mmap2 (SYS_BASE + 192)
+#define SYS_futex (SYS_BASE + 240)
+#define SYS_exit_group (SYS_BASE + 248)
+#define SYS_munmap (SYS_BASE + 91)
+#define SYS_madvise (SYS_BASE + 220)
+#define SYS_setitimer (SYS_BASE + 104)
+#define SYS_mincore (SYS_BASE + 219)
+#define SYS_gettid (SYS_BASE + 224)
+#define SYS_tgkill (SYS_BASE + 268)
+#define SYS_sched_yield (SYS_BASE + 158)
+#define SYS_nanosleep (SYS_BASE + 162)
+#define SYS_sched_getaffinity (SYS_BASE + 242)
+#define SYS_clock_gettime (SYS_BASE + 263)
+#define SYS_timer_create (SYS_BASE + 257)
+#define SYS_timer_settime (SYS_BASE + 258)
+#define SYS_timer_delete (SYS_BASE + 261)
+#define SYS_pipe2 (SYS_BASE + 359)
+#define SYS_access (SYS_BASE + 33)
+#define SYS_connect (SYS_BASE + 283)
+#define SYS_socket (SYS_BASE + 281)
+#define SYS_brk (SYS_BASE + 45)
+
+#define ARM_BASE (SYS_BASE + 0x0f0000)
+
+TEXT runtime·open(SB),NOSPLIT,$0
+	MOVW	name+0(FP), R0
+	MOVW	mode+4(FP), R1
+	MOVW	perm+8(FP), R2
+	MOVW	$SYS_open, R7
+	SWI	$0
+	MOVW	$0xfffff001, R1
+	CMP	R1, R0
+	MOVW.HI	$-1, R0
+	MOVW	R0, ret+12(FP)
+	RET
+
+TEXT runtime·closefd(SB),NOSPLIT,$0
+	MOVW	fd+0(FP), R0
+	MOVW	$SYS_close, R7
+	SWI	$0
+	MOVW	$0xfffff001, R1
+	CMP	R1, R0
+	MOVW.HI	$-1, R0
+	MOVW	R0, ret+4(FP)
+	RET
+
+TEXT runtime·write1(SB),NOSPLIT,$0
+	MOVW	fd+0(FP), R0
+	MOVW	p+4(FP), R1
+	MOVW	n+8(FP), R2
+	MOVW	$SYS_write, R7
+	SWI	$0
+	MOVW	R0, ret+12(FP)
+	RET
+
+TEXT runtime·read(SB),NOSPLIT,$0
+	MOVW	fd+0(FP), R0
+	MOVW	p+4(FP), R1
+	MOVW	n+8(FP), R2
+	MOVW	$SYS_read, R7
+	SWI	$0
+	MOVW	R0, ret+12(FP)
+	RET
+
+// func pipe2(flags int32) (r, w int32, errno int32)
+TEXT runtime·pipe2(SB),NOSPLIT,$0-16
+	MOVW	$r+4(FP), R0
+	MOVW	flags+0(FP), R1
+	MOVW	$SYS_pipe2, R7
+	SWI	$0
+	MOVW	R0, errno+12(FP)
+	RET
+
+TEXT runtime·exit(SB),NOSPLIT|NOFRAME,$0
+	MOVW	code+0(FP), R0
+	MOVW	$SYS_exit_group, R7
+	SWI	$0
+	MOVW	$1234, R0
+	MOVW	$1002, R1
+	MOVW	R0, (R1)	// fail hard
+
+TEXT exit1<>(SB),NOSPLIT|NOFRAME,$0
+	MOVW	code+0(FP), R0
+	MOVW	$SYS_exit, R7
+	SWI	$0
+	MOVW	$1234, R0
+	MOVW	$1003, R1
+	MOVW	R0, (R1)	// fail hard
+
+// func exitThread(wait *atomic.Uint32)
+TEXT runtime·exitThread(SB),NOSPLIT|NOFRAME,$0-4
+	MOVW	wait+0(FP), R0
+	// We're done using the stack.
