]> git.sur5r.net Git - openocd/blobdiff - src/target/cortex_a.c
target: cortex_a: fix segfault when SPSR is not properly handled
[openocd] / src / target / cortex_a.c
index 8a0d38bcab6cfb357a890bede23ea2d6b1d8eb1e..8c8a2b79ea5719ebbf5e8a7f30a2ac2951f7af7d 100644 (file)
@@ -18,7 +18,7 @@
  *   michel.jaouen@stericsson.com : smp minimum support                    *
  *                                                                         *
  *   Copyright (C) Broadcom 2012                                           *
- *   ehunter@broadcom.com : Cortex R4 support                              *
+ *   ehunter@broadcom.com : Cortex-R4 support                              *
  *                                                                         *
  *   Copyright (C) 2013 Kamal Dasu                                         *
  *   kdasu.kdev@gmail.com                                                  *
@@ -34,9 +34,7 @@
  *   GNU General Public License for more details.                          *
  *                                                                         *
  *   You should have received a copy of the GNU General Public License     *
- *   along with this program; if not, write to the                         *
- *   Free Software Foundation, Inc.,                                       *
- *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.           *
+ *   along with this program.  If not, see <http://www.gnu.org/licenses/>. *
  *                                                                         *
  *   Cortex-A8(tm) TRM, ARM DDI 0344H                                      *
  *   Cortex-A9(tm) TRM, ARM DDI 0407F                                      *
@@ -55,6 +53,8 @@
 #include "target_request.h"
 #include "target_type.h"
 #include "arm_opcodes.h"
+#include "arm_semihosting.h"
+#include "jtag/swd.h"
 #include <helper/time_support.h>
 
 static int cortex_a_poll(struct target *target);
@@ -76,7 +76,7 @@ static int cortex_a_mmu(struct target *target, int *enabled);
 static int cortex_a_mmu_modify(struct target *target, int enable);
 static int cortex_a_virt2phys(struct target *target,
        uint32_t virt, uint32_t *phys);
-static int cortex_a_read_apb_ab_memory(struct target *target,
+static int cortex_a_read_cpu_memory(struct target *target,
        uint32_t address, uint32_t size, uint32_t count, uint8_t *buffer);
 
 
@@ -196,32 +196,6 @@ static int cortex_a_mmu_modify(struct target *target, int enable)
        return retval;
 }
 
-/*
- * Cortex-A Basic debug access, very low level assumes state is saved
- */
-static int cortex_a8_init_debug_access(struct target *target)
-{
-       struct armv7a_common *armv7a = target_to_armv7a(target);
-       int retval;
-
-       LOG_DEBUG(" ");
-
-       /* Unlocking the debug registers for modification
-        * The debugport might be uninitialised so try twice */
-       retval = mem_ap_write_atomic_u32(armv7a->debug_ap,
-                       armv7a->debug_base + CPUDBG_LOCKACCESS, 0xC5ACCE55);
-       if (retval != ERROR_OK) {
-               /* try again */
-               retval = mem_ap_write_atomic_u32(armv7a->debug_ap,
-                               armv7a->debug_base + CPUDBG_LOCKACCESS, 0xC5ACCE55);
-               if (retval == ERROR_OK)
-                       LOG_USER(
-                               "Locking debug access failed on first, but succeeded on second try.");
-       }
-
-       return retval;
-}
-
 /*
  * Cortex-A Basic debug access, very low level assumes state is saved
  */
@@ -229,47 +203,11 @@ static int cortex_a_init_debug_access(struct target *target)
 {
        struct armv7a_common *armv7a = target_to_armv7a(target);
        int retval;
-       uint32_t dbg_osreg;
-       uint32_t cortex_part_num;
-       struct cortex_a_common *cortex_a = target_to_cortex_a(target);
-
-       LOG_DEBUG(" ");
-       cortex_part_num = (cortex_a->cpuid & CORTEX_A_MIDR_PARTNUM_MASK) >>
-               CORTEX_A_MIDR_PARTNUM_SHIFT;
-
-       switch (cortex_part_num) {
-       case CORTEX_A7_PARTNUM:
-       case CORTEX_A15_PARTNUM:
-               retval = mem_ap_read_atomic_u32(armv7a->debug_ap,
-                                                   armv7a->debug_base + CPUDBG_OSLSR,
-                                                   &dbg_osreg);
-               if (retval != ERROR_OK)
-                       return retval;
-
-               LOG_DEBUG("DBGOSLSR  0x%" PRIx32, dbg_osreg);
-
-               if (dbg_osreg & CPUDBG_OSLAR_LK_MASK)
-                       /* Unlocking the DEBUG OS registers for modification */
-                       retval = mem_ap_write_atomic_u32(armv7a->debug_ap,
-                                                            armv7a->debug_base + CPUDBG_OSLAR,
-                                                            0);
-               break;
-
-       case CORTEX_A5_PARTNUM:
-       case CORTEX_A8_PARTNUM:
-       case CORTEX_A9_PARTNUM:
-       default:
-               retval = cortex_a8_init_debug_access(target);
-       }
-
-       if (retval != ERROR_OK)
-               return retval;
-       /* Clear Sticky Power Down status Bit in PRSR to enable access to
-          the registers in the Core Power Domain */
-       retval = mem_ap_read_atomic_u32(armv7a->debug_ap,
-                       armv7a->debug_base + CPUDBG_PRSR, &dbg_osreg);
-       LOG_DEBUG("target->coreid %" PRId32 " DBGPRSR  0x%" PRIx32, target->coreid, dbg_osreg);
 
