* clean the trace buffer if it is to be enabled (0x62) */
if (xscale->trace.buffer_enabled)
{
- /* if trace buffer is set to 'fill' mode, save starting pc */
- if (xscale->trace.buffer_fill > 0)
- {
- xscale->trace.pc_ok = 1;
- xscale->trace.current_pc = buf_get_u32(armv4_5->pc->value, 0, 32);
- }
xscale_send_u32(target, 0x62);
xscale_send_u32(target, 0x31);
}
uint32_t trace_buffer[258];
int is_address[256];
int i, j;
+ unsigned int num_checkpoints = 0;
if (target->state != TARGET_HALTED)
{
/* parse buffer backwards to identify address entries */
for (i = 255; i >= 0; i--)
{
+ /* also count number of checkpointed entries */
+ if ((trace_buffer[i] & 0xe0) == 0xc0)
+ num_checkpoints++;
+
is_address[i] = 0;
if (((trace_buffer[i] & 0xf0) == 0x90) ||
((trace_buffer[i] & 0xf0) == 0xd0))
{
- if (i >= 3)
+ if (i > 0)
is_address[--i] = 1;
- if (i >= 2)
+ if (i > 0)
is_address[--i] = 1;
- if (i >= 1)
+ if (i > 0)
is_address[--i] = 1;
- if (i >= 0)
+ if (i > 0)
is_address[--i] = 1;
}
}
- /* search first non-zero entry */
+ /* search first non-zero entry that is not part of an address */
for (j = 0; (j < 256) && (trace_buffer[j] == 0) && (!is_address[j]); j++)
;
return ERROR_XSCALE_NO_TRACE_DATA;
}
+ /* account for possible partial address at buffer start (wrap mode only) */
+ if (is_address[0])
+ { /* first entry is address; complete set of 4? */
+ i = 1;
+ while (i < 4)
+ if (!is_address[i++])
+ break;
+ if (i < 4)
+ j += i; /* partial address; can't use it */
+ }
+
+ /* if first valid entry is indirect branch, can't use that either (no address) */
+ if (((trace_buffer[j] & 0xf0) == 0x90) || ((trace_buffer[j] & 0xf0) == 0xd0))
+ j++;
+
+ /* walk linked list to terminating entry */
for (trace_data_p = &xscale->trace.data; *trace_data_p; trace_data_p = &(*trace_data_p)->next)
;
buf_get_u32(armv4_5->pc->value, 0, 32);
(*trace_data_p)->entries = malloc(sizeof(struct xscale_trace_entry) * (256 - j));
(*trace_data_p)->depth = 256 - j;
+ (*trace_data_p)->num_checkpoints = num_checkpoints;
for (i = j; i < 256; i++)
{
return ERROR_OK;
}
-static int xscale_read_instruction(struct target *target,
- struct arm_instruction *instruction)
+static int xscale_read_instruction(struct target *target, uint32_t pc,
+ struct arm_instruction *instruction)
{
- struct xscale_common *xscale = target_to_xscale(target);
+ struct xscale_common *const xscale = target_to_xscale(target);
int i;
int section = -1;
size_t size_read;
/* search for the section the current instruction belongs to */
for (i = 0; i < xscale->trace.image->num_sections; i++)
{
- if ((xscale->trace.image->sections[i].base_address <= xscale->trace.current_pc) &&
- (xscale->trace.image->sections[i].base_address + xscale->trace.image->sections[i].size > xscale->trace.current_pc))
+ if ((xscale->trace.image->sections[i].base_address <= pc) &&
+ (xscale->trace.image->sections[i].base_address + xscale->trace.image->sections[i].size > pc))
{
section = i;
break;
{
uint8_t buf[4];
if ((retval = image_read_section(xscale->trace.image, section,
- xscale->trace.current_pc - xscale->trace.image->sections[section].base_address,
+ pc - xscale->trace.image->sections[section].base_address,
4, buf, &size_read)) != ERROR_OK)
{
LOG_ERROR("error while reading instruction: %i", retval);
return ERROR_TRACE_INSTRUCTION_UNAVAILABLE;
}
opcode = target_buffer_get_u32(target, buf);
- arm_evaluate_opcode(opcode, xscale->trace.current_pc, instruction);
+ arm_evaluate_opcode(opcode, pc, instruction);
}
else if (xscale->trace.core_state == ARM_STATE_THUMB)
{
uint8_t buf[2];
if ((retval = image_read_section(xscale->trace.image, section,
- xscale->trace.current_pc - xscale->trace.image->sections[section].base_address,
+ pc - xscale->trace.image->sections[section].base_address,
2, buf, &size_read)) != ERROR_OK)
{
LOG_ERROR("error while reading instruction: %i", retval);
return ERROR_TRACE_INSTRUCTION_UNAVAILABLE;
}
opcode = target_buffer_get_u16(target, buf);
- thumb_evaluate_opcode(opcode, xscale->trace.current_pc, instruction);
+ thumb_evaluate_opcode(opcode, pc, instruction);
}
else
{
return ERROR_OK;
}
-static int xscale_branch_address(struct xscale_trace_data *trace_data,
- int i, uint32_t *target)
+/* Extract address encoded into trace data.