+	// Alas, there's no reliable way to make this write atomic
+	// without potentially using the stack. So it goes.
+	MOVW	$0, R1
+	MOVW	R1, (R0)
+	MOVW	$0, R0	// exit code
+	MOVW	$SYS_exit, R7
+	SWI	$0
+	MOVW	$1234, R0
+	MOVW	$1004, R1
+	MOVW	R0, (R1)	// fail hard
+	JMP	0(PC)
+
+TEXT runtime·gettid(SB),NOSPLIT,$0-4
+	MOVW	$SYS_gettid, R7
+	SWI	$0
+	MOVW	R0, ret+0(FP)
+	RET
+
+TEXT	runtime·raise(SB),NOSPLIT|NOFRAME,$0
+	MOVW	$SYS_getpid, R7
+	SWI	$0
+	MOVW	R0, R4
+	MOVW	$SYS_gettid, R7
+	SWI	$0
+	MOVW	R0, R1	// arg 2 tid
+	MOVW	R4, R0	// arg 1 pid
+	MOVW	sig+0(FP), R2	// arg 3
+	MOVW	$SYS_tgkill, R7
+	SWI	$0
+	RET
+
+TEXT	runtime·raiseproc(SB),NOSPLIT|NOFRAME,$0
+	MOVW	$SYS_getpid, R7
+	SWI	$0
+	// arg 1 tid already in R0 from getpid
+	MOVW	sig+0(FP), R1	// arg 2 - signal
+	MOVW	$SYS_kill, R7
+	SWI	$0
+	RET
+
+TEXT ·getpid(SB),NOSPLIT,$0-4
+	MOVW	$SYS_getpid, R7
+	SWI	$0
+	MOVW	R0, ret+0(FP)
+	RET
+
+TEXT ·tgkill(SB),NOSPLIT,$0-12
+	MOVW	tgid+0(FP), R0
+	MOVW	tid+4(FP), R1
+	MOVW	sig+8(FP), R2
+	MOVW	$SYS_tgkill, R7
+	SWI	$0
+	RET
+
+TEXT runtime·mmap(SB),NOSPLIT,$0
+	MOVW	addr+0(FP), R0
+	MOVW	n+4(FP), R1
+	MOVW	prot+8(FP), R2
+	MOVW	flags+12(FP), R3
+	MOVW	fd+16(FP), R4
+	MOVW	off+20(FP), R5
+	MOVW	$SYS_mmap2, R7
+	SWI	$0
+	MOVW	$0xfffff001, R6
+	CMP		R6, R0
+	MOVW	$0, R1
+	RSB.HI	$0, R0
+	MOVW.HI	R0, R1		// if error, put in R1
+	MOVW.HI	$0, R0
+	MOVW	R0, p+24(FP)
+	MOVW	R1, err+28(FP)
+	RET
+
+TEXT runtime·munmap(SB),NOSPLIT,$0
+	MOVW	addr+0(FP), R0
+	MOVW	n+4(FP), R1
+	MOVW	$SYS_munmap, R7
+	SWI	$0
+	MOVW	$0xfffff001, R6
+	CMP 	R6, R0
+	MOVW.HI	$0, R8  // crash on syscall failure
+	MOVW.HI	R8, (R8)
+	RET
+
+TEXT runtime·madvise(SB),NOSPLIT,$0
+	MOVW	addr+0(FP), R0
+	MOVW	n+4(FP), R1
+	MOVW	flags+8(FP), R2
+	MOVW	$SYS_madvise, R7
+	SWI	$0
+	MOVW	R0, ret+12(FP)
+	RET
+
+TEXT runtime·setitimer(SB),NOSPLIT,$0
+	MOVW	mode+0(FP), R0
+	MOVW	new+4(FP), R1
+	MOVW	old+8(FP), R2
+	MOVW	$SYS_setitimer, R7
+	SWI	$0
+	RET
+
+TEXT runtime·timer_create(SB),NOSPLIT,$0-16
+	MOVW	clockid+0(FP), R0
+	MOVW	sevp+4(FP), R1
+	MOVW	timerid+8(FP), R2
+	MOVW	$SYS_timer_create, R7
+	SWI	$0
+	MOVW	R0, ret+12(FP)
+	RET
+
+TEXT runtime·timer_settime(SB),NOSPLIT,$0-20
+	MOVW	timerid+0(FP), R0
+	MOVW	flags+4(FP), R1
+	MOVW	new+8(FP), R2
+	MOVW	old+12(FP), R3
+	MOVW	$SYS_timer_settime, R7
+	SWI	$0
+	MOVW	R0, ret+16(FP)
+	RET
+
