From 068a6c7895607a6af6758ad18bace683f6b7499d Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Tue, 27 Oct 2009 01:14:33 -0400 Subject: [PATCH] ARM: allow proper single stepping of Thumb BL and BLX instructions Whenever an unconditional branch with the H bits set to 0b10 is met, the offset must be combined with the offset from the following opcode and not ignored like it is now. A comment in evaluate_b_bl_blx_thumb() suggests that the Thumb2 decoder would be a simpler solution. That might be true when single-stepping of Thumb2 code is implemented. But for now this appears to be the simplest solution to fix Thumb1 support. Signed-off-by: Nicolas Pitre Signed-off-by: David Brownell --- src/target/arm_simulator.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/src/target/arm_simulator.c b/src/target/arm_simulator.c index 646baea7..5af2c129 100644 --- a/src/target/arm_simulator.c +++ b/src/target/arm_simulator.c @@ -332,6 +332,18 @@ int arm_simulate_step_core(target_t *target, uint32_t *dry_run_pc, struct arm_si return ERROR_OK; } + + /* Deal with 32-bit BL/BLX */ + if ((opcode & 0xf800) == 0xf000) { + uint32_t high = instruction.info.b_bl_bx_blx.target_address; + retval = target_read_u16(target, current_pc+2, &opcode); + if (retval != ERROR_OK) + return retval; + retval = thumb_evaluate_opcode(opcode, current_pc, &instruction); + if (retval != ERROR_OK) + return retval; + instruction.info.b_bl_bx_blx.target_address += high; + } } /* examine instruction type */ -- 2.39.5