+ * Write result to address referenced by argument 'target', or 0 if incomplete. */
+static inline void xscale_branch_address(struct xscale_trace_data *trace_data,
+ int i, uint32_t *target)
{
/* if there are less than four entries prior to the indirect branch message
* we can't extract the address */
if (i < 4)
- {
- return -1;
- }
-
- *target = (trace_data->entries[i-1].data) | (trace_data->entries[i-2].data << 8) |
- (trace_data->entries[i-3].data << 16) | (trace_data->entries[i-4].data << 24);
+ *target = 0;
+ else
+ *target = (trace_data->entries[i-1].data) | (trace_data->entries[i-2].data << 8) |
+ (trace_data->entries[i-3].data << 16) | (trace_data->entries[i-4].data << 24);
+}
- return 0;
+static inline void xscale_display_instruction(struct target *target, uint32_t pc,
+ struct arm_instruction *instruction,
+ struct command_context *cmd_ctx)
+{
+ int retval = xscale_read_instruction(target, pc, instruction);
+ if (retval == ERROR_OK)
+ command_print(cmd_ctx, "%s", instruction->text);
+ else
+ command_print(cmd_ctx, "0x%8.8" PRIx32 "\t<not found in image>", pc);
}
static int xscale_analyze_trace(struct target *target, struct command_context *cmd_ctx)
{
- struct xscale_common *xscale = target_to_xscale(target);
- int next_pc_ok = 0;
- uint32_t next_pc = 0x0;
- struct xscale_trace_data *trace_data = xscale->trace.data;
- int retval;
-
- while (trace_data)
- {
- int i, chkpt;
- int rollover;
- int branch;
- int exception;
- xscale->trace.core_state = ARM_STATE_ARM;
-
- chkpt = 0;
- rollover = 0;
+ struct xscale_common *xscale = target_to_xscale(target);
+ struct xscale_trace_data *trace_data = xscale->trace.data;
+ int i, retval;
+ uint32_t breakpoint_pc;
+ struct arm_instruction instruction;
+ uint32_t current_pc = 0; /* initialized when address determined */
+
+ if (!xscale->trace.image)
+ LOG_WARNING("No trace image loaded; use 'xscale trace_image'");
+
+ /* loop for each trace buffer that was loaded from target */
+ while (trace_data)
+ {
+ int chkpt = 0; /* incremented as checkpointed entries found */
+ int j;
+
+ /* FIXME: set this to correct mode when trace buffer is first enabled */
+ xscale->trace.core_state = ARM_STATE_ARM;
+
+ /* loop for each entry in this trace buffer */
+ for (i = 0; i < trace_data->depth; i++)
+ {
+ int exception = 0;
+ uint32_t chkpt_reg = 0x0;
+ uint32_t branch_target = 0;
+ int count;
+
+ /* trace entry type is upper nybble of 'message byte' */
+ int trace_msg_type = (trace_data->entries[i].data & 0xf0) >> 4;
+
+ /* Target addresses of indirect branches are written into buffer
+ * before the message byte representing the branch. Skip past it */
+ if (trace_data->entries[i].type == XSCALE_TRACE_ADDRESS)
+ continue;
- for (i = 0; i < trace_data->depth; i++)
- {
- next_pc_ok = 0;
- branch = 0;
- exception = 0;
+ switch (trace_msg_type)
+ {
+ case 0: /* Exceptions */
+ case 1:
+ case 2:
+ case 3:
+ case 4:
+ case 5:
+ case 6:
+ case 7:
+ exception = (trace_data->entries[i].data & 0x70) >> 4;
+
+ /* FIXME: vector table may be at ffff0000 */
+ branch_target = (trace_data->entries[i].data & 0xf0) >> 2;
+ break;
+
+ case 8: /* Direct Branch */
+ break;
+
+ case 9: /* Indirect Branch */