+TEXT runtime·timer_delete(SB),NOSPLIT,$0-8
+	MOVW	timerid+0(FP), R0
+	MOVW	$SYS_timer_delete, R7
+	SWI	$0
+	MOVW	R0, ret+4(FP)
+	RET
+
+TEXT runtime·mincore(SB),NOSPLIT,$0
+	MOVW	addr+0(FP), R0
+	MOVW	n+4(FP), R1
+	MOVW	dst+8(FP), R2
+	MOVW	$SYS_mincore, R7
+	SWI	$0
+	MOVW	R0, ret+12(FP)
+	RET
+
+// Call a VDSO function.
+//
+// R0-R3: arguments to VDSO function (C calling convention)
+// R4: uintptr function to call
+//
+// There is no return value.
+TEXT runtime·vdsoCall(SB),NOSPLIT,$8-0
+	// R0-R3 may be arguments to fn, do not touch.
+	// R4 is function to call.
+	// R5-R9 are available as locals. They are unchanged by the C call
+	// (callee-save).
+
+	// We don't know how much stack space the VDSO code will need,
+	// so switch to g0.
+
+	// Save old SP. Use R13 instead of SP to avoid linker rewriting the offsets.
+	MOVW	R13, R5
+
+	MOVW	g_m(g), R6
+
+	// Set vdsoPC and vdsoSP for SIGPROF traceback.
+	// Save the old values on stack and restore them on exit,
+	// so this function is reentrant.
+	MOVW	m_vdsoPC(R6), R7
+	MOVW	m_vdsoSP(R6), R8
+	MOVW	R7, 4(R13)
+	MOVW	R8, 8(R13)
+
+	MOVW	$sp-4(FP), R7 // caller's SP
+	MOVW	LR, m_vdsoPC(R6)
+	MOVW	R7, m_vdsoSP(R6)
+
+	MOVW	m_curg(R6), R7
+
+	CMP	g, R7		// Only switch if on curg.
+	B.NE	noswitch
+
+	MOVW	m_g0(R6), R7
+	MOVW	(g_sched+gobuf_sp)(R7), R13	 // Set SP to g0 stack
+
+noswitch:
+	BIC	$0x7, R13	// Align for C code
+
+	// Store g on gsignal's stack, so if we receive a signal
+	// during VDSO code we can find the g.
+
+	// When using cgo, we already saved g on TLS, also don't save g here.
+	MOVB	runtime·iscgo(SB), R7
+	CMP	$0, R7
+	BNE	nosaveg
+	// If we don't have a signal stack, we won't receive signal, so don't
+	// bother saving g.
+	MOVW	m_gsignal(R6), R7          // g.m.gsignal
+	CMP	$0, R7
+	BEQ	nosaveg
+	// Don't save g if we are already on the signal stack, as we won't get
+	// a nested signal.
+	CMP	g, R7
+	BEQ	nosaveg
+	// If we don't have a signal stack, we won't receive signal, so don't
+	// bother saving g.
+	MOVW	(g_stack+stack_lo)(R7), R7 // g.m.gsignal.stack.lo
+	CMP	$0, R7
+	BEQ	nosaveg
+	MOVW	g, (R7)
+
+	BL	(R4)
+
+	MOVW	$0, R8
+	MOVW	R8, (R7) // clear g slot
+
+	JMP	finish
+
+nosaveg:
+	BL	(R4)
+
+finish:
+	MOVW	R5, R13		// Restore real SP
+	// Restore vdsoPC, vdsoSP
+	// We don't worry about being signaled between the two stores.
