Please find submitted a patch for ARM memory barriers. This patch is
against qemu-2.12-rc2 but I do believe it should apply for anything from
2.11.x to current. (the code being patched was added in for 2.11 series.)
I found with qemu 2.11.x or newer that I would get an illegal instruction
error running some Intel binaries on my ARM chromebook. On investigation,
I found it was quitting on memory barriers.
qemu instruction:
mb $0x31
was translating as:
0x604050cc: 5bf07ff5 blpl #0x600250a8
After patch it gives:
0x604050cc: f57ff05b dmb ish
In short, I found INSN_DMB_ISH (memory barrier for ARMv7) appeared to be correct based on online docs, but due to some endian-related shenanigans it had to be byte-swapped to suit qemu; it appears INSN_DMB_MCR (memory barrier for ARMv6) also should be byte swapped (and this patch does so).
I have not checked for correctness of aarch64's barrier instruction.
Signed-off-by: Henry Wertz <address@hidden>
arm-mb.patch