/** Write the Debug Status and Control Register (DSCR)
*
* same as CP14 c1
*
* \param arm11 Target state variable.
* \param dscr DSCR content
*
* \remarks This is a stand-alone function that executes the JTAG command queue.
*/
int arm11_write_DSCR(struct arm11_common * arm11, uint32_t dscr)
{
int retval;
retval = arm11_add_debug_SCAN_N(arm11, 0x01, ARM11_TAP_DEFAULT);
if (retval != ERROR_OK)
return retval;
arm11_add_IR(arm11, ARM11_EXTEST, ARM11_TAP_DEFAULT);
struct scan_field chain1_field;
arm11_setup_field(arm11, 32, &dscr, NULL, &chain1_field);
arm11_add_dr_scan_vc(1, &chain1_field, TAP_DRPAUSE);
CHECK_RETVAL(jtag_execute_queue());
JTAG_DEBUG("DSCR <= %08x (OLD %08x)",
(unsigned) dscr,
(unsigned) arm11->dscr);
arm11->dscr = dscr;
return ERROR_OK;
}
/** Write the Debug Status and Control Register (DSCR)
*
* same as CP14 c1
*
* \param arm11 Target state variable.
* \param dscr DSCR content
*
* \remarks This is a stand-alone function that executes the JTAG command queue.
*/
void arm11_write_DSCR(arm11_common_t * arm11, u32 dscr)
{
arm11_add_debug_SCAN_N(arm11, 0x01, -1);
arm11_add_IR(arm11, ARM11_EXTEST, -1);
scan_field_t chain1_field;
arm11_setup_field(arm11, 32, &dscr, NULL, &chain1_field);
arm11_add_dr_scan_vc(1, &chain1_field, TAP_DRPAUSE);
jtag_execute_queue();
JTAG_DEBUG("DSCR <= %08x (OLD %08x)", dscr, arm11->last_dscr);
arm11->last_dscr = dscr;
}
/** Read the Debug Status and Control Register (DSCR)
*
* same as CP14 c1
*
* \param arm11 Target state variable.
* \return DSCR content
*
* \remarks This is a stand-alone function that executes the JTAG command queue.
*/
u32 arm11_read_DSCR(arm11_common_t * arm11)
{
arm11_add_debug_SCAN_N(arm11, 0x01, -1);
arm11_add_IR(arm11, ARM11_INTEST, -1);
u32 dscr;
scan_field_t chain1_field;
arm11_setup_field(arm11, 32, NULL, &dscr, &chain1_field);
arm11_add_dr_scan_vc(1, &chain1_field, TAP_DRPAUSE);
jtag_execute_queue();
if (arm11->last_dscr != dscr)
JTAG_DEBUG("DSCR = %08x (OLD %08x)", dscr, arm11->last_dscr);
arm11->last_dscr = dscr;
return dscr;
}
/** Apply reads and writes to scan chain 7
*
* \see struct arm11_sc7_action
*
* \param arm11 Target state variable.
* \param actions A list of read and/or write instructions
* \param count Number of instructions in the list.
*
*/
int arm11_sc7_run(struct arm11_common * arm11, struct arm11_sc7_action * actions, size_t count)
{
int retval;
retval = arm11_add_debug_SCAN_N(arm11, 0x07, ARM11_TAP_DEFAULT);
if (retval != ERROR_OK)
return retval;
arm11_add_IR(arm11, ARM11_EXTEST, ARM11_TAP_DEFAULT);
struct scan_field chain7_fields[3];
uint8_t nRW;
uint32_t DataOut;
uint8_t AddressOut;
uint8_t Ready;
uint32_t DataIn;
uint8_t AddressIn;
arm11_setup_field(arm11, 1, &nRW, &Ready, chain7_fields + 0);
arm11_setup_field(arm11, 32, &DataOut, &DataIn, chain7_fields + 1);
arm11_setup_field(arm11, 7, &AddressOut, &AddressIn, chain7_fields + 2);
for (size_t i = 0; i < count + 1; i++)
{
if (i < count)
{
nRW = actions[i].write ? 1 : 0;
DataOut = actions[i].value;
AddressOut = actions[i].address;
}
else
{
nRW = 1;
DataOut = 0;
AddressOut = 0;
}
/* Timeout here so we don't get stuck. */
int i = 0;
while (1)
{
JTAG_DEBUG("SC7 <= c%-3d Data %08x %s",
(unsigned) AddressOut,
(unsigned) DataOut,
nRW ? "write" : "read");
arm11_add_dr_scan_vc(ARRAY_SIZE(chain7_fields),
chain7_fields, TAP_DRPAUSE);
CHECK_RETVAL(jtag_execute_queue());