+	// If we are not in a signal handler, we'll restore vdsoSP to 0,
+	// and no one will care about vdsoPC. If we are in a signal handler,
+	// we cannot receive another signal.
+	MOVW	8(R13), R7
+	MOVW	R7, m_vdsoSP(R6)
+	MOVW	4(R13), R7
+	MOVW	R7, m_vdsoPC(R6)
+	RET
+
+TEXT runtime·walltime(SB),NOSPLIT,$12-12
+	MOVW	$CLOCK_REALTIME, R0
+	MOVW	$spec-12(SP), R1	// timespec
+
+	MOVW	runtime·vdsoClockgettimeSym(SB), R4
+	CMP	$0, R4
+	B.EQ	fallback
+
+	BL	runtime·vdsoCall(SB)
+
+	JMP	finish
+
+fallback:
+	MOVW	$SYS_clock_gettime, R7
+	SWI	$0
+
+finish:
+	MOVW	sec-12(SP), R0  // sec
+	MOVW	nsec-8(SP), R2  // nsec
+
+	MOVW	R0, sec_lo+0(FP)
+	MOVW	$0, R1
+	MOVW	R1, sec_hi+4(FP)
+	MOVW	R2, nsec+8(FP)
+	RET
+
+// func nanotime1() int64
+TEXT runtime·nanotime1(SB),NOSPLIT,$12-8
+	MOVW	$CLOCK_MONOTONIC, R0
+	MOVW	$spec-12(SP), R1	// timespec
+
+	MOVW	runtime·vdsoClockgettimeSym(SB), R4
+	CMP	$0, R4
+	B.EQ	fallback
+
+	BL	runtime·vdsoCall(SB)
+
+	JMP	finish
+
+fallback:
+	MOVW	$SYS_clock_gettime, R7
+	SWI	$0
+
+finish:
+	MOVW	sec-12(SP), R0  // sec
+	MOVW	nsec-8(SP), R2  // nsec
+
+	MOVW	$1000000000, R3
+	MULLU	R0, R3, (R1, R0)
+	ADD.S	R2, R0
+	ADC	$0, R1	// Add carry bit to upper half.
+
+	MOVW	R0, ret_lo+0(FP)
+	MOVW	R1, ret_hi+4(FP)
+
+	RET
+
+// int32 futex(int32 *uaddr, int32 op, int32 val,
+//	struct timespec *timeout, int32 *uaddr2, int32 val2);
+TEXT runtime·futex(SB),NOSPLIT,$0
+	MOVW    addr+0(FP), R0
+	MOVW    op+4(FP), R1
+	MOVW    val+8(FP), R2
+	MOVW    ts+12(FP), R3
+	MOVW    addr2+16(FP), R4
+	MOVW    val3+20(FP), R5
+	MOVW	$SYS_futex, R7
+	SWI	$0
+	MOVW	R0, ret+24(FP)
+	RET
+
+// int32 clone(int32 flags, void *stack, M *mp, G *gp, void (*fn)(void));
+TEXT runtime·clone(SB),NOSPLIT,$0
+	MOVW	flags+0(FP), R0
+	MOVW	stk+4(FP), R1
+	MOVW	$0, R2	// parent tid ptr
+	MOVW	$0, R3	// tls_val
+	MOVW	$0, R4	// child tid ptr
+	MOVW	$0, R5
+
+	// Copy mp, gp, fn off parent stack for use by child.
+	MOVW	$-16(R1), R1
+	MOVW	mp+8(FP), R6
+	MOVW	R6, 0(R1)
+	MOVW	gp+12(FP), R6
+	MOVW	R6, 4(R1)
+	MOVW	fn+16(FP), R6
+	MOVW	R6, 8(R1)
+	MOVW	$1234, R6
+	MOVW	R6, 12(R1)
+
+	MOVW	$SYS_clone, R7
+	SWI	$0
+
+	// In parent, return.
