cortex_a : optimize apb read/write access.
[openocd.git] / src / target / cortex_a.c
old mode 100755 (executable)
new mode 100644 (file)
index e1c4c9c..cc1552d
@@ -67,6 +67,8 @@ static int cortex_a8_dap_write_coreregister_u32(struct target *target,
 static int cortex_a8_mmu(struct target *target, int *enabled);
 static int cortex_a8_virt2phys(struct target *target,
        uint32_t virt, uint32_t *phys);
+static int cortex_a8_read_apb_ab_memory(struct target *target,
+       uint32_t address, uint32_t size, uint32_t count, uint8_t *buffer);
 
 /*
  * FIXME do topology discovery using the ROM; don't
@@ -812,6 +814,7 @@ static int cortex_a8_poll(struct target *target)
                        LOG_DEBUG("Target halted");
                        target->state = TARGET_HALTED;
                        if ((prev_target_state == TARGET_RUNNING)
+                               || (prev_target_state == TARGET_UNKNOWN)
                                || (prev_target_state == TARGET_RESET)) {
                                retval = cortex_a8_debug_entry(target);
                                if (retval != ERROR_OK)
@@ -1397,13 +1400,13 @@ static int cortex_a8_set_breakpoint(struct target *target,
                        buf_set_u32(code, 0, 32, ARMV5_T_BKPT(0x11));
                else
                        buf_set_u32(code, 0, 32, ARMV5_BKPT(0x11));
-               retval = target->type->read_memory(target,
+               retval = target_read_memory(target,
                                breakpoint->address & 0xFFFFFFFE,
                                breakpoint->length, 1,
                                breakpoint->orig_instr);
                if (retval != ERROR_OK)
                        return retval;
-               retval = target->type->write_memory(target,
+               retval = target_write_memory(target,
                                breakpoint->address & 0xFFFFFFFE,
                                breakpoint->length, 1, code);
                if (retval != ERROR_OK)
@@ -1629,13 +1632,13 @@ static int cortex_a8_unset_breakpoint(struct target *target, struct breakpoint *
        } else {
                /* restore original instruction (kept in target endianness) */
                if (breakpoint->length == 4) {
-                       retval = target->type->write_memory(target,
+                       retval = target_write_memory(target,
                                        breakpoint->address & 0xFFFFFFFE,
                                        4, 1, breakpoint->orig_instr);
                        if (retval != ERROR_OK)
                                return retval;
                } else {
-                       retval = target->type->write_memory(target,
+                       retval = target_write_memory(target,
                                        breakpoint->address & 0xFFFFFFFE,
                                        2, 1, breakpoint->orig_instr);
                        if (retval != ERROR_OK)
@@ -1786,127 +1789,302 @@ static int cortex_a8_write_apb_ab_memory(struct target *target,
        int retval = ERROR_COMMAND_SYNTAX_ERROR;
        struct armv7a_common *armv7a = target_to_armv7a(target);
        struct arm *arm = &armv7a->arm;
+       struct adiv5_dap *swjdp = armv7a->arm.dap;
        int total_bytes = count * size;
-       int start_byte, nbytes_to_write, i;
+       int total_u32;
+       int start_byte = address & 0x3;
+       int end_byte   = (address + total_bytes) & 0x3;
        struct reg *reg;
-       union _data {
-               uint8_t uc_a[4];
-               uint32_t ui;
-       } data;
+       uint32_t dscr;
+       uint8_t *tmp_buff = NULL;
 
        if (target->state != TARGET_HALTED) {
                LOG_WARNING("target not halted");
                return ERROR_TARGET_NOT_HALTED;
        }
 
+       total_u32 = DIV_ROUND_UP((address & 3) + total_bytes, 4);
+
+       /* Mark register R0 as dirty, as it will be used
+        * for transferring the data.
+        * It will be restored automatically when exiting
+        * debug mode
+        */
        reg = arm_reg_current(arm, 0);
-       reg->dirty = 1;
-       reg = arm_reg_current(arm, 1);
-       reg->dirty = 1;
+       reg->dirty = true;
 