/* 'nRW' is 'Ready' on read out */
if (Ready)
break;
long long then = 0;
if (i == 1000)
{
then = timeval_ms();
}
if (i >= 1000)
{
if ((timeval_ms()-then) > 1000)
{
LOG_WARNING("Timeout (1000ms) waiting for instructions to complete");
return ERROR_FAIL;
}
}
i++;
}
if (!nRW)
JTAG_DEBUG("SC7 => Data %08x", (unsigned) DataIn);
if (i > 0)
{
if (actions[i - 1].address != AddressIn)
{
LOG_WARNING("Scan chain 7 shifted out unexpected address");
}
if (!actions[i - 1].write)
{
actions[i - 1].value = DataIn;
}
else
{
if (actions[i - 1].value != DataIn)
{
LOG_WARNING("Scan chain 7 shifted out unexpected data");
}
}
}
}
return ERROR_OK;
}
/** Cleanup after ITR/DTR operations
* from the arm11_run_instr... group of functions
*
* Put arm11_run_instr_data_prepare() and arm11_run_instr_data_finish()
* around a block of arm11_run_instr_... calls.
*
* Any IDLE can lead to an instruction execution when
* scan chains 4 or 5 are selected and the IR holds
* INTEST or EXTEST. So we must disable that before
* any following activities lead to an IDLE.
*
* \param arm11 Target state variable.
*
*/
int arm11_run_instr_data_finish(struct arm11_common * arm11)
{
return arm11_add_debug_SCAN_N(arm11, 0x00, ARM11_TAP_DEFAULT);
}
/** Prepare the stage for ITR/DTR operations
* from the arm11_run_instr... group of functions.
*
* Put arm11_run_instr_data_prepare() and arm11_run_instr_data_finish()
* around a block of arm11_run_instr_... calls.
*
* Select scan chain 5 to allow quick access to DTR. When scan
* chain 4 is needed to put in a register the ITRSel instruction
* shortcut is used instead of actually changing the Scan_N
* register.
*
* \param arm11 Target state variable.
*
*/
int arm11_run_instr_data_prepare(struct arm11_common * arm11)
{
return arm11_add_debug_SCAN_N(arm11, 0x05, ARM11_TAP_DEFAULT);
}
/**
* Save processor state. This is called after a HALT instruction
* succeeds, and on other occasions the processor enters debug mode
* (breakpoint, watchpoint, etc). Caller has updated arm11->dscr.
*/
static int arm11_debug_entry(struct arm11_common *arm11)
{
int retval;
arm11->arm.target->state = TARGET_HALTED;
arm_dpm_report_dscr(arm11->arm.dpm, arm11->dscr);
/* REVISIT entire cache should already be invalid !!! */
register_cache_invalidate(arm11->arm.core_cache);
/* See e.g. ARM1136 TRM, "14.8.4 Entering Debug state" */
/* maybe save wDTR (pending DCC write to debug SW, e.g. libdcc) */
arm11->is_wdtr_saved = !!(arm11->dscr & DSCR_DTR_TX_FULL);
if (arm11->is_wdtr_saved)
{
arm11_add_debug_SCAN_N(arm11, 0x05, ARM11_TAP_DEFAULT);
arm11_add_IR(arm11, ARM11_INTEST, ARM11_TAP_DEFAULT);
struct scan_field chain5_fields[3];
arm11_setup_field(arm11, 32, NULL,
&arm11->saved_wdtr, chain5_fields + 0);
arm11_setup_field(arm11, 1, NULL, NULL, chain5_fields + 1);
arm11_setup_field(arm11, 1, NULL, NULL, chain5_fields + 2);
arm11_add_dr_scan_vc(arm11->arm.target->tap, ARRAY_SIZE(chain5_fields), chain5_fields, TAP_DRPAUSE);
}
/* DSCR: set the Execute ARM instruction enable bit.
*
* ARM1176 spec says this is needed only for wDTR/rDTR's "ITR mode",
* but not to issue ITRs(?). The ARMv7 arch spec says it's required
* for executing instructions via ITR.
*/
CHECK_RETVAL(arm11_write_DSCR(arm11, DSCR_ITR_EN | arm11->dscr));
/* From the spec:
Before executing any instruction in debug state you have to drain the write buffer.
