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-rw-r--r--src/target/arm11.c28
-rw-r--r--src/target/arm11_dbgtap.c43
2 files changed, 43 insertions, 28 deletions
diff --git a/src/target/arm11.c b/src/target/arm11.c
index 7b29f53e..7c747c06 100644
--- a/src/target/arm11.c
+++ b/src/target/arm11.c
@@ -1012,27 +1012,25 @@ static int arm11_write_memory_inner(struct target *target,
}
case 4: {
+ /* increment: STC p14,c5,[R0],#4 */
+ /* no increment: STC p14,c5,[R0]*/
uint32_t instr = !no_increment ? 0xeca05e01 : 0xed805e00;
/** \todo TODO: buffer cast to uint32_t* causes alignment warnings */
uint32_t *words = (uint32_t*)buffer;
+ /* "burst" here just means trusting each instruction executes
+ * fully before we run the next one: per-word roundtrips, to
+ * check the Ready flag, are not used.
+ */
if (!burst)
- {
- /* STC p14,c5,[R0],#4 */
- /* STC p14,c5,[R0]*/
- retval = arm11_run_instr_data_to_core(arm11, instr, words, count);
- if (retval != ERROR_OK)
- return retval;
- }
+ retval = arm11_run_instr_data_to_core(arm11,
+ instr, words, count);
else
- {
- /* STC p14,c5,[R0],#4 */
- /* STC p14,c5,[R0]*/
- retval = arm11_run_instr_data_to_core_noack(arm11, instr, words, count);
- if (retval != ERROR_OK)
- return retval;
- }
+ retval = arm11_run_instr_data_to_core_noack(arm11,
+ instr, words, count);
+ if (retval != ERROR_OK)
+ return retval;
break;
}
@@ -1309,7 +1307,7 @@ static const struct command_registration arm11_mw_command_handlers[] = {
.name = "burst",
.handler = &arm11_handle_bool_memwrite_burst,
.mode = COMMAND_ANY,
- .help = "Enable/Disable non-standard but fast burst mode"
+ .help = "Enable/Disable potentially risky fast burst mode"
" (default: enabled)",
},
{
diff --git a/src/target/arm11_dbgtap.c b/src/target/arm11_dbgtap.c
index 9ad56622..554d6e2b 100644
--- a/src/target/arm11_dbgtap.c
+++ b/src/target/arm11_dbgtap.c
@@ -230,22 +230,23 @@ int arm11_add_debug_SCAN_N(struct arm11_common *arm11,
return jtag_execute_queue();
}
-/** Write an instruction into the ITR register
+/**
+ * Queue a DR scan of the ITR register. Caller must have selected
+ * scan chain 4 (ITR), possibly using ITRSEL.
*
* \param arm11 Target state variable.
* \param inst An ARM11 processor instruction/opcode.
- * \param flag Optional parameter to retrieve the InstCompl flag
- * (this will be written when the JTAG chain is executed).
- * \param state Pass the final TAP state or ARM11_TAP_DEFAULT for the default
- * value (Run-Test/Idle).
+ * \param flag Optional parameter to retrieve the Ready flag;
+ * this address will be written when the JTAG chain is scanned.
+ * \param state The TAP state to enter after the DR scan.
*
- * \remarks By default this ends with Run-Test/Idle state
- * and causes the instruction to be executed. If
- * a subsequent write to DTR is needed before
- * executing the instruction then TAP_DRPAUSE should be
- * passed to \p state.
+ * Going through the TAP_DRUPDATE state writes ITR only if Ready was
+ * previously set. Only the Ready flag is readable by the scan.
*
- * \remarks This adds to the JTAG command queue but does \em not execute it.
+ * An instruction loaded into ITR is executed when going through the
+ * TAP_IDLE state only if Ready was previously set and the debug state
+ * is properly set up. Depending on the instruction, you may also need
+ * to ensure that the rDTR is ready before that Run-Test/Idle state.
*/
static void arm11_add_debug_INST(struct arm11_common * arm11,
uint32_t inst, uint8_t * flag, tap_state_t state)
@@ -257,7 +258,7 @@ static void arm11_add_debug_INST(struct arm11_common * arm11,
arm11_setup_field(arm11, 32, &inst, NULL, itr + 0);
arm11_setup_field(arm11, 1, NULL, flag, itr + 1);
- arm11_add_dr_scan_vc(ARRAY_SIZE(itr), itr, state == ARM11_TAP_DEFAULT ? TAP_IDLE : state);
+ arm11_add_dr_scan_vc(ARRAY_SIZE(itr), itr, state);
}
/**
@@ -374,7 +375,11 @@ int arm11_run_instr_data_finish(struct arm11_common * arm11)
-/** Execute one or multiple instructions via ITR
+/**
+ * Execute one or more instructions via ITR.
+ * Caller guarantees that processor is in debug state, that DSCR_ITR_EN
+ * is set, the ITR Ready flag is set (as seen on the previous entry to
+ * TAP_DRCAPTURE), and the DSCR sticky abort flag is clear.
*
* \pre arm11_run_instr_data_prepare() / arm11_run_instr_data_finish() block
*
@@ -444,6 +449,10 @@ int arm11_run_instr_no_data1(struct arm11_common * arm11, uint32_t opcode)
/** Execute one instruction via ITR repeatedly while
* passing data to the core via DTR on each execution.
*
+ * Caller guarantees that processor is in debug state, that DSCR_ITR_EN
+ * is set, the ITR Ready flag is set (as seen on the previous entry to
+ * TAP_DRCAPTURE), and the DSCR sticky abort flag is clear.
+ *
* The executed instruction \em must read data from DTR.
*
* \pre arm11_run_instr_data_prepare() / arm11_run_instr_data_finish() block
@@ -570,6 +579,10 @@ static const tap_state_t arm11_MOVE_DRPAUSE_IDLE_DRPAUSE_with_delay[] =
/** Execute one instruction via ITR repeatedly while
* passing data to the core via DTR on each execution.
*
+ * Caller guarantees that processor is in debug state, that DSCR_ITR_EN
+ * is set, the ITR Ready flag is set (as seen on the previous entry to
+ * TAP_DRCAPTURE), and the DSCR sticky abort flag is clear.
+ *
* No Ready check during transmission.
*
* The executed instruction \em must read data from DTR.
@@ -678,6 +691,10 @@ int arm11_run_instr_data_to_core1(struct arm11_common * arm11, uint32_t opcode,
/** Execute one instruction via ITR repeatedly while
* reading data from the core via DTR on each execution.
*
+ * Caller guarantees that processor is in debug state, that DSCR_ITR_EN
+ * is set, the ITR Ready flag is set (as seen on the previous entry to
+ * TAP_DRCAPTURE), and the DSCR sticky abort flag is clear.
+ *
* The executed instruction \em must write data to DTR.
*
* \pre arm11_run_instr_data_prepare() / arm11_run_instr_data_finish() block