-       retval = cortex_a8_dap_write_coreregister_u32(target, address & 0xFFFFFFFC, 0);
+       /*  clear any abort  */
+       retval = mem_ap_sel_write_atomic_u32(swjdp, armv7a->debug_ap, armv7a->debug_base + CPUDBG_DRCR, 1<<2);
        if (retval != ERROR_OK)
                return retval;
 
-       start_byte = address & 0x3;
+       /* This algorithm comes from either :
+        * Cortex-A8 TRM Example 12-25
+        * Cortex-R4 TRM Example 11-26
+        * (slight differences)
+        */
 
-       while (total_bytes > 0) {
+       /* The algorithm only copies 32 bit words, so the buffer
+        * should be expanded to include the words at either end.
+        * The first and last words will be read first to avoid
+        * corruption if needed.
+        */
+       tmp_buff = (uint8_t *) malloc(total_u32 << 2);
 
-               nbytes_to_write = 4 - start_byte;
-               if (total_bytes < nbytes_to_write)
-                       nbytes_to_write = total_bytes;
 
-               if (nbytes_to_write != 4) {
+       if ((start_byte != 0) && (total_u32 > 1)) {
+               /* First bytes not aligned - read the 32 bit word to avoid corrupting
+                * the other bytes in the word.
+                */
+               retval = cortex_a8_read_apb_ab_memory(target, (address & ~0x3), 4, 1, tmp_buff);
+               if (retval != ERROR_OK)
+                       goto error_free_buff_w;
+       }
 
-                       /* execute instruction LDR r1, [r0] */
-                       retval = cortex_a8_exec_opcode(target,  ARMV4_5_LDR(1, 0), NULL);
-                       if (retval != ERROR_OK)
-                               return retval;
+       /* If end of write is not aligned, or the write is less than 4 bytes */
+       if ((end_byte != 0) ||
+               ((total_u32 == 1) && (total_bytes != 4))) {
 
-                       retval = cortex_a8_dap_read_coreregister_u32(target, &data.ui, 1);
-                       if (retval != ERROR_OK)
-                               return retval;
-               }
+               /* Read the last word to avoid corruption during 32 bit write */
+               int mem_offset = (total_u32-1) << 4;
+               retval = cortex_a8_read_apb_ab_memory(target, (address & ~0x3) + mem_offset, 4, 1, &tmp_buff[mem_offset]);
+               if (retval != ERROR_OK)
+                       goto error_free_buff_w;
+       }
 
-               for (i = 0; i < nbytes_to_write; ++i)
-                       data.uc_a[i + start_byte] = *buffer++;
+       /* Copy the write buffer over the top of the temporary buffer */
+       memcpy(&tmp_buff[start_byte], buffer, total_bytes);
 
-               retval = cortex_a8_dap_write_coreregister_u32(target, data.ui, 1);
-               if (retval != ERROR_OK)
-                       return retval;
+       /* We now have a 32 bit aligned buffer that can be written */
 