+ xscale_branch_address(trace_data, i, &branch_target);
+ break;
+
+ case 13: /* Checkpointed Indirect Branch */
+ xscale_branch_address(trace_data, i, &branch_target);
+ if ((trace_data->num_checkpoints == 2) && (chkpt == 0))
+ chkpt_reg = trace_data->chkpt1; /* 2 chkpts, this is oldest */
+ else
+ chkpt_reg = trace_data->chkpt0; /* 1 chkpt, or 2 and newest */
+
+ chkpt++;
+ break;
+
+ case 12: /* Checkpointed Direct Branch */
+ if ((trace_data->num_checkpoints == 2) && (chkpt == 0))
+ chkpt_reg = trace_data->chkpt1; /* 2 chkpts, this is oldest */
+ else
+ chkpt_reg = trace_data->chkpt0; /* 1 chkpt, or 2 and newest */
+
+ /* if no current_pc, checkpoint will be starting point */
+ if (current_pc == 0)
+ branch_target = chkpt_reg;
+
+ chkpt++;
+ break;
+
+ case 15: /* Roll-over */
+ break;
+
+ default: /* Reserved */
+ LOG_WARNING("trace is suspect: invalid trace message byte");
+ continue;
+
+ }
+
+ /* If we don't have the current_pc yet, but we did get the branch target
+ * (either from the trace buffer on indirect branch, or from a checkpoint reg),
+ * then we can start displaying instructions at the next iteration, with
+ * branch_target as the starting point.
+ */
+ if (current_pc == 0)
+ {
+ current_pc = branch_target; /* remains 0 unless branch_target obtained */
+ continue;
+ }
+
+ /* We have current_pc. Read and display the instructions from the image.
+ * First, display count instructions (lower nybble of message byte). */
+ count = trace_data->entries[i].data & 0x0f;
+ for (j = 0; j < count; j++)
+ {
+ xscale_display_instruction(target, current_pc, &instruction, cmd_ctx);
+ current_pc += xscale->trace.core_state == ARM_STATE_ARM ? 4 : 2;
+ }
+
+ /* An additional instruction is implicitly added to count for
+ * rollover and some exceptions: undef, swi, prefetch abort. */
+ if ((trace_msg_type == 15) || (exception > 0 && exception < 4))
+ {
+ xscale_display_instruction(target, current_pc, &instruction, cmd_ctx);
+ current_pc += xscale->trace.core_state == ARM_STATE_ARM ? 4 : 2;
+ }
+
+ if (trace_msg_type == 15) /* rollover */
+ continue;
- if (trace_data->entries[i].type == XSCALE_TRACE_ADDRESS)
- continue;
+ if (exception)
+ {
+ command_print(cmd_ctx, "--- exception %i ---", exception);
+ continue;
+ }
+
+ /* not exception or rollover; next instruction is a branch and is
+ * not included in the count */
+ xscale_display_instruction(target, current_pc, &instruction, cmd_ctx);
+
+ /* for direct branches, extract branch destination from instruction */
+ if ((trace_msg_type == 8) || (trace_msg_type == 12))
+ {
+ retval = xscale_read_instruction(target, current_pc, &instruction);
+ if (retval == ERROR_OK)
+ current_pc = instruction.info.b_bl_bx_blx.target_address;
+ else
+ current_pc = 0; /* branch destination unknown */
- switch ((trace_data->entries[i].data & 0xf0) >> 4)
+ /* direct branch w/ checkpoint; can also get from checkpoint reg */
+ if (trace_msg_type == 12)
{
- case 0: /* Exceptions */
- case 1:
- case 2:
- case 3:
- case 4:
- case 5:
- case 6:
- case 7:
- exception = (trace_data->entries[i].data & 0x70) >> 4;
- next_pc_ok = 1;
- next_pc = (trace_data->entries[i].data & 0xf0) >> 2;
