scan_field_t -> struct scan_field
[fw/openocd] / src / target / arm926ejs.c
index f46760e54e07b16c843b98fb32b765090e6805c7..25c44a0e2888aa9f27962a55de8f58abb984a8ca 100644 (file)
@@ -2,6 +2,9 @@
  *   Copyright (C) 2007 by Dominic Rath                                    *
  *   Dominic.Rath@gmx.de                                                   *
  *                                                                         *
+ *   Copyright (C) 2007,2008,2009 by Ã˜yvind Harboe                         *
+ *   oyvind.harboe@zylin.com                                               *
+ *                                                                         *
  *   This program is free software; you can redistribute it and/or modify  *
  *   it under the terms of the GNU General Public License as published by  *
  *   the Free Software Foundation; either version 2 of the License, or     *
 #endif
 
 #include "arm926ejs.h"
-#include "jtag.h"
-#include "log.h"
-
-#include <stdlib.h>
-#include <string.h>
-
-#if 1
+#include "time_support.h"
+#include "target_type.h"
+
+
+/*
+ * The ARM926 is built around the ARM9EJ-S core, and most JTAG docs
+ * are in the ARM9EJ-S Technical Reference Manual (ARM DDI 0222B) not
+ * the ARM926 manual (ARM DDI 0198E).  The scan chains are:
+ *
+ *   1 ... core debugging
+ *   2 ... EmbeddedICE
+ *   3 ... external boundary scan (SoC-specific, unused here)
+ *   6 ... ETM
+ *   15 ... coprocessor 15
+ */
+
+#if 0
 #define _DEBUG_INSTRUCTION_EXECUTION_
 #endif
 
-/* cli handling */
-int arm926ejs_register_commands(struct command_context_s *cmd_ctx);
-
-int arm926ejs_handle_cp15_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
-int arm926ejs_handle_cp15i_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
-int arm926ejs_handle_virt2phys_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
-int arm926ejs_handle_cache_info_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
-int arm926ejs_handle_md_phys_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
-int arm926ejs_handle_mw_phys_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
-
-int arm926ejs_handle_read_cache_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
-int arm926ejs_handle_read_mmu_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
-
-/* forward declarations */
-int arm926ejs_target_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc, struct target_s *target);
-int arm926ejs_init_target(struct command_context_s *cmd_ctx, struct target_s *target);
-int arm926ejs_quit();
-int arm926ejs_arch_state(struct target_s *target);
-int arm926ejs_read_memory(struct target_s *target, u32 address, u32 size, u32 count, u8 *buffer);
-int arm926ejs_write_memory(struct target_s *target, u32 address, u32 size, u32 count, u8 *buffer);
-int arm926ejs_soft_reset_halt(struct target_s *target);
-static int arm926ejs_virt2phys(struct target_s *target, u32 virtual, u32 *physical);
-static int arm926ejs_mmu(struct target_s *target, int *enabled);
+#define ARM926EJS_CP15_ADDR(opcode_1, opcode_2, CRn, CRm) ((opcode_1 << 11) | (opcode_2 << 8) | (CRn << 4) | (CRm << 0))
 
-target_type_t arm926ejs_target =
+static int arm926ejs_cp15_read(target_t *target, uint32_t op1, uint32_t op2,
+               uint32_t CRn, uint32_t CRm, uint32_t *value)
 {
-       .name = "arm926ejs",
-
-       .poll = arm7_9_poll,
-       .arch_state = arm926ejs_arch_state,
-
-       .target_request_data = arm7_9_target_request_data,
-
-       .halt = arm7_9_halt,
-       .resume = arm7_9_resume,
-       .step = arm7_9_step,
-
-       .assert_reset = arm7_9_assert_reset,
-       .deassert_reset = arm7_9_deassert_reset,
-       .soft_reset_halt = arm926ejs_soft_reset_halt,
-       
-       .get_gdb_reg_list = armv4_5_get_gdb_reg_list,
-
-       .read_memory = arm7_9_read_memory,
-       .write_memory = arm926ejs_write_memory,
-       .bulk_write_memory = arm7_9_bulk_write_memory,
-       .checksum_memory = arm7_9_checksum_memory,
-       
-       .run_algorithm = armv4_5_run_algorithm,
-
-       .add_breakpoint = arm7_9_add_breakpoint,
-       .remove_breakpoint = arm7_9_remove_breakpoint,
-       .add_watchpoint = arm7_9_add_watchpoint,
-       .remove_watchpoint = arm7_9_remove_watchpoint,
-
-       .register_commands = arm926ejs_register_commands,
-       .target_command = arm926ejs_target_command,
-       .init_target = arm926ejs_init_target,
-       .examine = arm9tdmi_examine,
-       .quit = arm926ejs_quit,
-       .virt2phys = arm926ejs_virt2phys,
-       .mmu = arm926ejs_mmu
-};
+       int retval = ERROR_OK;
+       struct arm7_9_common_s *arm7_9 = target_to_arm7_9(target);
+       arm_jtag_t *jtag_info = &arm7_9->jtag_info;
+       uint32_t address = ARM926EJS_CP15_ADDR(op1, op2, CRn, CRm);
+       struct scan_field fields[4];
+       uint8_t address_buf[2];
+       uint8_t nr_w_buf = 0;
+       uint8_t access = 1;
 
+       buf_set_u32(address_buf, 0, 14, address);
 
-int arm926ejs_catch_broken_irscan(u8 *captured, void *priv, scan_field_t *field)
-{
-       /* The ARM926EJ-S' instruction register is 4 bits wide */
-       u8 t = *captured & 0xf;
-       u8 t2 = *field->in_check_value & 0xf;
-       if (t == t2)
-       {
-               return ERROR_OK;
-       }
-       else if ((t == 0x0f) || (t == 0x00))
+       jtag_set_end_state(TAP_IDLE);
+       if ((retval = arm_jtag_scann(jtag_info, 0xf)) != ERROR_OK)
        {
-               LOG_DEBUG("caught ARM926EJ-S invalid Capture-IR result after CP15 access");
-               return ERROR_OK;
+               return retval;
        }
-       return ERROR_JTAG_QUEUE_FAILED;;
-}
-
-#define ARM926EJS_CP15_ADDR(opcode_1, opcode_2, CRn, CRm) ((opcode_1 << 11) | (opcode_2 << 8) | (CRn << 4) | (CRm << 0))
-
-int arm926ejs_cp15_read(target_t *target, u32 op1, u32 op2, u32 CRn, u32 CRm, u32 *value)
-{
-       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;
-       u32 address = ARM926EJS_CP15_ADDR(op1, op2, CRn, CRm);
-       scan_field_t fields[4];
-       u8 address_buf[2];
-       u8 nr_w_buf = 0;
-       u8 access = 1;
-       
-       buf_set_u32(address_buf, 0, 14, address);
-       
-       jtag_add_end_state(TAP_RTI);
-       arm_jtag_scann(jtag_info, 0xf);
        arm_jtag_set_instr(jtag_info, jtag_info->intest_instr, NULL);
 
-       fields[0].device = jtag_info->chain_pos;
+       fields[0].tap = jtag_info->tap;
        fields[0].num_bits = 32;
        fields[0].out_value = NULL;
-       fields[0].out_mask = NULL;
-       fields[0].in_value = NULL;
-       fields[0].in_check_value = NULL;
-       fields[0].in_check_mask = NULL;
-       fields[0].in_handler = NULL;
-       fields[0].in_handler_priv = NULL;
+       fields[0].in_value = (uint8_t *)value;
+
 