-               /* execute instruction STRW r1, [r0], 1 (0xe4801004) */
-               retval = cortex_a8_exec_opcode(target, ARMV4_5_STRW_IP(1, 0), NULL);
-               if (retval != ERROR_OK)
-                       return retval;
+       /* Read DSCR */
+       retval = mem_ap_sel_read_atomic_u32(swjdp, armv7a->debug_ap,
+                       armv7a->debug_base + CPUDBG_DSCR, &dscr);
+       if (retval != ERROR_OK)
+               goto error_free_buff_w;
+
+       /* Set DTR mode to Fast (2) */
+       dscr = (dscr & ~DSCR_EXT_DCC_MASK) | DSCR_EXT_DCC_FAST_MODE;
+       retval = mem_ap_sel_write_atomic_u32(swjdp, armv7a->debug_ap,
+                       armv7a->debug_base + CPUDBG_DSCR, dscr);
+       if (retval != ERROR_OK)
+               goto error_free_buff_w;
+
+       /* Copy the destination address into R0 */
+       /*  - pend an instruction  MRC p14, 0, R0, c5, c0 */
+       retval = mem_ap_sel_write_atomic_u32(swjdp, armv7a->debug_ap,
+                               armv7a->debug_base + CPUDBG_ITR, ARMV4_5_MRC(14, 0, 0, 0, 5, 0));
+       if (retval != ERROR_OK)
+               goto error_unset_dtr_w;
+       /* Write address into DTRRX, which triggers previous instruction */
+       retval = mem_ap_sel_write_atomic_u32(swjdp, armv7a->debug_ap,
+                               armv7a->debug_base + CPUDBG_DTRRX, address & (~0x3));
+       if (retval != ERROR_OK)
+               goto error_unset_dtr_w;
+
+       /* Write the data transfer instruction into the ITR
+        * (STC p14, c5, [R0], 4)
+        */
+       retval = mem_ap_sel_write_atomic_u32(swjdp, armv7a->debug_ap,
+                               armv7a->debug_base + CPUDBG_ITR, ARMV4_5_STC(0, 1, 0, 1, 14, 5, 0, 4));
+       if (retval != ERROR_OK)
+               goto error_unset_dtr_w;
+
+       /* Do the write */
+       retval = mem_ap_sel_write_buf_u32_noincr(swjdp, armv7a->debug_ap,
+                                       tmp_buff, (total_u32)<<2, armv7a->debug_base + CPUDBG_DTRRX);
+       if (retval != ERROR_OK)
+               goto error_unset_dtr_w;
+
+
+       /* Switch DTR mode back to non-blocking (0) */
+       dscr = (dscr & ~DSCR_EXT_DCC_MASK) | DSCR_EXT_DCC_NON_BLOCKING;
+       retval = mem_ap_sel_write_atomic_u32(swjdp, armv7a->debug_ap,
+                               armv7a->debug_base + CPUDBG_DSCR, dscr);
+       if (retval != ERROR_OK)
+               goto error_unset_dtr_w;
 
-               total_bytes -= nbytes_to_write;
-               start_byte = 0;
+    /* Check for sticky abort flags in the DSCR */
+       retval = mem_ap_sel_read_atomic_u32(swjdp, armv7a->debug_ap,
+                               armv7a->debug_base + CPUDBG_DSCR, &dscr);
+       if (retval != ERROR_OK)
+               goto error_free_buff_w;
+       if (dscr & (DSCR_STICKY_ABORT_PRECISE | DSCR_STICKY_ABORT_IMPRECISE)) {
+               /* Abort occurred - clear it and exit */
+               LOG_ERROR("abort occurred - dscr = 0x%08x", dscr);
+               mem_ap_sel_write_atomic_u32(swjdp, armv7a->debug_ap,
+                                       armv7a->debug_base + CPUDBG_DRCR, 1<<2);
+               goto error_free_buff_w;
        }
 
-       return retval;
-}
+       /* Done */
+       free(tmp_buff);
+       return ERROR_OK;
 
+error_unset_dtr_w:
+       /* Unset DTR mode */
+       mem_ap_sel_read_atomic_u32(swjdp, armv7a->debug_ap,
+                               armv7a->debug_base + CPUDBG_DSCR, &dscr);
+       dscr = (dscr & ~DSCR_EXT_DCC_MASK) | DSCR_EXT_DCC_NON_BLOCKING;
+       mem_ap_sel_write_atomic_u32(swjdp, armv7a->debug_ap,
+                               armv7a->debug_base + CPUDBG_DSCR, dscr);
+error_free_buff_w:
+       LOG_ERROR("error");
+       free(tmp_buff);
+       return ERROR_FAIL;
+}
 
 static int cortex_a8_read_apb_ab_memory(struct target *target,
        uint32_t address, uint32_t size,
        uint32_t count, uint8_t *buffer)
 {
-
        /* read memory through APB-AP */
 
        int retval = ERROR_COMMAND_SYNTAX_ERROR;
        struct armv7a_common *armv7a = target_to_armv7a(target);
+       struct adiv5_dap *swjdp = armv7a->arm.dap;
        struct arm *arm = &armv7a->arm;
        int total_bytes = count * size;
-       int start_byte, nbytes_to_read, i;
+       int total_u32;
+       int start_byte = address & 0x3;
        struct reg *reg;
-       union _data {
-               uint8_t uc_a[4];
-               uint32_t ui;
-       } data;
-
+       uint32_t dscr;
+       char *tmp_buff = NULL;
+       uint32_t buff32[2];
        if (target->state != TARGET_HALTED) {
                LOG_WARNING("target not halted");
                return ERROR_TARGET_NOT_HALTED;
        }
 