+       /* lock memory-mapped access to debug registers to prevent
+        * software interference */
+       retval = mem_ap_write_atomic_u32(armv7a->debug_ap,
+                       armv7a->debug_base + CPUDBG_LOCKACCESS, 0);
        if (retval != ERROR_OK)
                return retval;
 
@@ -299,7 +237,7 @@ static int cortex_a_wait_instrcmpl(struct target *target, uint32_t *dscr, bool f
         * Writes final value of DSCR into *dscr. Pass force to force always
         * reading DSCR at least once. */
        struct armv7a_common *armv7a = target_to_armv7a(target);
-       long long then = timeval_ms();
+       int64_t then = timeval_ms();
        while ((*dscr & DSCR_INSTR_COMP) == 0 || force) {
                force = false;
                int retval = mem_ap_read_atomic_u32(armv7a->debug_ap,
@@ -342,7 +280,7 @@ static int cortex_a_exec_opcode(struct target *target,
        if (retval != ERROR_OK)
                return retval;
 
-       long long then = timeval_ms();
+       int64_t then = timeval_ms();
        do {
                retval = mem_ap_read_atomic_u32(armv7a->debug_ap,
                                armv7a->debug_base + CPUDBG_DSCR, &dscr);
@@ -431,7 +369,7 @@ static int cortex_a_dap_read_coreregister_u32(struct target *target,
        }
 
        /* Wait for DTRRXfull then read DTRRTX */
-       long long then = timeval_ms();
+       int64_t then = timeval_ms();
        while ((dscr & DSCR_DTR_TX_FULL) == 0) {
                retval = mem_ap_read_atomic_u32(armv7a->debug_ap,
                                armv7a->debug_base + CPUDBG_DSCR, &dscr);
@@ -574,7 +512,7 @@ static int cortex_a_read_dcc(struct cortex_a_common *a, uint32_t *data,
                dscr = *dscr_p;
 
        /* Wait for DTRRXfull */
-       long long then = timeval_ms();
+       int64_t then = timeval_ms();
        while ((dscr & DSCR_DTR_TX_FULL) == 0) {
                retval = mem_ap_read_atomic_u32(a->armv7a_common.debug_ap,
                                a->armv7a_common.debug_base + CPUDBG_DSCR,
@@ -606,7 +544,7 @@ static int cortex_a_dpm_prepare(struct arm_dpm *dpm)
        int retval;
 