+	CMP	$0, R0
+	BEQ	3(PC)
+	MOVW	R0, ret+20(FP)
+	RET
+
+	// Paranoia: check that SP is as we expect. Use R13 to avoid linker 'fixup'
+	NOP	R13	// tell vet SP/R13 changed - stop checking offsets
+	MOVW	12(R13), R0
+	MOVW	$1234, R1
+	CMP	R0, R1
+	BEQ	2(PC)
+	BL	runtime·abort(SB)
+
+	MOVW	0(R13), R8    // m
+	MOVW	4(R13), R0    // g
+
+	CMP	$0, R8
+	BEQ	nog
+	CMP	$0, R0
+	BEQ	nog
+
+	MOVW	R0, g
+	MOVW	R8, g_m(g)
+
+	// paranoia; check they are not nil
+	MOVW	0(R8), R0
+	MOVW	0(g), R0
+
+	BL	runtime·emptyfunc(SB)	// fault if stack check is wrong
+
+	// Initialize m->procid to Linux tid
+	MOVW	$SYS_gettid, R7
+	SWI	$0
+	MOVW	g_m(g), R8
+	MOVW	R0, m_procid(R8)
+
+nog:
+	// Call fn
+	MOVW	8(R13), R0
+	MOVW	$16(R13), R13
+	BL	(R0)
+
+	// It shouldn't return. If it does, exit that thread.
+	SUB	$16, R13 // restore the stack pointer to avoid memory corruption
+	MOVW	$0, R0
+	MOVW	R0, 4(R13)
+	BL	exit1<>(SB)
+
+	MOVW	$1234, R0
+	MOVW	$1005, R1
+	MOVW	R0, (R1)
+
+TEXT runtime·sigaltstack(SB),NOSPLIT,$0
+	MOVW	new+0(FP), R0
+	MOVW	old+4(FP), R1
+	MOVW	$SYS_sigaltstack, R7
+	SWI	$0
+	MOVW	$0xfffff001, R6
+	CMP 	R6, R0
+	MOVW.HI	$0, R8  // crash on syscall failure
+	MOVW.HI	R8, (R8)
+	RET
+
+TEXT runtime·sigfwd(SB),NOSPLIT,$0-16
+	MOVW	sig+4(FP), R0
+	MOVW	info+8(FP), R1
+	MOVW	ctx+12(FP), R2
+	MOVW	fn+0(FP), R11
+	MOVW	R13, R4
+	SUB	$24, R13
+	BIC	$0x7, R13 // alignment for ELF ABI
+	BL	(R11)
+	MOVW	R4, R13
+	RET
+
+TEXT runtime·sigtramp(SB),NOSPLIT|TOPFRAME,$0
+	// Reserve space for callee-save registers and arguments.
+	MOVM.DB.W [R4-R11], (R13)
+	SUB	$16, R13
+
+	// this might be called in external code context,
+	// where g is not set.
+	// first save R0, because runtime·load_g will clobber it
+	MOVW	R0, 4(R13)
+	MOVB	runtime·iscgo(SB), R0
+	CMP 	$0, R0
+	BL.NE	runtime·load_g(SB)
+
+	MOVW	R1, 8(R13)
+	MOVW	R2, 12(R13)
+	MOVW  	$runtime·sigtrampgo(SB), R11
+	BL	(R11)
+
+	// Restore callee-save registers.