This ensures that no imprecise Data Aborts can return at a later point:*/
/** \todo TODO: Test drain write buffer. */
#if 0
while (1)
{
/* MRC p14,0,R0,c5,c10,0 */
// arm11_run_instr_no_data1(arm11, /*0xee150e1a*/0xe320f000);
/* mcr 15, 0, r0, cr7, cr10, {4} */
arm11_run_instr_no_data1(arm11, 0xee070f9a);
uint32_t dscr = arm11_read_DSCR(arm11);
LOG_DEBUG("DRAIN, DSCR %08x", dscr);
if (dscr & ARM11_DSCR_STICKY_IMPRECISE_DATA_ABORT)
{
arm11_run_instr_no_data1(arm11, 0xe320f000);
dscr = arm11_read_DSCR(arm11);
LOG_DEBUG("DRAIN, DSCR %08x (DONE)", dscr);
break;
}
}
#endif
/* Save registers.
*
* NOTE: ARM1136 TRM suggests saving just R0 here now, then
* CPSR and PC after the rDTR stuff. We do it all at once.
*/
retval = arm_dpm_read_current_registers(&arm11->dpm);
if (retval != ERROR_OK)
LOG_ERROR("DPM REG READ -- fail");
retval = arm11_run_instr_data_prepare(arm11);
if (retval != ERROR_OK)
return retval;
/* maybe save rDTR (pending DCC read from debug SW, e.g. libdcc) */
arm11->is_rdtr_saved = !!(arm11->dscr & DSCR_DTR_RX_FULL);
if (arm11->is_rdtr_saved)
{
/* MRC p14,0,R0,c0,c5,0 (move rDTR -> r0 (-> wDTR -> local var)) */
retval = arm11_run_instr_data_from_core_via_r0(arm11,
0xEE100E15, &arm11->saved_rdtr);
if (retval != ERROR_OK)
return retval;
}
/* REVISIT Now that we've saved core state, there's may also
* be MMU and cache state to care about ...
*/
if (arm11->simulate_reset_on_next_halt)
{
arm11->simulate_reset_on_next_halt = false;
LOG_DEBUG("Reset c1 Control Register");
/* Write 0 (reset value) to Control register 0 to disable MMU/Cache etc. */
/* MCR p15,0,R0,c1,c0,0 */
retval = arm11_run_instr_data_to_core_via_r0(arm11, 0xee010f10, 0);
if (retval != ERROR_OK)
return retval;
}
if (arm11->arm.target->debug_reason == DBG_REASON_WATCHPOINT) {
uint32_t wfar;
/* MRC p15, 0, <Rd>, c6, c0, 1 ; Read WFAR */
retval = arm11_run_instr_data_from_core_via_r0(arm11,
ARMV4_5_MRC(15, 0, 0, 6, 0, 1),
&wfar);
if (retval != ERROR_OK)
return retval;
arm_dpm_report_wfar(arm11->arm.dpm, wfar);
}
retval = arm11_run_instr_data_finish(arm11);
if (retval != ERROR_OK)
return retval;
return ERROR_OK;
}
/**
* Restore processor state. This is called in preparation for
* the RESTART function.
*/
static int arm11_leave_debug_state(struct arm11_common *arm11, bool bpwp)
{
int retval;
/* See e.g. ARM1136 TRM, "14.8.5 Leaving Debug state" */
/* NOTE: the ARM1136 TRM suggests restoring all registers
* except R0/PC/CPSR right now. Instead, we do them all
* at once, just a bit later on.
*/
/* REVISIT once we start caring about MMU and cache state,
* address it here ...
*/
/* spec says clear wDTR and rDTR; we assume they are clear as
otherwise our programming would be sloppy */
{
CHECK_RETVAL(arm11_read_DSCR(arm11));
if (arm11->dscr & (DSCR_DTR_RX_FULL | DSCR_DTR_TX_FULL))
{
/*
The wDTR/rDTR two registers that are used to send/receive data to/from
the core in tandem with corresponding instruction codes that are
written into the core. The RDTR FULL/WDTR FULL flag indicates that the
registers hold data that was written by one side (CPU or JTAG) and not
read out by the other side.