        /* set up invariant:  INSTR_COMP is set after ever DPM operation */
-       long long then = timeval_ms();
+       int64_t then = timeval_ms();
        for (;; ) {
                retval = mem_ap_read_atomic_u32(a->armv7a_common.debug_ap,
                                a->armv7a_common.debug_base + CPUDBG_DSCR,
@@ -854,7 +792,8 @@ static int cortex_a_halt_smp(struct target *target)
        head = target->head;
        while (head != (struct target_list *)NULL) {
                curr = head->target;
-               if ((curr != target) && (curr->state != TARGET_HALTED))
+               if ((curr != target) && (curr->state != TARGET_HALTED)
+                       && target_was_examined(curr))
                        retval += cortex_a_halt(curr);
                head = head->next;
        }
@@ -917,6 +856,10 @@ static int cortex_a_poll(struct target *target)
                                        if (retval != ERROR_OK)
                                                return retval;
                                }
+
+                               if (arm_semihosting(target, &retval) != 0)
+                                       return retval;
+
                                target_call_event_callbacks(target,
                                        TARGET_EVENT_HALTED);
                        }
@@ -974,7 +917,7 @@ static int cortex_a_halt(struct target *target)
        if (retval != ERROR_OK)
                return retval;
 
-       long long then = timeval_ms();
+       int64_t then = timeval_ms();
        for (;; ) {
                retval = mem_ap_read_atomic_u32(armv7a->debug_ap,
                                armv7a->debug_base + CPUDBG_DSCR, &dscr);
@@ -1121,7 +1064,7 @@ static int cortex_a_internal_restart(struct target *target)
        if (retval != ERROR_OK)
                return retval;
 
-       long long then = timeval_ms();
+       int64_t then = timeval_ms();
        for (;; ) {
                retval = mem_ap_read_atomic_u32(armv7a->debug_ap,
                                armv7a->debug_base + CPUDBG_DSCR, &dscr);
@@ -1153,7 +1096,8 @@ static int cortex_a_restore_smp(struct target *target, int handle_breakpoints)
        head = target->head;
        while (head != (struct target_list *)NULL) {
                curr = head->target;
-               if ((curr != target) && (curr->state != TARGET_RUNNING)) {
+               if ((curr != target) && (curr->state != TARGET_RUNNING)
+                       && target_was_examined(curr)) {
                        /*  resume current address , not in step mode */
                        retval += cortex_a_internal_restore(curr, 1, &address,
                                        handle_breakpoints, 0);
@@ -1203,7 +1147,7 @@ static int cortex_a_resume(struct target *target, int current,
 static int cortex_a_debug_entry(struct target *target)
 {
        int i;
-       uint32_t regfile[16], cpsr, dscr;
+       uint32_t regfile[16], cpsr, spsr, dscr;
        int retval = ERROR_OK;
        struct working_area *regfile_working_area = NULL;
        struct cortex_a_common *cortex_a = target_to_cortex_a(target);
@@ -1252,6 +1196,7 @@ static int cortex_a_debug_entry(struct target *target)
        if (cortex_a->fast_reg_read)
                target_alloc_working_area(target, 64, &regfile_working_area);
 
+
        /* First load register acessible through core debug port*/
        if (!regfile_working_area)
                retval = arm_dpm_read_current_registers(&armv7a->dpm);
@@ -1296,6 +1241,19 @@ static int cortex_a_debug_entry(struct target *target)
                reg->dirty = reg->valid;
        }
 
+       if (arm->spsr) {
+               /* read Saved PSR */
+               retval = cortex_a_dap_read_coreregister_u32(target, &spsr, 17);
+               /*  store current spsr */
+               if (retval != ERROR_OK)
+                       return retval;
+
+               reg = arm->spsr;
+               buf_set_u32(reg->value, 0, 32, spsr);
+               reg->valid = 1;
+               reg->dirty = 0;
+       }
+
 #if 0
 /* TODO, Move this */
        uint32_t cp15_control_register, cp15_cacr, cp15_nacr;
@@ -1443,7 +1401,7 @@ static int cortex_a_step(struct target *target, int current, uint32_t address,
        if (retval != ERROR_OK)
                return retval;
 