+       total_u32 = DIV_ROUND_UP((address & 3) + total_bytes, 4);
+
+       /* Mark register R0 as dirty, as it will be used
+        * for transferring the data.
+        * It will be restored automatically when exiting
+        * debug mode
+        */
        reg = arm_reg_current(arm, 0);
-       reg->dirty = 1;
-       reg = arm_reg_current(arm, 1);
-       reg->dirty = 1;
+       reg->dirty = true;
 
-       retval = cortex_a8_dap_write_coreregister_u32(target, address & 0xFFFFFFFC, 0);
+       /*  clear any abort  */
+       retval =
+               mem_ap_sel_write_atomic_u32(swjdp, armv7a->debug_ap, armv7a->debug_base + CPUDBG_DRCR, 1<<2);
        if (retval != ERROR_OK)
                return retval;
 
-       start_byte = address & 0x3;
+       /* Read DSCR */
+       retval = mem_ap_sel_read_atomic_u32(swjdp, armv7a->debug_ap,
+                       armv7a->debug_base + CPUDBG_DSCR, &dscr);
 
-       while (total_bytes > 0) {
+       /* This algorithm comes from either :
+        * Cortex-A8 TRM Example 12-24
+        * Cortex-R4 TRM Example 11-25
+        * (slight differences)
+        */
+
+       /* Set DTR access mode to stall mode b01  */
+       dscr = (dscr & ~DSCR_EXT_DCC_MASK) | DSCR_EXT_DCC_STALL_MODE;
+       retval +=  mem_ap_sel_write_atomic_u32(swjdp, armv7a->debug_ap,
+                       armv7a->debug_base + CPUDBG_DSCR, dscr);
+
+    /* Write R0 with value 'address' using write procedure for stall mode */
+       /*   - Write the address for read access into DTRRX */
+       retval += mem_ap_sel_write_atomic_u32(swjdp, armv7a->debug_ap,
+                       armv7a->debug_base + CPUDBG_DTRRX, address & ~0x3);
+       /*  - Copy value from DTRRX to R0 using instruction mrc p14, 0, r0, c5, c0 */
+       cortex_a8_exec_opcode(target, ARMV4_5_MRC(14, 0, 0, 0, 5, 0), &dscr);
+
+
+       /* Write the data transfer instruction (ldc p14, c5, [r0],4)
+        * and the DTR mode setting to fast mode
+        * in one combined write (since they are adjacent registers)
+        */
+       buff32[0] = ARMV4_5_LDC(0, 1, 0, 1, 14, 5, 0, 4);
+       dscr = (dscr & ~DSCR_EXT_DCC_MASK) | DSCR_EXT_DCC_FAST_MODE;
+       buff32[1] = dscr;
+       /*  group the 2 access CPUDBG_ITR 0x84 and CPUDBG_DSCR 0x88 */
+       retval += mem_ap_sel_write_buf_u32(swjdp, armv7a->debug_ap, (uint8_t *)buff32, 8,
+                       armv7a->debug_base + CPUDBG_ITR);
+       if (retval != ERROR_OK)
+               goto error_unset_dtr_r;
+
+
+       /* Due to offset word alignment, the  buffer may not have space
+        * to read the full first and last int32 words,
+        * hence, malloc space to read into, then copy and align into the buffer.
+        */
+       tmp_buff = (char *) malloc(total_u32<<2);
 