*/
LOG_ERROR("wDTR/rDTR inconsistent (DSCR %08x)",
(unsigned) arm11->dscr);
return ERROR_FAIL;
}
}
/* maybe restore original wDTR */
if (arm11->is_wdtr_saved)
{
retval = arm11_run_instr_data_prepare(arm11);
if (retval != ERROR_OK)
return retval;
/* MCR p14,0,R0,c0,c5,0 */
retval = arm11_run_instr_data_to_core_via_r0(arm11,
0xee000e15, arm11->saved_wdtr);
if (retval != ERROR_OK)
return retval;
retval = arm11_run_instr_data_finish(arm11);
if (retval != ERROR_OK)
return retval;
}
/* restore CPSR, PC, and R0 ... after flushing any modified
* registers.
*/
CHECK_RETVAL(arm_dpm_write_dirty_registers(&arm11->dpm, bpwp));
CHECK_RETVAL(arm11_bpwp_flush(arm11));
register_cache_invalidate(arm11->arm.core_cache);
/* restore DSCR */
CHECK_RETVAL(arm11_write_DSCR(arm11, arm11->dscr));
/* maybe restore rDTR */
if (arm11->is_rdtr_saved)
{
arm11_add_debug_SCAN_N(arm11, 0x05, ARM11_TAP_DEFAULT);
arm11_add_IR(arm11, ARM11_EXTEST, ARM11_TAP_DEFAULT);
struct scan_field chain5_fields[3];
uint8_t Ready = 0; /* ignored */
uint8_t Valid = 0; /* ignored */
arm11_setup_field(arm11, 32, &arm11->saved_rdtr,
NULL, chain5_fields + 0);
arm11_setup_field(arm11, 1, &Ready, NULL, chain5_fields + 1);
arm11_setup_field(arm11, 1, &Valid, NULL, chain5_fields + 2);
arm11_add_dr_scan_vc(arm11->arm.target->tap, ARRAY_SIZE(chain5_fields), chain5_fields, TAP_DRPAUSE);
}
/* now processor is ready to RESTART */
return ERROR_OK;
}
/* talk to the target and set things up */
static int arm11_examine(struct target *target)
{
int retval;
char *type;
struct arm11_common *arm11 = target_to_arm11(target);
uint32_t didr, device_id;
uint8_t implementor;
/* FIXME split into do-first-time and do-every-time logic ... */
/* check IDCODE */
arm11_add_IR(arm11, ARM11_IDCODE, ARM11_TAP_DEFAULT);
struct scan_field idcode_field;
arm11_setup_field(arm11, 32, NULL, &device_id, &idcode_field);
arm11_add_dr_scan_vc(arm11->arm.target->tap, 1, &idcode_field, TAP_DRPAUSE);
/* check DIDR */
arm11_add_debug_SCAN_N(arm11, 0x00, ARM11_TAP_DEFAULT);
arm11_add_IR(arm11, ARM11_INTEST, ARM11_TAP_DEFAULT);
struct scan_field chain0_fields[2];
arm11_setup_field(arm11, 32, NULL, &didr, chain0_fields + 0);
arm11_setup_field(arm11, 8, NULL, &implementor, chain0_fields + 1);
arm11_add_dr_scan_vc(arm11->arm.target->tap, ARRAY_SIZE(chain0_fields), chain0_fields, TAP_IDLE);
CHECK_RETVAL(jtag_execute_queue());
/* assume the manufacturer id is ok; check the part # */
switch ((device_id >> 12) & 0xFFFF)
{
case 0x7B36:
type = "ARM1136";
break;
case 0x7B37:
type = "ARM11 MPCore";
break;
case 0x7B56:
type = "ARM1156";
break;
case 0x7B76:
arm11->arm.core_type = ARM_MODE_MON;
/* NOTE: could default arm11->hardware_step to true */
type = "ARM1176";
break;
default:
LOG_ERROR("unexpected ARM11 ID code");
return ERROR_FAIL;
}
LOG_INFO("found %s", type);
/* unlikely this could ever fail, but ... */
switch ((didr >> 16) & 0x0F) {
case ARM11_DEBUG_V6:
case ARM11_DEBUG_V61: /* supports security extensions */
break;
default:
LOG_ERROR("Only ARM v6 and v6.1 debug supported.");
return ERROR_FAIL;
}
arm11->brp = ((didr >> 24) & 0x0F) + 1;
/** \todo TODO: reserve one brp slot if we allow breakpoints during step */
arm11->free_brps = arm11->brp;
LOG_DEBUG("IDCODE %08" PRIx32 " IMPLEMENTOR %02x DIDR %08" PRIx32,
device_id, implementor, didr);
/* as a side-effect this reads DSCR and thus
* clears the ARM11_DSCR_STICKY_PRECISE_DATA_ABORT / Sticky Precise Data Abort Flag
* as suggested by the spec.
