[committed] microMIPS: Add SYSCALL instruction decoding
Commit Message
Fix a bug with commit 4cc0665f24bb ("microMIPS support"),
<https://sourceware.org/ml/gdb-patches/2012-05/msg00724.html>, and add
missing microMIPS SYSCALL instruction decoding needed to determine the
location to put a breakpoint at when single-stepping though a syscall.
gdb/
* mips-tdep.c (micromips_next_pc): Add SYSCALL instruction
decoding.
---
gdb/mips-tdep.c | 30 ++++++++++++++++++++++++------
1 file changed, 24 insertions(+), 6 deletions(-)
gdb-umips-syscall-next-pc.diff
===================================================================
@@ -1898,12 +1898,30 @@ micromips_next_pc (struct regcache *regc
switch (micromips_op (insn >> 16))
{
case 0x00: /* POOL32A: bits 000000 */
- if (b0s6_op (insn) == 0x3c
- /* POOL32Axf: bits 000000 ... 111100 */
- && (b6s10_ext (insn) & 0x2bf) == 0x3c)
- /* JALR, JALR.HB: 000000 000x111100 111100 */
- /* JALRS, JALRS.HB: 000000 010x111100 111100 */
- pc = regcache_raw_get_signed (regcache, b0s5_reg (insn >> 16));
+ switch (b0s6_op (insn))
+ {
+ case 0x3c: /* POOL32Axf: bits 000000 ... 111100 */
+ switch (b6s10_ext (insn))
+ {
+ case 0x3c: /* JALR: 000000 0000111100 111100 */
+ case 0x7c: /* JALR.HB: 000000 0001111100 111100 */
+ case 0x13c: /* JALRS: 000000 0100111100 111100 */
+ case 0x17c: /* JALRS.HB: 000000 0101111100 111100 */
+ pc = regcache_raw_get_signed (regcache,
+ b0s5_reg (insn >> 16));
+ break;
+ case 0x22d: /* SYSCALL: 000000 1000101101 111100 */
+ {
+ struct gdbarch_tdep *tdep;
+
+ tdep = gdbarch_tdep (gdbarch);
+ if (tdep->syscall_next_pc != NULL)
+ pc = tdep->syscall_next_pc (get_current_frame ());
+ }
+ break;
+ }
+ break;
+ }
break;
case 0x10: /* POOL32I: bits 010000 */