-       fields[1].device = jtag_info->chain_pos;
+       fields[1].tap = jtag_info->tap;
        fields[1].num_bits = 1;
        fields[1].out_value = &access;
-       fields[1].out_mask = NULL;
        fields[1].in_value = &access;
-       fields[1].in_check_value = NULL;
-       fields[1].in_check_mask = NULL;
-       fields[1].in_handler = NULL;
-       fields[1].in_handler_priv = NULL;
 
-       fields[2].device = jtag_info->chain_pos;
+       fields[2].tap = jtag_info->tap;
        fields[2].num_bits = 14;
        fields[2].out_value = address_buf;
-       fields[2].out_mask = NULL;
        fields[2].in_value = NULL;
-       fields[2].in_check_value = NULL;
-       fields[2].in_check_mask = NULL;
-       fields[2].in_handler = NULL;
-       fields[2].in_handler_priv = NULL;
 
-       fields[3].device = jtag_info->chain_pos;
+       fields[3].tap = jtag_info->tap;
        fields[3].num_bits = 1;
        fields[3].out_value = &nr_w_buf;
-       fields[3].out_mask = NULL;
        fields[3].in_value = NULL;
-       fields[3].in_check_value = NULL;
-       fields[3].in_check_mask = NULL;
-       fields[3].in_handler = NULL;
-       fields[3].in_handler_priv = NULL;
-       
-       jtag_add_dr_scan(4, fields, -1);
-
-       fields[0].in_handler_priv = value;
-       fields[0].in_handler = arm_jtag_buf_to_u32;
-       
-       /*TODO: add timeout*/
-       do
+
+       jtag_add_dr_scan(4, fields, jtag_get_end_state());
+
+       long long then = timeval_ms();
+
+       for (;;)
        {
                /* rescan with NOP, to wait for the access to complete */
                access = 0;
                nr_w_buf = 0;
-               jtag_add_dr_scan(4, fields, -1);
-               jtag_execute_queue();
-       } while (buf_get_u32(&access, 0, 1) != 1);
+               jtag_add_dr_scan(4, fields, jtag_get_end_state());
+
+               jtag_add_callback(arm_le_to_h_u32, (jtag_callback_data_t)value);
+
+               if ((retval = jtag_execute_queue()) != ERROR_OK)
+               {
+                       return retval;
+               }
+
+               if (buf_get_u32(&access, 0, 1) == 1)
+               {
+                       break;
+               }
+
+               /* 10ms timeout */
+               if ((timeval_ms()-then)>10)
+               {
+                       LOG_ERROR("cp15 read operation timed out");
+                       return ERROR_FAIL;
+               }
+       }
 
 #ifdef _DEBUG_INSTRUCTION_EXECUTION_
        LOG_DEBUG("addr: 0x%x value: %8.8x", address, *value);
 #endif
-       
-       arm_jtag_set_instr(jtag_info, 0xc, &arm926ejs_catch_broken_irscan);
+
+       arm_jtag_set_instr(jtag_info, 0xc, NULL);
 
        return ERROR_OK;
 }
 
-int arm926ejs_cp15_write(target_t *target, u32 op1, u32 op2, u32 CRn, u32 CRm, u32 value)
+static int arm926ejs_mrc(target_t *target, int cpnum, uint32_t op1,
+               uint32_t op2, uint32_t CRn, uint32_t CRm, uint32_t *value)
 {
-       armv4_5_common_t *armv4_5 = target->arch_info;
-       arm7_9_common_t *arm7_9 = armv4_5->arch_info;
+       if (cpnum != 15) {
+               LOG_ERROR("Only cp15 is supported");
+               return ERROR_FAIL;
+       }
+       return arm926ejs_cp15_read(target, op1, op2, CRn, CRm, value);
+}
+
+static int arm926ejs_cp15_write(target_t *target, uint32_t op1, uint32_t op2,
+               uint32_t CRn, uint32_t CRm, uint32_t value)
+{
+       int retval = ERROR_OK;
+       struct arm7_9_common_s *arm7_9 = target_to_arm7_9(target);
        arm_jtag_t *jtag_info = &arm7_9->jtag_info;
-       u32 address = ARM926EJS_CP15_ADDR(op1, op2, CRn, CRm);
-       scan_field_t fields[4];
-       u8 value_buf[4];
-       u8 address_buf[2];
-       u8 nr_w_buf = 1;
-       u8 access = 1;
-       
+       uint32_t address = ARM926EJS_CP15_ADDR(op1, op2, CRn, CRm);
+       struct scan_field fields[4];
+       uint8_t value_buf[4];
+       uint8_t address_buf[2];
+       uint8_t nr_w_buf = 1;
+       uint8_t access = 1;
+
        buf_set_u32(address_buf, 0, 14, address);
        buf_set_u32(value_buf, 0, 32, value);
-       
-       jtag_add_end_state(TAP_RTI);
-       arm_jtag_scann(jtag_info, 0xf);
+
+       jtag_set_end_state(TAP_IDLE);
+       if ((retval = arm_jtag_scann(jtag_info, 0xf)) != ERROR_OK)
+       {
+               return retval;
+       }
        arm_jtag_set_instr(jtag_info, jtag_info->intest_instr, NULL);
 
-       fields[0].device = jtag_info->chain_pos;
+       fields[0].tap = jtag_info->tap;
        fields[0].num_bits = 32;
        fields[0].out_value = value_buf;
-       fields[0].out_mask = NULL;
        fields[0].in_value = NULL;
-       fields[0].in_check_value = NULL;
-       fields[0].in_check_mask = NULL;
-       fields[0].in_handler = NULL;
-       fields[0].in_handler_priv = NULL;
 
-       fields[1].device = jtag_info->chain_pos;
+       fields[1].tap = jtag_info->tap;
        fields[1].num_bits = 1;
        fields[1].out_value = &access;
-       fields[1].out_mask = NULL;
        fields[1].in_value = &access;
-       fields[1].in_check_value = NULL;
-       fields[1].in_check_mask = NULL;
-       fields[1].in_handler = NULL;
-       fields[1].in_handler_priv = NULL;
 
-       fields[2].device = jtag_info->chain_pos;
+       fields[2].tap = jtag_info->tap;
        fields[2].num_bits = 14;
        fields[2].out_value = address_buf;
-       fields[2].out_mask = NULL;
        fields[2].in_value = NULL;
-       fields[2].in_check_value = NULL;
-       fields[2].in_check_mask = NULL;
-       fields[2].in_handler = NULL;
-       fields[2].in_handler_priv = NULL;
 