-       long long then = timeval_ms();
+       int64_t then = timeval_ms();
        while (target->state != TARGET_HALTED) {
                retval = cortex_a_poll(target);
                if (retval != ERROR_OK)
@@ -1903,6 +1861,8 @@ static int cortex_a_assert_reset(struct target *target)
 
        /* FIXME when halt is requested, make it work somehow... */
 
+       /* This function can be called in "target not examined" state */
+
        /* Issue some kind of warm reset. */
        if (target_has_event_action(target, TARGET_EVENT_RESET_ASSERT))
                target_handle_event(target, TARGET_EVENT_RESET_ASSERT);
@@ -1910,14 +1870,23 @@ static int cortex_a_assert_reset(struct target *target)
                /* REVISIT handle "pulls" cases, if there's
                 * hardware that needs them to work.
                 */
-               jtag_add_reset(0, 1);
+
+               /*
+                * FIXME: fix reset when transport is SWD. This is a temporary
+                * work-around for release v0.10 that is not intended to stay!
+                */
+               if (transport_is_swd() ||
+                               (target->reset_halt && (jtag_get_reset_config() & RESET_SRST_NO_GATING)))
+                       jtag_add_reset(0, 1);
+
        } else {
                LOG_ERROR("%s: how to reset?", target_name(target));
                return ERROR_FAIL;
        }
 
        /* registers are now invalid */
-       register_cache_invalidate(armv7a->arm.core_cache);
+       if (target_was_examined(target))
+               register_cache_invalidate(armv7a->arm.core_cache);
 
        target->state = TARGET_RESET;
 
@@ -1933,17 +1902,22 @@ static int cortex_a_deassert_reset(struct target *target)
        /* be certain SRST is off */
        jtag_add_reset(0, 0);
 
-       retval = cortex_a_poll(target);
-       if (retval != ERROR_OK)
-               return retval;
+       if (target_was_examined(target)) {
+               retval = cortex_a_poll(target);
+               if (retval != ERROR_OK)
+                       return retval;
+       }
 
        if (target->reset_halt) {
                if (target->state != TARGET_HALTED) {
                        LOG_WARNING("%s: ran after reset and before halt ...",
                                target_name(target));
-                       retval = target_halt(target);
-                       if (retval != ERROR_OK)
-                               return retval;
+                       if (target_was_examined(target)) {
+                               retval = target_halt(target);
+                               if (retval != ERROR_OK)
+                                       return retval;
+                       } else
+                               target->state = TARGET_UNKNOWN;
                }
        }
 
@@ -1977,7 +1951,7 @@ static int cortex_a_wait_dscr_bits(struct target *target, uint32_t mask,
 {
        /* Waits until the specified bit(s) of DSCR take on a specified value. */
        struct armv7a_common *armv7a = target_to_armv7a(target);
-       long long then = timeval_ms();
+       int64_t then = timeval_ms();
        int retval;
 
        while ((*dscr & mask) != value) {
@@ -2123,13 +2097,13 @@ static int cortex_a_dfsr_to_error_code(uint32_t dfsr)
        }
 }
 
-static int cortex_a_write_apb_ab_memory_slow(struct target *target,
+static int cortex_a_write_cpu_memory_slow(struct target *target,
        uint32_t size, uint32_t count, const uint8_t *buffer, uint32_t *dscr)
 {
        /* Writes count objects of size size from *buffer. Old value of DSCR must
         * be in *dscr; updated to new value. This is slow because it works for
         * non-word-sized objects and (maybe) unaligned accesses. If size == 4 and
-        * the address is aligned, cortex_a_write_apb_ab_memory_fast should be
+        * the address is aligned, cortex_a_write_cpu_memory_fast should be
         * preferred.
         * Preconditions:
         * - Address is in R0.
@@ -2198,7 +2172,7 @@ static int cortex_a_write_apb_ab_memory_slow(struct target *target,
        return ERROR_OK;
 }
 
