// the user should prepare stack space in advance.
// SAVE_R19_TO_R28(offset) saves R19 ~ R28 to the stack space
// of ((offset)+0*8)(RSP) ~ ((offset)+9*8)(RSP).
//
// SAVE_F8_TO_F15(offset) saves F8 ~ F15 to the stack space
// of ((offset)+0*8)(RSP) ~ ((offset)+7*8)(RSP).
//
// R29 is not saved because Go will save and restore it.

#define SAVE_R19_TO_R28(offset) \

//
// Note that all currently shipping darwin/arm64 platforms require
// cgo and do not support c-shared.
TEXT _rt0_arm64_darwin_lib(SB),NOSPLIT,$152
	// Preserve callee-save registers.
	SAVE_R19_TO_R28(8)
	SAVE_F8_TO_F15(88)

	MOVD  R0, _rt0_arm64_darwin_lib_argc<>(SB)
	MOVD  R1, _rt0_arm64_darwin_lib_argv<>(SB)

	MOVD	$0, g // initialize g to nil

	// Synchronous initialization.
	MOVD	$runtime·libpreinit(SB), R4
	BL	(R4)

	 * Also note that at procedure entry in gc world, 8(RSP) will be the
	 *  first arg.
	 */
	SUB	$(8*24), RSP
	STP	(R0, R1), (8*1)(RSP)
	MOVD	R3, (8*3)(RSP)

	SAVE_R19_TO_R28(8*4)
	SAVE_F8_TO_F15(8*14)
	STP	(R29, R30), (8*22)(RSP)


	// Initialize Go ABI environment
	BL	runtime·load_g(SB)
	BL	runtime·cgocallback(SB)

	RESTORE_R19_TO_R28(8*4)
	RESTORE_F8_TO_F15(8*14)
	LDP	(8*22)(RSP), (R29, R30)

// When building with -buildmode=c-shared, this symbol is called when the shared
// library is loaded.
TEXT _rt0_arm64_linux_lib(SB),NOSPLIT,$184
	// Preserve callee-save registers.
	SAVE_R19_TO_R28(24)
	SAVE_F8_TO_F15(104)

	// Initialize g as null in case of using g later e.g. sigaction in cgo_sigaction.go
	MOVD	ZR, g

	MOVD	R0, _rt0_arm64_linux_lib_argc<>(SB)
	MOVD	R1, _rt0_arm64_linux_lib_argv<>(SB)

// When building with -buildmode=c-shared, this symbol is called when the shared
// library is loaded.
TEXT _rt0_arm64_freebsd_lib(SB),NOSPLIT,$184
	// Preserve callee-save registers.
	SAVE_R19_TO_R28(24)
	SAVE_F8_TO_F15(104)

	// Initialize g as null in case of using g later e.g. sigaction in cgo_sigaction.go
	MOVD	ZR, g

	MOVD	R0, _rt0_arm64_freebsd_lib_argc<>(SB)
	MOVD	R1, _rt0_arm64_freebsd_lib_argv<>(SB)

// When building with -buildmode=c-shared, this symbol is called when the shared
// library is loaded.
TEXT _rt0_arm64_netbsd_lib(SB),NOSPLIT,$184
	// Preserve callee-save registers.
	SAVE_R19_TO_R28(24)
	SAVE_F8_TO_F15(104)

	// Initialize g as null in case of using g later e.g. sigaction in cgo_sigaction.go
	MOVD	ZR, g

	MOVD	R0, _rt0_arm64_netbsd_lib_argc<>(SB)
	MOVD	R1, _rt0_arm64_netbsd_lib_argv<>(SB)

// When building with -buildmode=c-shared, this symbol is called when the shared
// library is loaded.
TEXT _rt0_arm64_openbsd_lib(SB),NOSPLIT,$184
	// Preserve callee-save registers.
	SAVE_R19_TO_R28(24)
	SAVE_F8_TO_F15(104)

	// Initialize g as null in case of using g later e.g. sigaction in cgo_sigaction.go
	MOVD	ZR, g

	MOVD	R0, _rt0_arm64_openbsd_lib_argc<>(SB)
	MOVD	R1, _rt0_arm64_openbsd_lib_argv<>(SB)

// Return value of sigtrampgo is stored in R0.
TEXT sigtramp<>(SB),NOSPLIT,$176
	// Switch from the host ABI to the Go ABI, safe args and lr.
	MOVD	R0, R5
	MOVD	R1, R6
	MOVD	LR, R7
	SAVE_R19_TO_R28(8*4)
	SAVE_F8_TO_F15(8*14)

	BL	runtime·load_g(SB)	// Clobers R0, R27, R28 (g)

	MOVD	R5, R0
	MOVD	R6, R1
	// Calling ABIInternal because TLS might be nil.
	BL	runtime·sigtrampgo<ABIInternal>(SB)

// Note: called with the C calling convention.
TEXT runtime·mstart_stub(SB),NOSPLIT,$144
	// R0 points to the m.
	// We are already on m's g0 stack.

	// Save callee-save registers.
	SAVE_R19_TO_R28(8)
	SAVE_F8_TO_F15(88)

	MOVD    m_g0(R0), g
	BL	runtime·save_g(SB)

	BL	runtime·mstart(SB)

	// Restore callee-save registers.
	RESTORE_R19_TO_R28(8)
	RESTORE_F8_TO_F15(88)

	// Go is all done with this OS thread.

	BL	(R11)
	RET

TEXT runtime·sigtramp(SB),NOSPLIT|TOPFRAME,$176
	// Save callee-save registers in the case of signal forwarding.
	// Please refer to https://golang.org/issue/31827 .
	SAVE_R19_TO_R28(8*4)
	SAVE_F8_TO_F15(8*14)

	// Save arguments.
	MOVW	R0, (8*1)(RSP)	// sig
	MOVD	R1, (8*2)(RSP)	// info
	MOVD	R2, (8*3)(RSP)	// ctx

	// this might be called in external code context,
	// where g is not set.