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tcg/arm: Fix memory barrier encoding 

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.

Cc: qemu-stable@nongnu.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Henry Wertz <hwertz10@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Henry Wertz 2018-04-17 12:06:23 -10:00 committed by Richard Henderson
parent d103021269
commit 3f814b8037
1 changed files with 2 additions and 2 deletions
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4
tcg/arm/tcg-target.inc.c
View File

@ -159,8 +159,8 @@ typedef enum {
INSN_STRD_IMM = 0x004000f0,
INSN_STRD_REG = 0x000000f0,
INSN_DMB_ISH = 0x5bf07ff5,
INSN_DMB_MCR = 0xba0f07ee,
INSN_DMB_ISH = 0xf57ff05b,
INSN_DMB_MCR = 0xee070fba,
/* Architected nop introduced in v6k. */
/* ??? This is an MSR (imm) 0,0,0 insn. Anyone know if this