From 4f3c3dbb370a8c0c8b66710c5d0c2854c1bab4f5 Mon Sep 17 00:00:00 2001 From: Nick Clifton Date: Tue, 6 Mar 2001 22:33:47 +0000 Subject: Fix BLX(1) for Thumb --- sim/arm/ChangeLog | 6 ++++++ sim/arm/thumbemu.c | 23 ++++++++++++++++++----- 2 files changed, 24 insertions(+), 5 deletions(-) (limited to 'sim') diff --git a/sim/arm/ChangeLog b/sim/arm/ChangeLog index fd11ec1..d3d5b1c 100644 --- a/sim/arm/ChangeLog +++ b/sim/arm/ChangeLog @@ -1,3 +1,9 @@ +2001-03-06 Nick Clifton + + * thumbemu.c (ARMul_ThumbDecode): Delete label bo_blx2. + Compute destination address of BLX(1) instruction by + taking bit 1 from PC and not from bit 0 of the offset. + 2001-02-27 Nick Clifton * armvirt.c (GetWord): Add new parameter - check - to enable or diff --git a/sim/arm/thumbemu.c b/sim/arm/thumbemu.c index 3351c2f..4f00733 100644 --- a/sim/arm/thumbemu.c +++ b/sim/arm/thumbemu.c @@ -481,7 +481,6 @@ tdstate ARMul_ThumbDecode (state, pc, tinstr, ainstr) } /* Drop through. */ - do_blx2: /* BLX instruction 2 */ /* Format 19 */ /* There is no single ARM instruction equivalent for this instruction. Also, it should only ever be matched with the @@ -514,17 +513,31 @@ tdstate ARMul_ThumbDecode (state, pc, tinstr, ainstr) |((tinstr & (1 << 10)) ? 0xFF800000 : 0)); valid = t_branch; /* in-case we don't have the 2nd half */ tinstr = next_instr; /* move the instruction down */ + pc += 2; /* point the pc at the 2nd half */ if (((tinstr & 0xF800) >> 11) != 31) { if (((tinstr & 0xF800) >> 11) == 29) { - pc += 2; - goto do_blx2; + ARMword tmp = (pc + 2); + + /* Bit one of the destination address comes from bit one of the + address of the first (H == 10) half of the instruction, not + from the offset in the instruction. */ + state->Reg[15] = ((state->Reg[14] + + ((tinstr & 0x07FE) << 1) + + ((pc - 2) & 2)) + & 0xFFFFFFFC); + CLEART; + state->Reg[14] = (tmp | 1); + valid = t_branch; + FLUSHPIPE; } - break; /* exit, since not correct instruction */ + else + /* Exit, since not correct instruction. */ + pc -= 2; + break; } /* else we fall through to process the second half of the BL */ - pc += 2; /* point the pc at the 2nd half */ case 31: /* BL instruction 2 */ /* Format 19 */ /* There is no single ARM instruction equivalent for this -- cgit v1.1