- command_print(cmd_ctx, "--- exception %i ---", (trace_data->entries[i].data & 0xf0) >> 4);
- break;
- case 8: /* Direct Branch */
- branch = 1;
- break;
- case 9: /* Indirect Branch */
- branch = 1;
- if (xscale_branch_address(trace_data, i, &next_pc) == 0)
- {
- next_pc_ok = 1;
- }
- break;
- case 13: /* Checkpointed Indirect Branch */
- if (xscale_branch_address(trace_data, i, &next_pc) == 0)
- {
- next_pc_ok = 1;
- if (((chkpt == 0) && (next_pc != trace_data->chkpt0))
- || ((chkpt == 1) && (next_pc != trace_data->chkpt1)))
- LOG_WARNING("checkpointed indirect branch target address doesn't match checkpoint");
- }
- /* explicit fall-through */
- case 12: /* Checkpointed Direct Branch */
- branch = 1;
- if (chkpt == 0)
- {
- next_pc_ok = 1;
- next_pc = trace_data->chkpt0;
- chkpt++;
- }
- else if (chkpt == 1)
- {
- next_pc_ok = 1;
- next_pc = trace_data->chkpt0;
- chkpt++;
- }
- else
- {
- LOG_WARNING("more than two checkpointed branches encountered");
- }
- break;
- case 15: /* Roll-over */
- rollover++;
- continue;
- default: /* Reserved */
- command_print(cmd_ctx, "--- reserved trace message ---");
- LOG_ERROR("BUG: trace message %i is reserved", (trace_data->entries[i].data & 0xf0) >> 4);
- return ERROR_OK;
+ if (current_pc == 0)
+ current_pc = chkpt_reg;
+ else if (current_pc != chkpt_reg) /* sanity check */
+ LOG_WARNING("trace is suspect: checkpoint register "
+ "inconsistent with adddress from image");
}
- if (xscale->trace.pc_ok)
- {
- int executed = (trace_data->entries[i].data & 0xf) + rollover * 16;
- struct arm_instruction instruction;
+ if (current_pc == 0)
+ command_print(cmd_ctx, "address unknown");
- if ((exception == 6) || (exception == 7))
- {
- /* IRQ or FIQ exception, no instruction executed */
- executed -= 1;
- }
+ continue;
+ }
- while (executed-- >= 0)
- {
- if ((retval = xscale_read_instruction(target, &instruction)) != ERROR_OK)
- {
- /* can't continue tracing with no image available */
- if (retval == ERROR_TRACE_IMAGE_UNAVAILABLE)
- {
- return retval;
- }
- else if (retval == ERROR_TRACE_INSTRUCTION_UNAVAILABLE)
- {
- /* TODO: handle incomplete images */
- }
- }
-
- /* a precise abort on a load to the PC is included in the incremental
- * word count, other instructions causing data aborts are not included
- */
- if ((executed == 0) && (exception == 4)
- && ((instruction.type >= ARM_LDR) && (instruction.type <= ARM_LDM)))
- {
- if ((instruction.type == ARM_LDM)
- && ((instruction.info.load_store_multiple.register_list & 0x8000) == 0))
- {
- executed--;
- }
- else if (((instruction.type >= ARM_LDR) && (instruction.type <= ARM_LDRSH))
- && (instruction.info.load_store.Rd != 15))
- {
- executed--;
- }
- }
-
- /* only the last instruction executed
- * (the one that caused the control flow change)
- * could be a taken branch
- */
- if (((executed == -1) && (branch == 1)) &&
- (((instruction.type == ARM_B) ||
- (instruction.type == ARM_BL) ||
- (instruction.type == ARM_BLX)) &&
- (instruction.info.b_bl_bx_blx.target_address != 0xffffffff)))
- {
- xscale->trace.current_pc = instruction.info.b_bl_bx_blx.target_address;
- }
- else
- {
- xscale->trace.current_pc += (xscale->trace.core_state == ARM_STATE_ARM) ? 4 : 2;
- }
