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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 "textflag.h"
TEXT _rt0_arm_linux(SB),NOSPLIT,$-4
MOVW (R13), R0 // argc
MOVW $4(R13), R1 // argv
MOVW $_rt0_arm_linux1(SB), R4
B (R4)
// When building with -buildmode=c-shared, this symbol is called when the shared
// library is loaded.
TEXT _rt0_arm_linux_lib(SB),NOSPLIT,$32
// 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 R11, 32(R13)
// Save argc/argv.
MOVW R0, _rt0_arm_linux_lib_argc<>(SB)
MOVW R1, _rt0_arm_linux_lib_argv<>(SB)
// Synchronous initialization.
MOVW $runtime·libpreinit(SB), R2
CALL (R2)
// Create a new thread to do the runtime initialization.
MOVW _cgo_sys_thread_create(SB), R2
CMP $0, R2
BEQ nocgo
MOVW $_rt0_arm_linux_lib_go<>(SB), R0
MOVW $0, R1
BL (R2)
B rr
nocgo:
MOVW $0x800000, R0 // stacksize = 8192KB
MOVW $_rt0_arm_linux_lib_go<>(SB), R1 // fn
MOVW R0, 4(R13)
MOVW R1, 8(R13)
BL runtime·newosproc0(SB)
rr:
// Restore callee-save registers and return.
MOVW 12(R13), R4
MOVW 16(R13), R5
MOVW 20(R13), R6
MOVW 24(R13), R7
MOVW 28(R13), R8
MOVW 32(R13), R11
RET
TEXT _rt0_arm_linux_lib_go<>(SB),NOSPLIT,$8
MOVW _rt0_arm_linux_lib_argc<>(SB), R0
MOVW _rt0_arm_linux_lib_argv<>(SB), R1
MOVW R0, 0(R13)
MOVW R1, 4(R13)
B runtime·rt0_go(SB)
DATA _rt0_arm_linux_lib_argc<>(SB)/4,$0
GLOBL _rt0_arm_linux_lib_argc<>(SB),NOPTR,$4
DATA _rt0_arm_linux_lib_argv<>(SB)/4,$0
GLOBL _rt0_arm_linux_lib_argv<>(SB),NOPTR,$4
TEXT _rt0_arm_linux1(SB),NOSPLIT,$-4
// We first need to detect the kernel ABI, and warn the user
// if the system only supports OABI
// The strategy here is to call some EABI syscall to see if
// SIGILL is received.
// To catch SIGILL, we have to first setup sigaction, this is
// a chicken-and-egg problem, because we can't do syscall if
// we don't know the kernel ABI... Oh, not really, we can do
// syscall in Thumb mode.
// Save argc and argv
MOVM.DB.W [R0-R1], (R13)
// Thumb mode OABI check disabled because there are some
// EABI systems that do not support Thumb execution.
// We can run on them except for this check!
// // set up sa_handler
// MOVW $bad_abi<>(SB), R0 // sa_handler
// MOVW $0, R1 // sa_flags
// MOVW $0, R2 // sa_restorer
// MOVW $0, R3 // sa_mask
// MOVM.DB.W [R0-R3], (R13)
// MOVW $4, R0 // SIGILL
// MOVW R13, R1 // sa
// SUB $16, R13
// MOVW R13, R2 // old_sa
// MOVW $8, R3 // c
// MOVW $174, R7 // sys_sigaction
// BL oabi_syscall<>(SB)
// do an EABI syscall
MOVW $20, R7 // sys_getpid
SWI $0 // this will trigger SIGILL on OABI systems
// MOVW $4, R0 // SIGILL
// MOVW R13, R1 // sa
// MOVW $0, R2 // old_sa
// MOVW $8, R3 // c
// MOVW $174, R7 // sys_sigaction
// SWI $0 // restore signal handler
// ADD $32, R13
B runtime·rt0_go(SB)
TEXT bad_abi<>(SB),NOSPLIT,$-4
// give diagnosis and exit
MOVW $2, R0 // stderr
MOVW $bad_abi_msg(SB), R1 // data
MOVW $45, R2 // len
MOVW $4, R7 // sys_write
BL oabi_syscall<>(SB)
MOVW $1, R0
MOVW $1, R7 // sys_exit
BL oabi_syscall<>(SB)
B 0(PC)
DATA bad_abi_msg+0x00(SB)/8, $"This pro"
DATA bad_abi_msg+0x08(SB)/8, $"gram can"
DATA bad_abi_msg+0x10(SB)/8, $" only be"
DATA bad_abi_msg+0x18(SB)/8, $" run on "
DATA bad_abi_msg+0x20(SB)/8, $"EABI ker"
DATA bad_abi_msg+0x28(SB)/4, $"nels"
DATA bad_abi_msg+0x2c(SB)/1, $0xa
GLOBL bad_abi_msg(SB), RODATA, $45
TEXT oabi_syscall<>(SB),NOSPLIT,$-4
ADD $1, R15, R4 // R15 is hardware PC
WORD $0xe12fff14 //BX (R4) // enter thumb mode
// TODO(minux): only supports little-endian CPUs
WORD $0x4770df01 // swi $1; bx lr
TEXT main(SB),NOSPLIT,$-4
MOVW $_rt0_arm_linux1(SB), R4
B (R4)
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