diff --git a/src/target/arm11.c b/src/target/arm11.c index 5f1607396..cbe4d4503 100644 --- a/src/target/arm11.c +++ b/src/target/arm11.c @@ -418,11 +418,33 @@ static uint32_t arm11_nextpc(struct arm11_common *arm11, int current, uint32_t a { void *value = arm11->arm.pc->value; - if (!current) - buf_set_u32(value, 0, 32, address); - else + /* use the current program counter */ + if (current) address = buf_get_u32(value, 0, 32); + /* Make sure that the gdb thumb fixup does not + * kill the return address + */ + switch (arm11->arm.core_state) { + case ARM_STATE_ARM: + address &= 0xFFFFFFFC; + break; + case ARM_STATE_THUMB: + /* When the return address is loaded into PC + * bit 0 must be 1 to stay in Thumb state + */ + address |= 0x1; + break; + + /* catch-all for JAZELLE and THUMB_EE */ + default: + break; + } + + buf_set_u32(value, 0, 32, address); + arm11->arm.pc->dirty = 1; + arm11->arm.pc->valid = 1; + return address; } diff --git a/src/target/arm_dpm.c b/src/target/arm_dpm.c index e9dd6303d..8ad6575cf 100644 --- a/src/target/arm_dpm.c +++ b/src/target/arm_dpm.c @@ -228,6 +228,18 @@ static int dpm_write_reg(struct arm_dpm *dpm, struct reg *r, unsigned regnum) return retval; } +/** + * Write to program counter and switch the core state (arm/thumb) according to + * the address. + */ +static int dpm_write_pc_core_state(struct arm_dpm *dpm, struct reg *r) +{ + uint32_t value = buf_get_u32(r->value, 0, 32); + + /* read r0 from DCC; then "BX r0" */ + return dpm->instr_write_data_r0(dpm, ARMV4_5_BX(0), value); +} + /** * Read basic registers of the the current context: R0 to R15, and CPSR; * sets the core mode (such as USR or IRQ) and state (such as ARM or Thumb). @@ -465,6 +477,19 @@ int arm_dpm_write_dirty_registers(struct arm_dpm *dpm, bool bpwp) goto done; arm->cpsr->dirty = false; + /* restore the PC, make sure to also switch the core state + * to whatever it was set to with "arm core_state" command. + * target code will have set PC to an appropriate resume address. + */ + retval = dpm_write_pc_core_state(dpm, arm->pc); + if (retval != ERROR_OK) + goto done; + /* on Cortex-A5 (as found on NXP VF610 SoC), BX instruction + * executed in debug state doesn't appear to set the PC, + * explicitly set it with a "MOV pc, r0". This doesn't influence + * CPSR on Cortex-A9 so it should be OK. Maybe due to different + * debug version? + */ retval = dpm_write_reg(dpm, arm->pc, 15); if (retval != ERROR_OK) goto done;