| // 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 $_rt0_arm_linux1(SB), R4 |
| B (R4) |
| |
| TEXT _rt0_arm_linux1(SB),NOSPLIT,$-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) |
| |
