runtime: remove OABI check from ARM startup The code in question is trying to print a nice error message when a Go EABI binary runs on an OABI machine. Unfortunately, the only way to do that is to use ARM Thumb instructions, which we otherwise don't use. There exist ARM EABI machines that do not support Thumb. We could run on them if not for this OABI check, so disable it. Fixes #5685. R=golang-dev, minux.ma CC=golang-dev https://golang.org/cl/13234050
diff --git a/src/pkg/runtime/rt0_linux_arm.s b/src/pkg/runtime/rt0_linux_arm.s index 63133e9..309fa2f 100644 --- a/src/pkg/runtime/rt0_linux_arm.s +++ b/src/pkg/runtime/rt0_linux_arm.s
@@ -22,31 +22,36 @@ // Save argc and argv MOVM.DB.W [R0-R1], (R13) - // 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) + + // 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 + // 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 SUB $4, R13 // fake a stack frame for runtime·setup_auxv BL runtime·setup_auxv(SB)