*/
retval = arm11_check_init(arm11);
if (retval != ERROR_OK)
return retval;
/* Build register cache "late", after target_init(), since we
* want to know if this core supports Secure Monitor mode.
*/
if (!target_was_examined(target))
CHECK_RETVAL(arm11_dpm_init(arm11, didr));
/* ETM on ARM11 still uses original scanchain 6 access mode */
if (arm11->arm.etm && !target_was_examined(target)) {
*register_get_last_cache_p(&target->reg_cache) =
etm_build_reg_cache(target, &arm11->jtag_info,
arm11->arm.etm);
CHECK_RETVAL(etm_setup(target));
}
target_set_examined(target);
return ERROR_OK;
}
/** Apply reads and writes to scan chain 7
*
* \see arm11_sc7_action_t
*
* \param arm11 Target state variable.
* \param actions A list of read and/or write instructions
* \param count Number of instructions in the list.
*
*/
void arm11_sc7_run(arm11_common_t * arm11, arm11_sc7_action_t * actions, size_t count)
{
arm11_add_debug_SCAN_N(arm11, 0x07, -1);
arm11_add_IR(arm11, ARM11_EXTEST, -1);
scan_field_t chain7_fields[3];
u8 nRW;
u32 DataOut;
u8 AddressOut;
u8 Ready;
u32 DataIn;
u8 AddressIn;
arm11_setup_field(arm11, 1, &nRW, &Ready, chain7_fields + 0);
arm11_setup_field(arm11, 32, &DataOut, &DataIn, chain7_fields + 1);
arm11_setup_field(arm11, 7, &AddressOut, &AddressIn, chain7_fields + 2);
{size_t i;
for (i = 0; i < count + 1; i++)
{
if (i < count)
{
nRW = actions[i].write ? 1 : 0;
DataOut = actions[i].value;
AddressOut = actions[i].address;
}
else
{
nRW = 0;
DataOut = 0;
AddressOut = 0;
}
do
{
JTAG_DEBUG("SC7 <= Address %02x Data %08x nRW %d", AddressOut, DataOut, nRW);
arm11_add_dr_scan_vc(asizeof(chain7_fields), chain7_fields, TAP_DRPAUSE);
jtag_execute_queue();
JTAG_DEBUG("SC7 => Address %02x Data %08x Ready %d", AddressIn, DataIn, Ready);
}
while (!Ready); /* 'nRW' is 'Ready' on read out */
if (i > 0)
{
if (actions[i - 1].address != AddressIn)
{
LOG_WARNING("Scan chain 7 shifted out unexpected address");
}
if (!actions[i - 1].write)
{
actions[i - 1].value = DataIn;
}
else
{
if (actions[i - 1].value != DataIn)
{
LOG_WARNING("Scan chain 7 shifted out unexpected data");
}
}
}
}}
{size_t i;
for (i = 0; i < count; i++)
{
JTAG_DEBUG("SC7 %02d: %02x %s %08x", i, actions[i].address, actions[i].write ? "<=" : "=>", actions[i].value);
}}
}
/** Cleanup after ITR/DTR operations
* from the arm11_run_instr... group of functions
*
* Put arm11_run_instr_data_prepare() and arm11_run_instr_data_finish()
* around a block of arm11_run_instr_... calls.
*
* Any IDLE can lead to an instruction execution when
* scan chains 4 or 5 are selected and the IR holds
* INTEST or EXTEST. So we must disable that before
* any following activities lead to an IDLE.
*
* \param arm11 Target state variable.
*
*/
void arm11_run_instr_data_finish(arm11_common_t * arm11)
{
arm11_add_debug_SCAN_N(arm11, 0x00, -1);
}
/** Prepare the stage for ITR/DTR operations
* from the arm11_run_instr... group of functions.
*
* Put arm11_run_instr_data_prepare() and arm11_run_instr_data_finish()
* around a block of arm11_run_instr_... calls.
*
* Select scan chain 5 to allow quick access to DTR. When scan
* chain 4 is needed to put in a register the ITRSel instruction
* shortcut is used instead of actually changing the Scan_N
* register.
*
* \param arm11 Target state variable.
*
*/
void arm11_run_instr_data_prepare(arm11_common_t * arm11)
{
arm11_add_debug_SCAN_N(arm11, 0x05, -1);
}