-       fields[3].device = jtag_info->chain_pos;
+       fields[3].tap = jtag_info->tap;
        fields[3].num_bits = 1;
        fields[3].out_value = &nr_w_buf;
-       fields[3].out_mask = NULL;
        fields[3].in_value = NULL;
-       fields[3].in_check_value = NULL;
-       fields[3].in_check_mask = NULL;
-       fields[3].in_handler = NULL;
-       fields[3].in_handler_priv = NULL;
-       
-       jtag_add_dr_scan(4, fields, -1);
-       /*TODO: add timeout*/
-       do
+
+       jtag_add_dr_scan(4, fields, jtag_get_end_state());
+
+       long long then = timeval_ms();
+
+       for (;;)
        {
                /* rescan with NOP, to wait for the access to complete */
                access = 0;
                nr_w_buf = 0;
-               jtag_add_dr_scan(4, fields, -1);
-               jtag_execute_queue();
-       } while (buf_get_u32(&access, 0, 1) != 1);
+               jtag_add_dr_scan(4, fields, jtag_get_end_state());
+               if ((retval = jtag_execute_queue()) != ERROR_OK)
+               {
+                       return retval;
+               }
+
+               if (buf_get_u32(&access, 0, 1) == 1)
+               {
+                       break;
+               }
+
+               /* 10ms timeout */
+               if ((timeval_ms()-then)>10)
+               {
+                       LOG_ERROR("cp15 write operation timed out");
+                       return ERROR_FAIL;
+               }
+       }
 
 #ifdef _DEBUG_INSTRUCTION_EXECUTION_
        LOG_DEBUG("addr: 0x%x value: %8.8x", address, value);
 #endif
 
-       arm_jtag_set_instr(jtag_info, 0xf, &arm926ejs_catch_broken_irscan);
+       arm_jtag_set_instr(jtag_info, 0xf, NULL);
 
        return ERROR_OK;
 }
 
-int arm926ejs_examine_debug_reason(target_t *target)
+static int arm926ejs_mcr(target_t *target, int cpnum, uint32_t op1,
+               uint32_t op2, uint32_t CRn, uint32_t CRm, uint32_t value)
 {
-       armv4_5_common_t *armv4_5 = target->arch_info;
-       arm7_9_common_t *arm7_9 = armv4_5->arch_info;
+       if (cpnum != 15) {
+               LOG_ERROR("Only cp15 is supported");
+               return ERROR_FAIL;
+       }
+       return arm926ejs_cp15_write(target, op1, op2, CRn, CRm, value);
+}
+
+static int arm926ejs_examine_debug_reason(target_t *target)
+{
+       struct arm7_9_common_s *arm7_9 = target_to_arm7_9(target);
        reg_t *dbg_stat = &arm7_9->eice_cache->reg_list[EICE_DBG_STAT];
        int debug_reason;
        int retval;
@@ -287,11 +239,17 @@ int arm926ejs_examine_debug_reason(target_t *target)
        embeddedice_read_reg(dbg_stat);
        if ((retval = jtag_execute_queue()) != ERROR_OK)
                return retval;
-       
+
+       /* Method-Of-Entry (MOE) field */
        debug_reason = buf_get_u32(dbg_stat->value, 6, 4);
-       
+
        switch (debug_reason)
        {
+               case 0:
+                       LOG_DEBUG("no *NEW* debug entry (?missed one?)");
+                       /* ... since last restart or debug reset ... */
+                       target->debug_reason = DBG_REASON_DBGRQ;
+                       break;
                case 1:
                        LOG_DEBUG("breakpoint from EICE unit 0");
                        target->debug_reason = DBG_REASON_BREAKPOINT;
@@ -333,26 +291,52 @@ int arm926ejs_examine_debug_reason(target_t *target)
                        target->debug_reason = DBG_REASON_DBGRQ;
                        break;
                case 11:
-                       LOG_ERROR("BUG: debug re-entry from system speed access shouldn't be handled here");
+                       LOG_DEBUG("debug re-entry from system speed access");
+                       /* This is normal when connecting to something that's
+                        * already halted, or in some related code paths, but
+                        * otherwise is surprising (and presumably wrong).
+                        */
+                       switch (target->debug_reason) {
+                       case DBG_REASON_DBGRQ:
+                               break;
+                       default:
+                               LOG_ERROR("unexpected -- debug re-entry");
+                               /* FALLTHROUGH */
+                       case DBG_REASON_UNDEFINED:
+                               target->debug_reason = DBG_REASON_DBGRQ;
+                               break;
+                       }
+                       break;
+               case 12:
+                       /* FIX!!!! here be dragons!!! We need to fail here so
+                        * the target will interpreted as halted but we won't
+                        * try to talk to it right now... a resume + halt seems
+                        * to sync things up again. Please send an email to
+                        * openocd development mailing list if you have hardware
+                        * to donate to look into this problem....
+                        */
+                       LOG_WARNING("WARNING: mystery debug reason MOE = 0xc. Try issuing a resume + halt.");
+                       target->debug_reason = DBG_REASON_DBGRQ;
                        break;
                default:
-                       LOG_ERROR("BUG: unknown debug reason: 0x%x", debug_reason);
+                       LOG_WARNING("WARNING: unknown debug reason: 0x%x", debug_reason);
+                       /* Oh agony! should we interpret this as a halt request or
+                        * that the target stopped on it's own accord?
+                        */
                        target->debug_reason = DBG_REASON_DBGRQ;
-                       retval = ERROR_TARGET_FAILURE;
+                       /* if we fail here, we won't talk to the target and it will
+                        * be reported to be in the halted state */
                        break;
        }
-       
-       return retval;
+
+       return ERROR_OK;
 }
 
-u32 arm926ejs_get_ttb(target_t *target)
+static uint32_t arm926ejs_get_ttb(target_t *target)
 {
-       armv4_5_common_t *armv4_5 = target->arch_info;
-       arm7_9_common_t *arm7_9 = armv4_5->arch_info;
-       arm9tdmi_common_t *arm9tdmi = arm7_9->arch_info;
-       arm926ejs_common_t *arm926ejs = arm9tdmi->arch_info;
+       struct arm926ejs_common_s *arm926ejs = target_to_arm926(target);
        int retval;
-       u32 ttb = 0x0;
+       uint32_t ttb = 0x0;
 
        if ((retval = arm926ejs->read_cp15(target, 0, 0, 2, 0, &ttb)) != ERROR_OK)
                return retval;
@@ -360,96 +344,89 @@ u32 arm926ejs_get_ttb(target_t *target)
        return ttb;
 }
 
-void arm926ejs_disable_mmu_caches(target_t *target, int mmu, int d_u_cache, int i_cache)
+static void arm926ejs_disable_mmu_caches(target_t *target, int mmu,
+               int d_u_cache, int i_cache)
 {
-       armv4_5_common_t *armv4_5 = target->arch_info;
-       arm7_9_common_t *arm7_9 = armv4_5->arch_info;
-       arm9tdmi_common_t *arm9tdmi = arm7_9->arch_info;
-       arm926ejs_common_t *arm926ejs = arm9tdmi->arch_info;
-       u32 cp15_control;
+       struct arm926ejs_common_s *arm926ejs = target_to_arm926(target);
+       uint32_t cp15_control;
 
        /* read cp15 control register */
        arm926ejs->read_cp15(target, 0, 0, 1, 0, &cp15_control);
        jtag_execute_queue();
-       
+
        if (mmu)
        {
                /* invalidate TLB */
                arm926ejs->write_cp15(target, 0, 0, 8, 7, 0x0);
-               
+
                cp15_control &= ~0x1U;
        }
-       
+
        if (d_u_cache)
        {
-               u32 debug_override;
-               /* read-modify-write CP15 debug override register 
+               uint32_t debug_override;
+               /* read-modify-write CP15 debug override register
                 * to enable "test and clean all" */
                arm926ejs->read_cp15(target, 0, 0, 15, 0, &debug_override);
                debug_override |= 0x80000;
                arm926ejs->write_cp15(target, 0, 0, 15, 0, debug_override);
-               
+
                /* clean and invalidate DCache */
                arm926ejs->write_cp15(target, 0, 0, 7, 5, 0x0);
 