-static int cortex_a_write_apb_ab_memory_fast(struct target *target,
+static int cortex_a_write_cpu_memory_fast(struct target *target,
        uint32_t count, const uint8_t *buffer, uint32_t *dscr)
 {
        /* Writes count objects of size 4 from *buffer. Old value of DSCR must be
@@ -2227,17 +2201,17 @@ static int cortex_a_write_apb_ab_memory_fast(struct target *target,
                        4, count, armv7a->debug_base + CPUDBG_DTRRX);
 }
 
-static int cortex_a_write_apb_ab_memory(struct target *target,
+static int cortex_a_write_cpu_memory(struct target *target,
        uint32_t address, uint32_t size,
        uint32_t count, const uint8_t *buffer)
 {
-       /* Write memory through APB-AP. */
+       /* Write memory through the CPU. */
        int retval, final_retval;
        struct armv7a_common *armv7a = target_to_armv7a(target);
        struct arm *arm = &armv7a->arm;
        uint32_t dscr, orig_dfar, orig_dfsr, fault_dscr, fault_dfar, fault_dfsr;
 
-       LOG_DEBUG("Writing APB-AP memory address 0x%" PRIx32 " size %"  PRIu32 " count %"  PRIu32,
+       LOG_DEBUG("Writing CPU memory address 0x%" PRIx32 " size %"  PRIu32 " count %"  PRIu32,
                          address, size, count);
        if (target->state != TARGET_HALTED) {
                LOG_WARNING("target not halted");
@@ -2283,10 +2257,10 @@ static int cortex_a_write_apb_ab_memory(struct target *target,
 
        if (size == 4 && (address % 4) == 0) {
                /* We are doing a word-aligned transfer, so use fast mode. */
-               retval = cortex_a_write_apb_ab_memory_fast(target, count, buffer, &dscr);
+               retval = cortex_a_write_cpu_memory_fast(target, count, buffer, &dscr);
        } else {
                /* Use slow path. */
-               retval = cortex_a_write_apb_ab_memory_slow(target, size, count, buffer, &dscr);
+               retval = cortex_a_write_cpu_memory_slow(target, size, count, buffer, &dscr);
        }
 
 out:
@@ -2305,7 +2279,7 @@ out:
        /* Wait until DTRRX is empty (according to ARMv7-A/-R architecture manual
         * section C8.4.3, checking InstrCmpl_l is not sufficient; one must also
         * check RXfull_l). Most of the time this will be free because RXfull_l
-        * will be cleared immediately and cached in dscr. However, dont do this
+        * will be cleared immediately and cached in dscr. However, don't do this
         * if there is fault, because then the instruction might not have completed
         * successfully. */
        if (!(dscr & DSCR_STICKY_ABORT_PRECISE)) {
@@ -2366,13 +2340,13 @@ out:
        return final_retval;
 }
 
-static int cortex_a_read_apb_ab_memory_slow(struct target *target,
+static int cortex_a_read_cpu_memory_slow(struct target *target,
        uint32_t size, uint32_t count, uint8_t *buffer, uint32_t *dscr)
 {
        /* Reads count objects of size size into *buffer. Old value of DSCR must be
         * in *dscr; updated to new value. This is slow because it works for
         * non-word-sized objects and (maybe) unaligned accesses. If size == 4 and
-        * the address is aligned, cortex_a_read_apb_ab_memory_fast should be
+        * the address is aligned, cortex_a_read_cpu_memory_fast should be
         * preferred.
         * Preconditions:
         * - Address is in R0.
@@ -2442,7 +2416,7 @@ static int cortex_a_read_apb_ab_memory_slow(struct target *target,
        return ERROR_OK;
 }
 