- command_print(cmd_ctx, "%s", instruction.text);
- }
+ /* indirect branch; the branch destination was read from trace buffer */
+ if ((trace_msg_type == 9) || (trace_msg_type == 13))
+ {
+ current_pc = branch_target;
- rollover = 0;
- }
+ /* sanity check (checkpoint reg is redundant) */
+ if ((trace_msg_type == 13) && (chkpt_reg != branch_target))
+ LOG_WARNING("trace is suspect: checkpoint register "
+ "inconsistent with address from trace buffer");
+ }
- if (next_pc_ok)
- {
- xscale->trace.current_pc = next_pc;
- xscale->trace.pc_ok = 1;
- }
- }
+ } /* END: for (i = 0; i < trace_data->depth; i++) */
- for (; xscale->trace.current_pc < trace_data->last_instruction; xscale->trace.current_pc += (xscale->trace.core_state == ARM_STATE_ARM) ? 4 : 2)
- {
- struct arm_instruction instruction;
- if ((retval = xscale_read_instruction(target, &instruction)) != ERROR_OK)
- {
- /* can't continue tracing with no image available */
- if (retval == ERROR_TRACE_IMAGE_UNAVAILABLE)
- {
- return retval;
- }
- else if (retval == ERROR_TRACE_INSTRUCTION_UNAVAILABLE)
- {
- /* TODO: handle incomplete images */
- }
- }
- command_print(cmd_ctx, "%s", instruction.text);
- }
+ breakpoint_pc = trace_data->last_instruction; /* used below */
+ trace_data = trace_data->next;
- trace_data = trace_data->next;
- }
+ } /* END: while (trace_data) */
- return ERROR_OK;
+ /* Finally... display all instructions up to the value of the pc when the
+ * debug break occurred (saved when trace data was collected from target).
+ * This is necessary because the trace only records execution branches and 16
+ * consecutive instructions (rollovers), so last few typically missed.
+ */
+ if (current_pc == 0)
+ return ERROR_OK; /* current_pc was never found */
+
+ /* how many instructions remaining? */
+ int gap_count = (breakpoint_pc - current_pc) /
+ (xscale->trace.core_state == ARM_STATE_ARM ? 4 : 2);
+
+ /* should never be negative or over 16, but verify */
+ if (gap_count < 0 || gap_count > 16)
+ {
+ LOG_WARNING("trace is suspect: excessive gap at end of trace");
+ return ERROR_OK; /* bail; large number or negative value no good */
+ }
+
+ /* display remaining instructions */
+ for (i = 0; i < gap_count; i++)
+ {
+ xscale_display_instruction(target, current_pc, &instruction, cmd_ctx);
+ current_pc += xscale->trace.core_state == ARM_STATE_ARM ? 4 : 2;
+ }
+
+ return ERROR_OK;
}
static const struct reg_arch_type xscale_reg_type = {
{
struct target *target = get_current_target(CMD_CTX);
struct xscale_common *xscale = target_to_xscale(target);
- struct arm *armv4_5 = &xscale->armv4_5_common;
uint32_t dcsr_value;
int retval;
xscale->trace.buffer_fill = -1;
}
- if (xscale->trace.buffer_enabled)
- {
- /* if we enable the trace buffer in fill-once
- * mode we know the address of the first instruction */
- xscale->trace.pc_ok = 1;
- xscale->trace.current_pc =
- buf_get_u32(armv4_5->pc->value, 0, 32);
- }
- else
- {
- /* otherwise the address is unknown, and we have no known good PC */
- xscale->trace.pc_ok = 0;
- }
-
command_print(CMD_CTX, "trace buffer %s (%s)",
(xscale->trace.buffer_enabled) ? "enabled" : "disabled",
(xscale->trace.buffer_fill > 0) ? "fill" : "wrap");
projects / openocd / commitdiff