-               /* write CP15 debug override register 
+               /* write CP15 debug override register
                 * to disable "test and clean all" */
                debug_override &= ~0x80000;
                arm926ejs->write_cp15(target, 0, 0, 15, 0, debug_override);
-               
+
                cp15_control &= ~0x4U;
        }
-       
+
        if (i_cache)
        {
                /* invalidate ICache */
                arm926ejs->write_cp15(target, 0, 0, 7, 5, 0x0);
-               
+
                cp15_control &= ~0x1000U;
        }
-       
+
        arm926ejs->write_cp15(target, 0, 0, 1, 0, cp15_control);
 }
 
-void arm926ejs_enable_mmu_caches(target_t *target, int mmu, int d_u_cache, int i_cache)
+static void arm926ejs_enable_mmu_caches(target_t *target, int mmu,
+               int d_u_cache, int i_cache)
 {
-       armv4_5_common_t *armv4_5 = target->arch_info;
-       arm7_9_common_t *arm7_9 = armv4_5->arch_info;
-       arm9tdmi_common_t *arm9tdmi = arm7_9->arch_info;
-       arm926ejs_common_t *arm926ejs = arm9tdmi->arch_info;
-       u32 cp15_control;
+       struct arm926ejs_common_s *arm926ejs = target_to_arm926(target);
+       uint32_t cp15_control;
 
        /* read cp15 control register */
        arm926ejs->read_cp15(target, 0, 0, 1, 0, &cp15_control);
        jtag_execute_queue();
-               
+
        if (mmu)
                cp15_control |= 0x1U;
-       
+
        if (d_u_cache)
                cp15_control |= 0x4U;
-       
+
        if (i_cache)
                cp15_control |= 0x1000U;
-       
+
        arm926ejs->write_cp15(target, 0, 0, 1, 0, cp15_control);
 }
 
-void arm926ejs_post_debug_entry(target_t *target)
+static void arm926ejs_post_debug_entry(target_t *target)
 {
-       armv4_5_common_t *armv4_5 = target->arch_info;
-       arm7_9_common_t *arm7_9 = armv4_5->arch_info;
-       arm9tdmi_common_t *arm9tdmi = arm7_9->arch_info;
-       arm926ejs_common_t *arm926ejs = arm9tdmi->arch_info;
+       struct arm926ejs_common_s *arm926ejs = target_to_arm926(target);
 
        /* examine cp15 control reg */
        arm926ejs->read_cp15(target, 0, 0, 1, 0, &arm926ejs->cp15_control_reg);
        jtag_execute_queue();
-       LOG_DEBUG("cp15_control_reg: %8.8x", arm926ejs->cp15_control_reg);
+       LOG_DEBUG("cp15_control_reg: %8.8" PRIx32 "", arm926ejs->cp15_control_reg);
 
        if (arm926ejs->armv4_5_mmu.armv4_5_cache.ctype == -1)
        {
-               u32 cache_type_reg;
+               uint32_t cache_type_reg;
                /* identify caches */
                arm926ejs->read_cp15(target, 0, 1, 0, 0, &cache_type_reg);
                jtag_execute_queue();
@@ -464,178 +441,190 @@ void arm926ejs_post_debug_entry(target_t *target)
        arm926ejs->read_cp15(target, 0, 0, 5, 0, &arm926ejs->d_fsr);
        arm926ejs->read_cp15(target, 0, 1, 5, 0, &arm926ejs->i_fsr);
        arm926ejs->read_cp15(target, 0, 0, 6, 0, &arm926ejs->d_far);
-       
-       LOG_DEBUG("D FSR: 0x%8.8x, D FAR: 0x%8.8x, I FSR: 0x%8.8x",
-               arm926ejs->d_fsr, arm926ejs->d_far, arm926ejs->i_fsr);  
 
+       LOG_DEBUG("D FSR: 0x%8.8" PRIx32 ", D FAR: 0x%8.8" PRIx32 ", I FSR: 0x%8.8" PRIx32 "",
+               arm926ejs->d_fsr, arm926ejs->d_far, arm926ejs->i_fsr);
 
-       u32 cache_dbg_ctrl;
-       
-       /* read-modify-write CP15 cache debug control register 
+       uint32_t cache_dbg_ctrl;
+
+       /* read-modify-write CP15 cache debug control register
         * to disable I/D-cache linefills and force WT */
        arm926ejs->read_cp15(target, 7, 0, 15, 0, &cache_dbg_ctrl);
        cache_dbg_ctrl |= 0x7;
        arm926ejs->write_cp15(target, 7, 0, 15, 0, cache_dbg_ctrl);
 }
 
-void arm926ejs_pre_restore_context(target_t *target)
+static void arm926ejs_pre_restore_context(target_t *target)
 {
-       armv4_5_common_t *armv4_5 = target->arch_info;
-       arm7_9_common_t *arm7_9 = armv4_5->arch_info;
-       arm9tdmi_common_t *arm9tdmi = arm7_9->arch_info;
-       arm926ejs_common_t *arm926ejs = arm9tdmi->arch_info;
+       struct arm926ejs_common_s *arm926ejs = target_to_arm926(target);
 
        /* restore i/d fault status and address register */
        arm926ejs->write_cp15(target, 0, 0, 5, 0, arm926ejs->d_fsr);
        arm926ejs->write_cp15(target, 0, 1, 5, 0, arm926ejs->i_fsr);
        arm926ejs->write_cp15(target, 0, 0, 6, 0, arm926ejs->d_far);
-       
-       u32 cache_dbg_ctrl;
-       
-       /* read-modify-write CP15 cache debug control register 
+
+       uint32_t cache_dbg_ctrl;
+
+       /* read-modify-write CP15 cache debug control register
         * to reenable I/D-cache linefills and disable WT */
        arm926ejs->read_cp15(target, 7, 0, 15, 0, &cache_dbg_ctrl);
        cache_dbg_ctrl &= ~0x7;
        arm926ejs->write_cp15(target, 7, 0, 15, 0, cache_dbg_ctrl);
 }
 
-int arm926ejs_get_arch_pointers(target_t *target, armv4_5_common_t **armv4_5_p, arm7_9_common_t **arm7_9_p, arm9tdmi_common_t **arm9tdmi_p, arm926ejs_common_t **arm926ejs_p)
+static const char arm926_not[] = "target is not an ARM926";
+
+static int arm926ejs_verify_pointer(struct command_context_s *cmd_ctx,
+               struct arm926ejs_common_s *arm926)
 {
-       armv4_5_common_t *armv4_5 = target->arch_info;
-       arm7_9_common_t *arm7_9;
-       arm9tdmi_common_t *arm9tdmi;
-       arm926ejs_common_t *arm926ejs;
-       
-       if (armv4_5->common_magic != ARMV4_5_COMMON_MAGIC)
-       {
-               return -1;
-       }
-       
-       arm7_9 = armv4_5->arch_info;
-       if (arm7_9->common_magic != ARM7_9_COMMON_MAGIC)
-       {
-               return -1;
-       }
-       
-       arm9tdmi = arm7_9->arch_info;
-       if (arm9tdmi->common_magic != ARM9TDMI_COMMON_MAGIC)
-       {
-               return -1;
-       }
-       
-       arm926ejs = arm9tdmi->arch_info;
-       if (arm926ejs->common_magic != ARM926EJS_COMMON_MAGIC)
-       {
-               return -1;
+       if (arm926->common_magic != ARM926EJS_COMMON_MAGIC) {
+               command_print(cmd_ctx, arm926_not);
+               return ERROR_TARGET_INVALID;
        }
-       
-       *armv4_5_p = armv4_5;
-       *arm7_9_p = arm7_9;
-       *arm9tdmi_p = arm9tdmi;
-       *arm926ejs_p = arm926ejs;
-       
        return ERROR_OK;
 }
 