-static int cortex_a_read_apb_ab_memory_fast(struct target *target,
+static int cortex_a_read_cpu_memory_fast(struct target *target,
        uint32_t count, uint8_t *buffer, uint32_t *dscr)
 {
        /* Reads count objects of size 4 into *buffer. Old value of DSCR must be in
@@ -2529,17 +2503,17 @@ static int cortex_a_read_apb_ab_memory_fast(struct target *target,
        return ERROR_OK;
 }
 
-static int cortex_a_read_apb_ab_memory(struct target *target,
+static int cortex_a_read_cpu_memory(struct target *target,
        uint32_t address, uint32_t size,
        uint32_t count, uint8_t *buffer)
 {
-       /* Read memory through APB-AP. */
+       /* Read memory through the CPU. */
        int retval, final_retval;
        struct armv7a_common *armv7a = target_to_armv7a(target);
        struct arm *arm = &armv7a->arm;
        uint32_t dscr, orig_dfar, orig_dfsr, fault_dscr, fault_dfar, fault_dfsr;
 
-       LOG_DEBUG("Reading APB-AP memory address 0x%" PRIx32 " size %"  PRIu32 " count %"  PRIu32,
+       LOG_DEBUG("Reading CPU memory address 0x%" PRIx32 " size %"  PRIu32 " count %"  PRIu32,
                          address, size, count);
        if (target->state != TARGET_HALTED) {
                LOG_WARNING("target not halted");
@@ -2585,10 +2559,10 @@ static int cortex_a_read_apb_ab_memory(struct target *target,
 
        if (size == 4 && (address % 4) == 0) {
                /* We are doing a word-aligned transfer, so use fast mode. */
-               retval = cortex_a_read_apb_ab_memory_fast(target, count, buffer, &dscr);
+               retval = cortex_a_read_cpu_memory_fast(target, count, buffer, &dscr);
        } else {
                /* Use slow path. */
-               retval = cortex_a_read_apb_ab_memory_slow(target, size, count, buffer, &dscr);
+               retval = cortex_a_read_cpu_memory_slow(target, size, count, buffer, &dscr);
        }
 
 out:
@@ -2660,7 +2634,7 @@ out:
 /*
  * Cortex-A Memory access
  *
- * This is same Cortex M3 but we must also use the correct
+ * This is same Cortex-M3 but we must also use the correct
  * ap number for every access.
  */
 
@@ -2668,17 +2642,25 @@ static int cortex_a_read_phys_memory(struct target *target,
        uint32_t address, uint32_t size,
        uint32_t count, uint8_t *buffer)
 {
-       int retval = ERROR_COMMAND_SYNTAX_ERROR;
+       struct armv7a_common *armv7a = target_to_armv7a(target);
+       struct adiv5_dap *swjdp = armv7a->arm.dap;
+       uint8_t apsel = swjdp->apsel;
+       int retval;
+
+       if (!count || !buffer)
+               return ERROR_COMMAND_SYNTAX_ERROR;
 
        LOG_DEBUG("Reading memory at real address 0x%" PRIx32 "; size %" PRId32 "; count %" PRId32,
                address, size, count);
 
-       if (count && buffer) {
-               /* read memory through APB-AP */
-               cortex_a_prep_memaccess(target, 1);
-               retval = cortex_a_read_apb_ab_memory(target, address, size, count, buffer);
-               cortex_a_post_memaccess(target, 1);
-       }
+       if (armv7a->memory_ap_available && (apsel == armv7a->memory_ap->ap_num))
+               return mem_ap_read_buf(armv7a->memory_ap, buffer, size, count, address);
+
+       /* read memory through the CPU */
+       cortex_a_prep_memaccess(target, 1);
+       retval = cortex_a_read_cpu_memory(target, address, size, count, buffer);
+       cortex_a_post_memaccess(target, 1);
+
        return retval;
 }
 
