void arm9tdmi_change_to_arm(target_t *target, u32 *r0, u32 *pc)
{
int retval = ERROR_OK;
/* get pointers to arch-specific information */
armv4_5_common_t *armv4_5 = target->arch_info;
arm7_9_common_t *arm7_9 = armv4_5->arch_info;
arm_jtag_t *jtag_info = &arm7_9->jtag_info;
/* save r0 before using it and put system in ARM state
* to allow common handling of ARM and THUMB debugging */
/* fetch STR r0, [r0] */
arm9tdmi_clock_out(jtag_info, ARMV4_5_T_STR(0, 0), 0, NULL, 0);
arm9tdmi_clock_out(jtag_info, ARMV4_5_T_NOP, 0, NULL, 0);
arm9tdmi_clock_out(jtag_info, ARMV4_5_T_NOP, 0, NULL, 0);
/* STR r0, [r0] in Memory */
arm9tdmi_clock_out(jtag_info, ARMV4_5_T_NOP, 0, r0, 0);
/* MOV r0, r15 fetched, STR in Decode */
arm9tdmi_clock_out(jtag_info, ARMV4_5_T_MOV(0, 15), 0, NULL, 0);
arm9tdmi_clock_out(jtag_info, ARMV4_5_T_NOP, 0, NULL, 0);
arm9tdmi_clock_out(jtag_info, ARMV4_5_T_STR(0, 0), 0, NULL, 0);
arm9tdmi_clock_out(jtag_info, ARMV4_5_T_NOP, 0, NULL, 0);
arm9tdmi_clock_out(jtag_info, ARMV4_5_T_NOP, 0, NULL, 0);
/* nothing fetched, STR r0, [r0] in Memory */
arm9tdmi_clock_out(jtag_info, ARMV4_5_T_NOP, 0, pc, 0);
/* use pc-relative LDR to clear r0[1:0] (for switch to ARM mode) */
arm9tdmi_clock_out(jtag_info, ARMV4_5_T_LDR_PCREL(0), 0, NULL, 0);
/* LDR in Decode */
arm9tdmi_clock_out(jtag_info, ARMV4_5_T_NOP, 0, NULL, 0);
/* LDR in Execute */
arm9tdmi_clock_out(jtag_info, ARMV4_5_T_NOP, 0, NULL, 0);
/* LDR in Memory (to account for interlock) */
arm9tdmi_clock_out(jtag_info, ARMV4_5_T_NOP, 0, NULL, 0);
/* fetch BX */
arm9tdmi_clock_out(jtag_info, ARMV4_5_T_BX(0), 0, NULL, 0);
/* NOP fetched, BX in Decode, MOV in Execute */
arm9tdmi_clock_out(jtag_info, ARMV4_5_T_NOP, 0, NULL, 0);
/* NOP fetched, BX in Execute (1) */
arm9tdmi_clock_out(jtag_info, ARMV4_5_T_NOP, 0, NULL, 0);
if((retval = jtag_execute_queue()) != ERROR_OK)
{
return;
}
/* fix program counter:
* MOV r0, r15 was the 5th instruction (+8)
* reading PC in Thumb state gives address of instruction + 4
*/
*pc -= 0xc;
}
static void arm7tdmi_change_to_arm(struct target *target,
uint32_t *r0, uint32_t *pc)
{
struct arm7_9_common *arm7_9 = target_to_arm7_9(target);
struct arm_jtag *jtag_info = &arm7_9->jtag_info;
/* save r0 before using it and put system in ARM state
* to allow common handling of ARM and THUMB debugging */
/* fetch STR r0, [r0] */
arm7tdmi_clock_out(jtag_info, ARMV4_5_T_STR(0, 0), NULL, 0);
arm7tdmi_clock_out(jtag_info, ARMV4_5_T_NOP, NULL, 0);
arm7tdmi_clock_out(jtag_info, ARMV4_5_T_NOP, NULL, 0);
/* nothing fetched, STR r0, [r0] in Execute (2) */
arm7tdmi_clock_data_in(jtag_info, r0);
/* MOV r0, r15 fetched, STR in Decode */
arm7tdmi_clock_out(jtag_info, ARMV4_5_T_MOV(0, 15), NULL, 0);
arm7tdmi_clock_out(jtag_info, ARMV4_5_T_STR(0, 0), NULL, 0);
arm7tdmi_clock_out(jtag_info, ARMV4_5_T_NOP, NULL, 0);
arm7tdmi_clock_out(jtag_info, ARMV4_5_T_NOP, NULL, 0);
/* nothing fetched, STR r0, [r0] in Execute (2) */
arm7tdmi_clock_data_in(jtag_info, pc);
/* use pc-relative LDR to clear r0[1:0] (for switch to ARM mode) */
arm7tdmi_clock_out(jtag_info, ARMV4_5_T_LDR_PCREL(0), NULL, 0);
arm7tdmi_clock_out(jtag_info, ARMV4_5_T_NOP, NULL, 0);
arm7tdmi_clock_out(jtag_info, ARMV4_5_T_NOP, NULL, 0);
/* nothing fetched, data for LDR r0, [PC, #0] */
arm7tdmi_clock_out(jtag_info, 0x0, NULL, 0);
/* nothing fetched, data from previous cycle is written to register */
arm7tdmi_clock_out(jtag_info, ARMV4_5_T_NOP, NULL, 0);
/* fetch BX */
arm7tdmi_clock_out(jtag_info, ARMV4_5_T_BX(0), NULL, 0);
/* NOP fetched, BX in Decode, MOV in Execute */
arm7tdmi_clock_out(jtag_info, ARMV4_5_T_NOP, NULL, 0);
/* NOP fetched, BX in Execute (1) */
arm7tdmi_clock_out(jtag_info, ARMV4_5_T_NOP, NULL, 0);
jtag_execute_queue();
/* fix program counter:
* MOV r0, r15 was the 4th instruction (+6)
* reading PC in Thumb state gives address of instruction + 4
*/
*pc -= 0xa;
}