-               /* execute instruction LDRW r1, [r0], 4 (0xe4901004)  */
-               retval = cortex_a8_exec_opcode(target,  ARMV4_5_LDRW_IP(1, 0), NULL);
+       /* The last word needs to be handled separately - read all other words in one go.
+        */
+       if (total_u32 > 1) {
+               /* Read the data - Each read of the DTRTX register causes the instruction to be reissued
+                * Abort flags are sticky, so can be read at end of transactions
+                *
+                * This data is read in aligned to 32 bit boundary, hence may need shifting later.
+                */
+               retval = mem_ap_sel_read_buf_u32_noincr(swjdp, armv7a->debug_ap, (uint8_t *)tmp_buff, (total_u32-1)<<2,
+                                                                       armv7a->debug_base + CPUDBG_DTRTX);
                if (retval != ERROR_OK)
-                       return retval;
+                       goto error_unset_dtr_r;
+       }
 
-               retval = cortex_a8_dap_read_coreregister_u32(target, &data.ui, 1);
+       /* set DTR access mode back to non blocking b00  */
+       dscr = (dscr & ~DSCR_EXT_DCC_MASK) | DSCR_EXT_DCC_NON_BLOCKING;
+       retval =  mem_ap_sel_write_atomic_u32(swjdp, armv7a->debug_ap,
+                                       armv7a->debug_base + CPUDBG_DSCR, dscr);
+       if (retval != ERROR_OK)
+               goto error_free_buff_r;
+
+       /* Wait for the final read instruction to finish */
+       do {
+               retval = mem_ap_sel_read_atomic_u32(swjdp, armv7a->debug_ap,
+                                       armv7a->debug_base + CPUDBG_DSCR, &dscr);
                if (retval != ERROR_OK)
-                       return retval;
+                       goto error_free_buff_r;
+       } while ((dscr & DSCR_INSTR_COMP) == 0);
+
 
-               nbytes_to_read = 4 - start_byte;
-               if (total_bytes < nbytes_to_read)
-                       nbytes_to_read = total_bytes;
+       /* Check for sticky abort flags in the DSCR */
+       retval = mem_ap_sel_read_atomic_u32(swjdp, armv7a->debug_ap,
+                               armv7a->debug_base + CPUDBG_DSCR, &dscr);
+       if (retval != ERROR_OK)
+               goto error_free_buff_r;
+       if (dscr & (DSCR_STICKY_ABORT_PRECISE | DSCR_STICKY_ABORT_IMPRECISE)) {
+               /* Abort occurred - clear it and exit */
+               LOG_ERROR("abort occurred - dscr = 0x%08x", dscr);
+               mem_ap_sel_write_atomic_u32(swjdp, armv7a->debug_ap,
+                                       armv7a->debug_base + CPUDBG_DRCR, 1<<2);
+               goto error_free_buff_r;
+       }
+
+       /* Read the last word */
+       retval = mem_ap_sel_read_atomic_u32(swjdp, armv7a->debug_ap,
+                               armv7a->debug_base + CPUDBG_DTRTX, (uint32_t *)&tmp_buff[(total_u32-1)<<2]);
+       if (retval != ERROR_OK)
+               goto error_free_buff_r;
 
-               for (i = 0; i < nbytes_to_read; ++i)
-                       *buffer++ = data.uc_a[i + start_byte];
+       /* Copy and align the data into the output buffer */
+       memcpy(buffer, &tmp_buff[start_byte], total_bytes);
 
-               total_bytes -= nbytes_to_read;
-               start_byte = 0;
-       }
+       free(tmp_buff);
+
+       /* Done */
+       return ERROR_OK;
 
-       return retval;
-}
 
+error_unset_dtr_r:
+       /* Unset DTR mode */
+       mem_ap_sel_read_atomic_u32(swjdp, armv7a->debug_ap,
+                               armv7a->debug_base + CPUDBG_DSCR, &dscr);
+       dscr = (dscr & ~DSCR_EXT_DCC_MASK) | DSCR_EXT_DCC_NON_BLOCKING;
+       mem_ap_sel_write_atomic_u32(swjdp, armv7a->debug_ap,
+                               armv7a->debug_base + CPUDBG_DSCR, dscr);
+error_free_buff_r:
+       LOG_ERROR("error");
+       free(tmp_buff);
+       return ERROR_FAIL;
+}
 
 
 /*

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