+/** Logs summary of ARM926 state for a halted target. */
 int arm926ejs_arch_state(struct target_s *target)
 {
-       armv4_5_common_t *armv4_5 = target->arch_info;
-       arm7_9_common_t *arm7_9 = armv4_5->arch_info;
-       arm9tdmi_common_t *arm9tdmi = arm7_9->arch_info;
-       arm926ejs_common_t *arm926ejs = arm9tdmi->arch_info;
-       
-       char *state[] = 
+       static const char *state[] =
        {
                "disabled", "enabled"
        };
-       
-       if (armv4_5->common_magic != ARMV4_5_COMMON_MAGIC)
+
+       struct arm926ejs_common_s *arm926ejs = target_to_arm926(target);
+       struct armv4_5_common_s *armv4_5;
+
+       if (arm926ejs->common_magic != ARM926EJS_COMMON_MAGIC)
        {
-               LOG_ERROR("BUG: called for a non-ARMv4/5 target");
-               exit(-1);
+               LOG_ERROR("BUG: %s", arm926_not);
+               return ERROR_TARGET_INVALID;
        }
-       
-       LOG_USER(
-                       "target halted in %s state due to %s, current mode: %s\n"
-                       "cpsr: 0x%8.8x pc: 0x%8.8x\n"
+
+       armv4_5 = &arm926ejs->arm9tdmi_common.arm7_9_common.armv4_5_common;
+
+       LOG_USER("target halted in %s state due to %s, current mode: %s\n"
+                       "cpsr: 0x%8.8" PRIx32 " pc: 0x%8.8" PRIx32 "\n"
                        "MMU: %s, D-Cache: %s, I-Cache: %s",
                         armv4_5_state_strings[armv4_5->core_state],
-                        target_debug_reason_strings[target->debug_reason],
+                        Jim_Nvp_value2name_simple(nvp_target_debug_reason,target->debug_reason)->name,
                         armv4_5_mode_strings[armv4_5_mode_to_number(armv4_5->core_mode)],
                         buf_get_u32(armv4_5->core_cache->reg_list[ARMV4_5_CPSR].value, 0, 32),
                         buf_get_u32(armv4_5->core_cache->reg_list[15].value, 0, 32),
                         state[arm926ejs->armv4_5_mmu.mmu_enabled],
-                        state[arm926ejs->armv4_5_mmu.armv4_5_cache.d_u_cache_enabled], 
+                        state[arm926ejs->armv4_5_mmu.armv4_5_cache.d_u_cache_enabled],
                         state[arm926ejs->armv4_5_mmu.armv4_5_cache.i_cache_enabled]);
-       
+
        return ERROR_OK;
 }
 
 int arm926ejs_soft_reset_halt(struct target_s *target)
 {
-       armv4_5_common_t *armv4_5 = target->arch_info;
-       arm7_9_common_t *arm7_9 = armv4_5->arch_info;
-       arm9tdmi_common_t *arm9tdmi = arm7_9->arch_info;
-       arm926ejs_common_t *arm926ejs = arm9tdmi->arch_info;
+       int retval = ERROR_OK;
+       struct arm926ejs_common_s *arm926ejs = target_to_arm926(target);
+       struct arm7_9_common_s *arm7_9 = target_to_arm7_9(target);
+       struct armv4_5_common_s *armv4_5 = &arm7_9->armv4_5_common;
        reg_t *dbg_stat = &arm7_9->eice_cache->reg_list[EICE_DBG_STAT];
-       int i;
-       
-       target_halt(target);
-       
-       for (i=0; i<10; i++)
+
+       if ((retval = target_halt(target)) != ERROR_OK)
+       {
+               return retval;
+       }
+
+       long long then = timeval_ms();
+       int timeout;
+       while (!(timeout = ((timeval_ms()-then) > 1000)))
        {
                if (buf_get_u32(dbg_stat->value, EICE_DBG_STATUS_DBGACK, 1) == 0)
                {
                        embeddedice_read_reg(dbg_stat);
-                       jtag_execute_queue();
+                       if ((retval = jtag_execute_queue()) != ERROR_OK)
+                       {
+                               return retval;
+                       }
                }  else
                {
                        break;
                }
-               /* do not eat all CPU, time out after 1 se*/
-               usleep(100*1000);
+               if (debug_level >= 1)
+               {
+                       /* do not eat all CPU, time out after 1 se*/
+                       alive_sleep(100);
+               } else
+               {
+                       keep_alive();
+               }
        }
-       if (i==10)
+       if (timeout)
        {
                LOG_ERROR("Failed to halt CPU after 1 sec");
                return ERROR_TARGET_TIMEOUT;
        }
-       
+
        target->state = TARGET_HALTED;
-       
+
        /* SVC, ARM state, IRQ and FIQ disabled */
        buf_set_u32(armv4_5->core_cache->reg_list[ARMV4_5_CPSR].value, 0, 8, 0xd3);
        armv4_5->core_cache->reg_list[ARMV4_5_CPSR].dirty = 1;
        armv4_5->core_cache->reg_list[ARMV4_5_CPSR].valid = 1;
-       
+
        /* start fetching from 0x0 */
        buf_set_u32(armv4_5->core_cache->reg_list[15].value, 0, 32, 0x0);
        armv4_5->core_cache->reg_list[15].dirty = 1;
        armv4_5->core_cache->reg_list[15].valid = 1;
-       
+
        armv4_5->core_mode = ARMV4_5_MODE_SVC;
        armv4_5->core_state = ARMV4_5_STATE_ARM;
-       
+
        arm926ejs_disable_mmu_caches(target, 1, 1, 1);
        arm926ejs->armv4_5_mmu.mmu_enabled = 0;
        arm926ejs->armv4_5_mmu.armv4_5_cache.d_u_cache_enabled = 0;
        arm926ejs->armv4_5_mmu.armv4_5_cache.i_cache_enabled = 0;
 
-       target_call_event_callbacks(target, TARGET_EVENT_HALTED);
-       
-       return ERROR_OK;
+       return target_call_event_callbacks(target, TARGET_EVENT_HALTED);
 }
 
