diff options
Diffstat (limited to 'ports/sysdeps/arm/sysdep.h')
| -rw-r--r-- | ports/sysdeps/arm/sysdep.h | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/ports/sysdeps/arm/sysdep.h b/ports/sysdeps/arm/sysdep.h index 4a7a13f6fb..4917805857 100644 --- a/ports/sysdeps/arm/sysdep.h +++ b/ports/sysdeps/arm/sysdep.h @@ -210,6 +210,48 @@ cfi_restore_state # endif /* ARCH_HAS_HARD_TP */ +# ifndef ARM_SFI_MACROS +# define ARM_SFI_MACROS 1 +/* This assembly macro is prepended to any load/store instruction, + pulling the base register out of the addressing mode syntax and + making it the first operand of the macro. For example: + ldr r0, [r1] + becomes: + sfi_breg r1, ldr r0, [\B] + The \B stands in for the base register that is the first operand + to the macro, so we can avoid error-prone repetition of the base + register in two places on the line. + + This is used for all memory access through a base register other + than PC or SP. It's intended to support SFI schemes such as + Native Client, where the OS will enforce that all load/store + instructions use a special form. In any such configuration, + another sysdep.h file will have defined ARM_SFI_MACROS and + provided its own assembly macros with the same interface. */ + + .macro sfi_breg basereg, insn, operands:vararg + .macro _sfi_breg_doit B + \insn \operands + .endm + _sfi_breg_doit \basereg + .purgem _sfi_breg_doit + .endm + +/* This assembly macro replaces the "pld" instruction. + The syntax: + sfi_pld REGISTER, #OFFSET + is exactly equivalent to: + sfi_breg REGISTER, pld [\B, #OFFSET] + (and ", #OFFSET" is optional). We have a separate macro + only to work around a bug in GAS versions prior to 2.23.2, + that misparses the sfi_breg macro expansion in this case. */ + + .macro sfi_pld basereg, offset=#0 + pld [\basereg, \offset] + .endm + +# endif + #endif /* __ASSEMBLER__ */ /* This number is the offset from the pc at the current location. */ |