@@ -2692,7 +2674,7 @@ static int cortex_a_read_memory(struct target *target, uint32_t address,
                size, count);
 
        cortex_a_prep_memaccess(target, 0);
-       retval = cortex_a_read_apb_ab_memory(target, address, size, count, buffer);
+       retval = cortex_a_read_cpu_memory(target, address, size, count, buffer);
        cortex_a_post_memaccess(target, 0);
 
        return retval;
@@ -2745,17 +2727,24 @@ static int cortex_a_write_phys_memory(struct target *target,
        uint32_t address, uint32_t size,
        uint32_t count, const uint8_t *buffer)
 {
-       int retval = ERROR_COMMAND_SYNTAX_ERROR;
+       struct armv7a_common *armv7a = target_to_armv7a(target);
+       struct adiv5_dap *swjdp = armv7a->arm.dap;
+       uint8_t apsel = swjdp->apsel;
+       int retval;
+
+       if (!count || !buffer)
+               return ERROR_COMMAND_SYNTAX_ERROR;
 
        LOG_DEBUG("Writing memory to real address 0x%" PRIx32 "; size %" PRId32 "; count %" PRId32, address,
                size, count);
 
-       if (count && buffer) {
-               /* write memory through APB-AP */
-               cortex_a_prep_memaccess(target, 1);
-               retval = cortex_a_write_apb_ab_memory(target, address, size, count, buffer);
-               cortex_a_post_memaccess(target, 1);
-       }
+       if (armv7a->memory_ap_available && (apsel == armv7a->memory_ap->ap_num))
+               return mem_ap_write_buf(armv7a->memory_ap, buffer, size, count, address);
+
+       /* write memory through the CPU */
+       cortex_a_prep_memaccess(target, 1);
+       retval = cortex_a_write_cpu_memory(target, address, size, count, buffer);
+       cortex_a_post_memaccess(target, 1);
 
        return retval;
 }
@@ -2773,7 +2762,7 @@ static int cortex_a_write_memory(struct target *target, uint32_t address,
        armv7a_cache_auto_flush_on_write(target, address, size * count);
 
        cortex_a_prep_memaccess(target, 0);
-       retval = cortex_a_write_apb_ab_memory(target, address, size, count, buffer);
+       retval = cortex_a_write_cpu_memory(target, address, size, count, buffer);
        cortex_a_post_memaccess(target, 0);
        return retval;
 }
@@ -2908,6 +2897,7 @@ static int cortex_a_handle_target_request(void *priv)
                                armv7a->debug_base + CPUDBG_DSCR, &dscr);
 
                /* check if we have data */
+               int64_t then = timeval_ms();
                while ((dscr & DSCR_DTR_TX_FULL) && (retval == ERROR_OK)) {
                        retval = mem_ap_read_atomic_u32(armv7a->debug_ap,
                                        armv7a->debug_base + CPUDBG_DTRTX, &request);
@@ -2916,6 +2906,10 @@ static int cortex_a_handle_target_request(void *priv)
                                retval = mem_ap_read_atomic_u32(armv7a->debug_ap,
                                                armv7a->debug_base + CPUDBG_DSCR, &dscr);
                        }
+                       if (timeval_ms() > then + 1000) {
+                               LOG_ERROR("Timeout waiting for dtr tx full");
+                               return ERROR_FAIL;
+                       }
                }
        }
 
@@ -2931,9 +2925,10 @@ static int cortex_a_examine_first(struct target *target)
        struct cortex_a_common *cortex_a = target_to_cortex_a(target);
        struct armv7a_common *armv7a = &cortex_a->armv7a_common;
        struct adiv5_dap *swjdp = armv7a->arm.dap;
+
        int i;
        int retval = ERROR_OK;
-       uint32_t didr, ctypr, ttypr, cpuid, dbg_osreg;
+       uint32_t didr, cpuid, dbg_osreg;
 
        retval = dap_dp_init(swjdp);
        if (retval != ERROR_OK) {
@@ -2941,7 +2936,7 @@ static int cortex_a_examine_first(struct target *target)
                return retval;
        }
 