-int arm926ejs_write_memory(struct target_s *target, u32 address, u32 size, u32 count, u8 *buffer)
+/** Writes a buffer, in the specified word size, with current MMU settings. */
+int arm926ejs_write_memory(struct target_s *target, uint32_t address,
+               uint32_t size, uint32_t count, uint8_t *buffer)
 {
        int retval;
-       armv4_5_common_t *armv4_5 = target->arch_info;
-       arm7_9_common_t *arm7_9 = armv4_5->arch_info;
-       arm9tdmi_common_t *arm9tdmi = arm7_9->arch_info;
-       arm926ejs_common_t *arm926ejs = arm9tdmi->arch_info;
-       
-       if ((retval = arm7_9_write_memory(target, address, size, count, buffer)) != ERROR_OK)
-               return retval;
+       struct arm926ejs_common_s *arm926ejs = target_to_arm926(target);
+
+       /* FIX!!!! this should be cleaned up and made much more general. The
+        * plan is to write up and test on arm926ejs specifically and
+        * then generalize and clean up afterwards. */
+       if (arm926ejs->armv4_5_mmu.mmu_enabled && (count == 1) && ((size==2) || (size==4)))
+       {
+               /* special case the handling of single word writes to bypass MMU
+                * to allow implementation of breakpoints in memory marked read only
+                * by MMU */
+               if (arm926ejs->armv4_5_mmu.armv4_5_cache.d_u_cache_enabled)
+               {
+                       /* flush and invalidate data cache
+                        *
+                        * MCR p15,0,p,c7,c10,1 - clean cache line using virtual address
+                        *
+                        */
+                       retval = arm926ejs->write_cp15(target, 0, 1, 7, 10, address&~0x3);
+                       if (retval != ERROR_OK)
+                               return retval;
+               }
+
+               uint32_t pa;
+               retval = target->type->virt2phys(target, address, &pa);
+               if (retval != ERROR_OK)
+                       return retval;
+
+               /* write directly to physical memory bypassing any read only MMU bits, etc. */
+               retval = armv4_5_mmu_write_physical(target, &arm926ejs->armv4_5_mmu, pa, size, count, buffer);
+               if (retval != ERROR_OK)
+                       return retval;
+       } else
+       {
+               if ((retval = arm7_9_write_memory(target, address, size, count, buffer)) != ERROR_OK)
+                       return retval;
+       }
 
        /* If ICache is enabled, we have to invalidate affected ICache lines
         * the DCache is forced to write-through, so we don't have to clean it here
@@ -657,35 +646,41 @@ int arm926ejs_write_memory(struct target_s *target, u32 address, u32 size, u32 c
        return retval;
 }
 
-int arm926ejs_init_target(struct command_context_s *cmd_ctx, struct target_s *target)
+static int arm926ejs_write_phys_memory(struct target_s *target,
+               uint32_t address, uint32_t size,
+               uint32_t count, uint8_t *buffer)
 {
-       arm9tdmi_init_target(cmd_ctx, target);
-               
-       return ERROR_OK;
-       
+       struct arm926ejs_common_s *arm926ejs = target_to_arm926(target);
+
+       return armv4_5_mmu_write_physical(target, &arm926ejs->armv4_5_mmu,
+                       address, size, count, buffer);
 }
 
-int arm926ejs_quit()
+static int arm926ejs_read_phys_memory(struct target_s *target,
+               uint32_t address, uint32_t size,
+               uint32_t count, uint8_t *buffer)
 {
-       
-       return ERROR_OK;
+       struct arm926ejs_common_s *arm926ejs = target_to_arm926(target);
+
+       return armv4_5_mmu_read_physical(target, &arm926ejs->armv4_5_mmu,
+                       address, size, count, buffer);
 }
 
-int arm926ejs_init_arch_info(target_t *target, arm926ejs_common_t *arm926ejs, int chain_pos, char *variant)
+int arm926ejs_init_arch_info(target_t *target, arm926ejs_common_t *arm926ejs,
+               struct jtag_tap *tap)
 {
        arm9tdmi_common_t *arm9tdmi = &arm926ejs->arm9tdmi_common;
        arm7_9_common_t *arm7_9 = &arm9tdmi->arm7_9_common;
-       
+
        /* initialize arm9tdmi specific info (including arm7_9 and armv4_5)
         */
-       arm9tdmi_init_arch_info(target, arm9tdmi, chain_pos, variant);
+       arm9tdmi_init_arch_info(target, arm9tdmi, tap);
 
-       arm9tdmi->arch_info = arm926ejs;
        arm926ejs->common_magic = ARM926EJS_COMMON_MAGIC;
-       
+
        arm7_9->post_debug_entry = arm926ejs_post_debug_entry;
        arm7_9->pre_restore_context = arm926ejs_pre_restore_context;
-       
+
        arm926ejs->read_cp15 = arm926ejs_cp15_read;
        arm926ejs->write_cp15 = arm926ejs_cp15_write;
        arm926ejs->armv4_5_mmu.armv4_5_cache.ctype = -1;
@@ -696,80 +691,33 @@ int arm926ejs_init_arch_info(target_t *target, arm926ejs_common_t *arm926ejs, in
        arm926ejs->armv4_5_mmu.enable_mmu_caches = arm926ejs_enable_mmu_caches;
        arm926ejs->armv4_5_mmu.has_tiny_pages = 1;
        arm926ejs->armv4_5_mmu.mmu_enabled = 0;
-       
+
        arm7_9->examine_debug_reason = arm926ejs_examine_debug_reason;
-       
+
        /* The ARM926EJ-S implements the ARMv5TE architecture which
         * has the BKPT instruction, so we don't have to use a watchpoint comparator
         */
        arm7_9->arm_bkpt = ARMV5_BKPT(0x0);
        arm7_9->thumb_bkpt = ARMV5_T_BKPT(0x0) & 0xffff;
-       
-       arm7_9->sw_bkpts_use_wp = 0;
-       arm7_9->sw_bkpts_enabled = 1;
-       
-       return ERROR_OK;
-}
-
-int arm926ejs_target_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc, struct target_s *target)
-{
-       int chain_pos;
-       char *variant = NULL;
-       arm926ejs_common_t *arm926ejs = malloc(sizeof(arm926ejs_common_t));
-       memset(arm926ejs, 0, sizeof(*arm926ejs));
-       
-       if (argc < 4)
-       {
-               LOG_ERROR("'target arm926ejs' requires at least one additional argument");
-               exit(-1);
-       }
-       
-       chain_pos = strtoul(args[3], NULL, 0);
-       
-       if (argc >= 5)
-               variant = args[4];
-       
-       LOG_DEBUG("chain_pos: %i, variant: %s", chain_pos, variant);
-       
-       arm926ejs_init_arch_info(target, arm926ejs, chain_pos, variant);
 
        return ERROR_OK;
 }
 
-int arm926ejs_register_commands(struct command_context_s *cmd_ctx)
+static int arm926ejs_target_create(struct target_s *target, Jim_Interp *interp)
 {
-       int retval;
-       command_t *arm926ejs_cmd;
-       
-               
-       retval = arm9tdmi_register_commands(cmd_ctx);
-       
-       arm926ejs_cmd = register_command(cmd_ctx, NULL, "arm926ejs", NULL, COMMAND_ANY, "arm926ejs specific commands");
-
-       register_command(cmd_ctx, arm926ejs_cmd, "cp15", arm926ejs_handle_cp15_command, COMMAND_EXEC, "display/modify cp15 register <opcode_1> <opcode_2> <CRn> <CRm> [value]");
-       
-       register_command(cmd_ctx, arm926ejs_cmd, "cache_info", arm926ejs_handle_cache_info_command, COMMAND_EXEC, "display information about target caches");
-       register_command(cmd_ctx, arm926ejs_cmd, "virt2phys", arm926ejs_handle_virt2phys_command, COMMAND_EXEC, "translate va to pa <va>");
-
-       register_command(cmd_ctx, arm926ejs_cmd, "mdw_phys", arm926ejs_handle_md_phys_command, COMMAND_EXEC, "display memory words <physical addr> [count]");
-       register_command(cmd_ctx, arm926ejs_cmd, "mdh_phys", arm926ejs_handle_md_phys_command, COMMAND_EXEC, "display memory half-words <physical addr> [count]");
-       register_command(cmd_ctx, arm926ejs_cmd, "mdb_phys", arm926ejs_handle_md_phys_command, COMMAND_EXEC, "display memory bytes <physical addr> [count]");
+       arm926ejs_common_t *arm926ejs = calloc(1,sizeof(arm926ejs_common_t));
 