+	ADD	$16, R13
+	MOVM.IA.W (R13), [R4-R11]
+
+	RET
+
+TEXT runtime·cgoSigtramp(SB),NOSPLIT,$0
+	MOVW  	$runtime·sigtramp(SB), R11
+	B	(R11)
+
+TEXT runtime·rtsigprocmask(SB),NOSPLIT,$0
+	MOVW	how+0(FP), R0
+	MOVW	new+4(FP), R1
+	MOVW	old+8(FP), R2
+	MOVW	size+12(FP), R3
+	MOVW	$SYS_rt_sigprocmask, R7
+	SWI	$0
+	RET
+
+TEXT runtime·rt_sigaction(SB),NOSPLIT,$0
+	MOVW	sig+0(FP), R0
+	MOVW	new+4(FP), R1
+	MOVW	old+8(FP), R2
+	MOVW	size+12(FP), R3
+	MOVW	$SYS_rt_sigaction, R7
+	SWI	$0
+	MOVW	R0, ret+16(FP)
+	RET
+
+TEXT runtime·usleep(SB),NOSPLIT,$12
+	MOVW	usec+0(FP), R0
+	CALL	runtime·usplitR0(SB)
+	MOVW	R0, 4(R13)
+	MOVW	$1000, R0	// usec to nsec
+	MUL	R0, R1
+	MOVW	R1, 8(R13)
+	MOVW	$4(R13), R0
+	MOVW	$0, R1
+	MOVW	$SYS_nanosleep, R7
+	SWI	$0
+	RET
+
+// As for cas, memory barriers are complicated on ARM, but the kernel
+// provides a user helper. ARMv5 does not support SMP and has no
+// memory barrier instruction at all. ARMv6 added SMP support and has
+// a memory barrier, but it requires writing to a coprocessor
+// register. ARMv7 introduced the DMB instruction, but it's expensive
+// even on single-core devices. The kernel helper takes care of all of
+// this for us.
+
+TEXT kernelPublicationBarrier<>(SB),NOSPLIT,$0
+	// void __kuser_memory_barrier(void);
+	MOVW	$0xffff0fa0, R11
+	CALL	(R11)
+	RET
+
+TEXT ·publicationBarrier(SB),NOSPLIT,$0
+	MOVB	·goarm(SB), R11
+	CMP	$7, R11
+	BLT	2(PC)
+	JMP	·armPublicationBarrier(SB)
+	JMP	kernelPublicationBarrier<>(SB) // extra layer so this function is leaf and no SP adjustment on GOARM=7
+
+TEXT runtime·osyield(SB),NOSPLIT,$0
+	MOVW	$SYS_sched_yield, R7
+	SWI	$0
+	RET
+
+TEXT runtime·sched_getaffinity(SB),NOSPLIT,$0
+	MOVW	pid+0(FP), R0
+	MOVW	len+4(FP), R1
+	MOVW	buf+8(FP), R2
+	MOVW	$SYS_sched_getaffinity, R7
+	SWI	$0
+	MOVW	R0, ret+12(FP)
+	RET
+
+// b __kuser_get_tls @ 0xffff0fe0
+TEXT runtime·read_tls_fallback(SB),NOSPLIT|NOFRAME,$0
+	MOVW	$0xffff0fe0, R0
+	B	(R0)
+
+TEXT runtime·access(SB),NOSPLIT,$0
+	MOVW	name+0(FP), R0
+	MOVW	mode+4(FP), R1
+	MOVW	$SYS_access, R7
+	SWI	$0
+	MOVW	R0, ret+8(FP)
+	RET
+
+TEXT runtime·connect(SB),NOSPLIT,$0
+	MOVW	fd+0(FP), R0
+	MOVW	addr+4(FP), R1
+	MOVW	len+8(FP), R2
+	MOVW	$SYS_connect, R7
+	SWI	$0
+	MOVW	R0, ret+12(FP)
+	RET
+
+TEXT runtime·socket(SB),NOSPLIT,$0
+	MOVW	domain+0(FP), R0
+	MOVW	typ+4(FP), R1
+	MOVW	prot+8(FP), R2
+	MOVW	$SYS_socket, R7
+	SWI	$0
+	MOVW	R0, ret+12(FP)
+	RET
+
+// func sbrk0() uintptr
+TEXT runtime·sbrk0(SB),NOSPLIT,$0-4
+	// Implemented as brk(NULL).
+	MOVW	$0, R0
+	MOVW	$SYS_brk, R7
+	SWI	$0
+	MOVW	R0, ret+0(FP)
+	RET
+
+TEXT runtime·sigreturn(SB),NOSPLIT,$0-0
+	RET