-       register_command(cmd_ctx, arm926ejs_cmd, "mww_phys", arm926ejs_handle_mw_phys_command, COMMAND_EXEC, "write memory word <physical addr> <value>");
-       register_command(cmd_ctx, arm926ejs_cmd, "mwh_phys", arm926ejs_handle_mw_phys_command, COMMAND_EXEC, "write memory half-word <physical addr> <value>");
-       register_command(cmd_ctx, arm926ejs_cmd, "mwb_phys", arm926ejs_handle_mw_phys_command, COMMAND_EXEC, "write memory byte <physical addr> <value>");
+       /* ARM9EJ-S core always reports 0x1 in Capture-IR */
+       target->tap->ir_capture_mask = 0x0f;
 
-       return ERROR_OK;
+       return arm926ejs_init_arch_info(target, arm926ejs, target->tap);
 }
 
-int arm926ejs_handle_cp15_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
+COMMAND_HANDLER(arm926ejs_handle_cp15_command)
 {
        int retval;
        target_t *target = get_current_target(cmd_ctx);
-       armv4_5_common_t *armv4_5;
-       arm7_9_common_t *arm7_9;
-       arm9tdmi_common_t *arm9tdmi;
-       arm926ejs_common_t *arm926ejs;
+       struct arm926ejs_common_s *arm926ejs = target_to_arm926(target);
        int opcode_1;
        int opcode_2;
        int CRn;
@@ -780,162 +728,74 @@ int arm926ejs_handle_cp15_command(struct command_context_s *cmd_ctx, char *cmd,
                command_print(cmd_ctx, "usage: arm926ejs cp15 <opcode_1> <opcode_2> <CRn> <CRm> [value]");
                return ERROR_OK;
        }
-       
-       opcode_1 = strtoul(args[0], NULL, 0);
-       opcode_2 = strtoul(args[1], NULL, 0);
-       CRn = strtoul(args[2], NULL, 0);
-       CRm = strtoul(args[3], NULL, 0);
 
-       if (arm926ejs_get_arch_pointers(target, &armv4_5, &arm7_9, &arm9tdmi, &arm926ejs) != ERROR_OK)
-       {
-               command_print(cmd_ctx, "current target isn't an ARM926EJ-S target");
-               return ERROR_OK;
-       }
-       
+       COMMAND_PARSE_NUMBER(int, args[0], opcode_1);
+       COMMAND_PARSE_NUMBER(int, args[1], opcode_2);
+       COMMAND_PARSE_NUMBER(int, args[2], CRn);
+       COMMAND_PARSE_NUMBER(int, args[3], CRm);
+
+       retval = arm926ejs_verify_pointer(cmd_ctx, arm926ejs);
+       if (retval != ERROR_OK)
+               return retval;
+
        if (target->state != TARGET_HALTED)
        {
-               command_print(cmd_ctx, "target must be stopped for \"%s\" command", cmd);
+               command_print(cmd_ctx, "target must be stopped for \"%s\" command", CMD_NAME);
                return ERROR_OK;
        }
-       
+
        if (argc == 4)
        {
-               u32 value;
+               uint32_t value;
                if ((retval = arm926ejs->read_cp15(target, opcode_1, opcode_2, CRn, CRm, &value)) != ERROR_OK)
                {
                        command_print(cmd_ctx, "couldn't access register");
                        return ERROR_OK;
                }
-               jtag_execute_queue();
-               
-               command_print(cmd_ctx, "%i %i %i %i: %8.8x", opcode_1, opcode_2, CRn, CRm, value);
+               if ((retval = jtag_execute_queue()) != ERROR_OK)
+               {
+                       return retval;
+               }
+
+               command_print(cmd_ctx, "%i %i %i %i: %8.8" PRIx32 "", opcode_1, opcode_2, CRn, CRm, value);
        }
        else
        {
-               u32 value = strtoul(args[4], NULL, 0);
+               uint32_t value;
+               COMMAND_PARSE_NUMBER(u32, args[4], value);
                if ((retval = arm926ejs->write_cp15(target, opcode_1, opcode_2, CRn, CRm, value)) != ERROR_OK)
                {
                        command_print(cmd_ctx, "couldn't access register");
                        return ERROR_OK;
                }
-               command_print(cmd_ctx, "%i %i %i %i: %8.8x", opcode_1, opcode_2, CRn, CRm, value);
+               command_print(cmd_ctx, "%i %i %i %i: %8.8" PRIx32 "", opcode_1, opcode_2, CRn, CRm, value);
        }
 
        return ERROR_OK;
 }
 
-int arm926ejs_handle_cache_info_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
+COMMAND_HANDLER(arm926ejs_handle_cache_info_command)
 {
+       int retval;
        target_t *target = get_current_target(cmd_ctx);
-       armv4_5_common_t *armv4_5;
-       arm7_9_common_t *arm7_9;
-       arm9tdmi_common_t *arm9tdmi;
-       arm926ejs_common_t *arm926ejs;
-       
-       if (arm926ejs_get_arch_pointers(target, &armv4_5, &arm7_9, &arm9tdmi, &arm926ejs) != ERROR_OK)
-       {
-               command_print(cmd_ctx, "current target isn't an ARM926EJ-S target");
-               return ERROR_OK;
-       }
-       
-       return armv4_5_handle_cache_info_command(cmd_ctx, &arm926ejs->armv4_5_mmu.armv4_5_cache);
-}
-
-int arm926ejs_handle_virt2phys_command(command_context_t *cmd_ctx, char *cmd, char **args, int argc)
-{      
-       target_t *target = get_current_target(cmd_ctx);
-       armv4_5_common_t *armv4_5;
-       arm7_9_common_t *arm7_9;
-       arm9tdmi_common_t *arm9tdmi;
-       arm926ejs_common_t *arm926ejs;
-       arm_jtag_t *jtag_info;
-
-       if (arm926ejs_get_arch_pointers(target, &armv4_5, &arm7_9, &arm9tdmi, &arm926ejs) != ERROR_OK)
-       {
-               command_print(cmd_ctx, "current target isn't an ARM926EJ-S target");
-               return ERROR_OK;
-       }
-       
-       jtag_info = &arm7_9->jtag_info;
-       
-       if (target->state != TARGET_HALTED)
-       {
-               command_print(cmd_ctx, "target must be stopped for \"%s\" command", cmd);
-               return ERROR_OK;
-       }
-               
-       return armv4_5_mmu_handle_virt2phys_command(cmd_ctx, cmd, args, argc, target, &arm926ejs->armv4_5_mmu);
-}
+       struct arm926ejs_common_s *arm926ejs = target_to_arm926(target);
 
-int arm926ejs_handle_md_phys_command(command_context_t *cmd_ctx, char *cmd, char **args, int argc)
-{      
-       target_t *target = get_current_target(cmd_ctx);
-       armv4_5_common_t *armv4_5;
-       arm7_9_common_t *arm7_9;
-       arm9tdmi_common_t *arm9tdmi;
-       arm926ejs_common_t *arm926ejs;
-       arm_jtag_t *jtag_info;
+       retval = arm926ejs_verify_pointer(cmd_ctx, arm926ejs);
+       if (retval != ERROR_OK)
+               return retval;
 
-       if (arm926ejs_get_arch_pointers(target, &armv4_5, &arm7_9, &arm9tdmi, &arm926ejs) != ERROR_OK)
-       {
-               command_print(cmd_ctx, "current target isn't an ARM926EJ-S target");
-               return ERROR_OK;
-       }
-       
-       jtag_info = &arm7_9->jtag_info;
-       
-       if (target->state != TARGET_HALTED)
-       {
-               command_print(cmd_ctx, "target must be stopped for \"%s\" command", cmd);
-               return ERROR_OK;
-       }
-       
-       return armv4_5_mmu_handle_md_phys_command(cmd_ctx, cmd, args, argc, target, &arm926ejs->armv4_5_mmu);
+       return armv4_5_handle_cache_info_command(cmd_ctx, &arm926ejs->armv4_5_mmu.armv4_5_cache);
 }
 
-int arm926ejs_handle_mw_phys_command(command_context_t *cmd_ctx, char *cmd, char **args, int argc)
-{      
-       target_t *target = get_current_target(cmd_ctx);
-       armv4_5_common_t *armv4_5;
-       arm7_9_common_t *arm7_9;
-       arm9tdmi_common_t *arm9tdmi;
-       arm926ejs_common_t *arm926ejs;
-       arm_jtag_t *jtag_info;
-
-       if (arm926ejs_get_arch_pointers(target, &armv4_5, &arm7_9, &arm9tdmi, &arm926ejs) != ERROR_OK)
-       {
-               command_print(cmd_ctx, "current target isn't an ARM926EJ-S target");
-               return ERROR_OK;
-       }
-       
-       jtag_info = &arm7_9->jtag_info;
-       
-       if (target->state != TARGET_HALTED)
-       {
-               command_print(cmd_ctx, "target must be stopped for \"%s\" command", cmd);
-               return ERROR_OK;
-       }
-       
-       return armv4_5_mmu_handle_mw_phys_command(cmd_ctx, cmd, args, argc, target, &arm926ejs->armv4_5_mmu);
-}
-static int arm926ejs_virt2phys(struct target_s *target, u32 virtual, u32 *physical)
+static int arm926ejs_virt2phys(struct target_s *target, uint32_t virtual, uint32_t *physical)
 {
-       int retval;
        int type;
-       u32 cb;
+       uint32_t cb;
        int domain;
-       u32 ap;
-       
-       armv4_5_common_t *armv4_5;
-       arm7_9_common_t *arm7_9;
-       arm9tdmi_common_t *arm9tdmi;
-       arm926ejs_common_t *arm926ejs;
-       retval= arm926ejs_get_arch_pointers(target, &armv4_5, &arm7_9, &arm9tdmi, &arm926ejs);
-       if (retval != ERROR_OK)
-       {
-               return retval;
-       }
-       u32 ret = armv4_5_mmu_translate_va(target, &arm926ejs->armv4_5_mmu, virtual, &type, &cb, &domain, &ap);
+       uint32_t ap;
+       struct arm926ejs_common_s *arm926ejs = target_to_arm926(target);
+
+       uint32_t ret = armv4_5_mmu_translate_va(target, &arm926ejs->armv4_5_mmu, virtual, &type, &cb, &domain, &ap);
        if (type == -1)
        {
                return ret;
@@ -946,9 +806,8 @@ static int arm926ejs_virt2phys(struct target_s *target, u32 virtual, u32 *physic
 
 static int arm926ejs_mmu(struct target_s *target, int *enabled)
 {
-       armv4_5_common_t *armv4_5 = target->arch_info;
-       arm926ejs_common_t *arm926ejs = armv4_5->arch_info;
-       
+       struct arm926ejs_common_s *arm926ejs = target_to_arm926(target);
+
        if (target->state != TARGET_HALTED)
        {
                LOG_ERROR("Target not halted");
@@ -957,3 +816,73 @@ static int arm926ejs_mmu(struct target_s *target, int *enabled)
        *enabled = arm926ejs->armv4_5_mmu.mmu_enabled;
        return ERROR_OK;
 }
+
+/** Registers commands to access coprocessor, cache, and debug resources.  */
+int arm926ejs_register_commands(struct command_context_s *cmd_ctx)
+{
+       int retval;
+       command_t *arm926ejs_cmd;
+
+       retval = arm9tdmi_register_commands(cmd_ctx);
+
+       arm926ejs_cmd = register_command(cmd_ctx, NULL, "arm926ejs",
+               NULL, COMMAND_ANY,
+               "arm926ejs specific commands");
+
+       register_command(cmd_ctx, arm926ejs_cmd, "cp15",
+               arm926ejs_handle_cp15_command, COMMAND_EXEC,
+               "display/modify cp15 register "
+               "<opcode_1> <opcode_2> <CRn> <CRm> [value]");
+
+       register_command(cmd_ctx, arm926ejs_cmd, "cache_info",
+               arm926ejs_handle_cache_info_command, COMMAND_EXEC,
+               "display information about target caches");
+
+       return retval;
+}
+
+/** Holds methods for ARM926 targets. */
+target_type_t arm926ejs_target =
+{
+       .name = "arm926ejs",
+
+       .poll = arm7_9_poll,
+       .arch_state = arm926ejs_arch_state,
+
+       .target_request_data = arm7_9_target_request_data,
+
+       .halt = arm7_9_halt,
+       .resume = arm7_9_resume,
+       .step = arm7_9_step,
+
+       .assert_reset = arm7_9_assert_reset,
+       .deassert_reset = arm7_9_deassert_reset,
+       .soft_reset_halt = arm926ejs_soft_reset_halt,
+
+       .get_gdb_reg_list = armv4_5_get_gdb_reg_list,
+
+       .read_memory = arm7_9_read_memory,
+       .write_memory = arm926ejs_write_memory,
+       .bulk_write_memory = arm7_9_bulk_write_memory,
+       .checksum_memory = arm7_9_checksum_memory,
+       .blank_check_memory = arm7_9_blank_check_memory,
+
+       .run_algorithm = armv4_5_run_algorithm,
+
+       .add_breakpoint = arm7_9_add_breakpoint,
+       .remove_breakpoint = arm7_9_remove_breakpoint,
+       .add_watchpoint = arm7_9_add_watchpoint,
+       .remove_watchpoint = arm7_9_remove_watchpoint,
+
+       .register_commands = arm926ejs_register_commands,
+       .target_create = arm926ejs_target_create,
+       .init_target = arm9tdmi_init_target,
+       .examine = arm9tdmi_examine,
+       .virt2phys = arm926ejs_virt2phys,
+       .mmu = arm926ejs_mmu,
+
+       .read_phys_memory = arm926ejs_read_phys_memory,
+       .write_phys_memory = arm926ejs_write_phys_memory,
+       .mrc = arm926ejs_mrc,
+       .mcr = arm926ejs_mcr,
+};