-       /* Search for the APB-AB - it is needed for access to debug registers */
+       /* Search for the APB-AP - it is needed for access to debug registers */
        retval = dap_find_ap(swjdp, AP_TYPE_APB_AP, &armv7a->debug_ap);
        if (retval != ERROR_OK) {
                LOG_ERROR("Could not find APB-AP for debug access");
@@ -2965,11 +2960,10 @@ static int cortex_a_examine_first(struct target *target)
                retval = mem_ap_init(armv7a->memory_ap);
                if (retval == ERROR_OK)
                        armv7a->memory_ap_available = true;
-               else
-                       LOG_WARNING("Could not initialize AHB-AP for memory access - using APB-AP");
-       } else {
-               /* AHB-AP not found - use APB-AP */
-               LOG_DEBUG("Could not find AHB-AP - using APB-AP for memory access");
+       }
+       if (retval != ERROR_OK) {
+               /* AHB-AP not found or unavailable - use the CPU */
+               LOG_DEBUG("No AHB-AP available for memory access");
        }
 
        if (!target->dbgbase_set) {
@@ -2996,79 +2990,69 @@ static int cortex_a_examine_first(struct target *target)
                armv7a->debug_base = target->dbgbase;
 
        retval = mem_ap_read_atomic_u32(armv7a->debug_ap,
-                       armv7a->debug_base + CPUDBG_CPUID, &cpuid);
-       if (retval != ERROR_OK)
-               return retval;
-
-       retval = mem_ap_read_atomic_u32(armv7a->debug_ap,
-                       armv7a->debug_base + CPUDBG_CPUID, &cpuid);
-       if (retval != ERROR_OK) {
-               LOG_DEBUG("Examine %s failed", "CPUID");
-               return retval;
-       }
-
-       retval = mem_ap_read_atomic_u32(armv7a->debug_ap,
-                       armv7a->debug_base + CPUDBG_CTYPR, &ctypr);
-       if (retval != ERROR_OK) {
-               LOG_DEBUG("Examine %s failed", "CTYPR");
-               return retval;
-       }
-
-       retval = mem_ap_read_atomic_u32(armv7a->debug_ap,
-                       armv7a->debug_base + CPUDBG_TTYPR, &ttypr);
+                       armv7a->debug_base + CPUDBG_DIDR, &didr);
        if (retval != ERROR_OK) {
-               LOG_DEBUG("Examine %s failed", "TTYPR");
+               LOG_DEBUG("Examine %s failed", "DIDR");
                return retval;
        }
 
        retval = mem_ap_read_atomic_u32(armv7a->debug_ap,
-                       armv7a->debug_base + CPUDBG_DIDR, &didr);
+                       armv7a->debug_base + CPUDBG_CPUID, &cpuid);
        if (retval != ERROR_OK) {
-               LOG_DEBUG("Examine %s failed", "DIDR");
+               LOG_DEBUG("Examine %s failed", "CPUID");
                return retval;
        }
 
-       LOG_DEBUG("cpuid = 0x%08" PRIx32, cpuid);
-       LOG_DEBUG("ctypr = 0x%08" PRIx32, ctypr);
-       LOG_DEBUG("ttypr = 0x%08" PRIx32, ttypr);
        LOG_DEBUG("didr = 0x%08" PRIx32, didr);
+       LOG_DEBUG("cpuid = 0x%08" PRIx32, cpuid);
 
-       cortex_a->cpuid = cpuid;
-       cortex_a->ctypr = ctypr;
-       cortex_a->ttypr = ttypr;
        cortex_a->didr = didr;
+       cortex_a->cpuid = cpuid;
 
-       /* Unlocking the debug registers */
-       if ((cpuid & CORTEX_A_MIDR_PARTNUM_MASK) >> CORTEX_A_MIDR_PARTNUM_SHIFT ==
-               CORTEX_A15_PARTNUM) {
-
-               retval = mem_ap_write_atomic_u32(armv7a->debug_ap,
-                                                    armv7a->debug_base + CPUDBG_OSLAR,
-                                                    0);
-
-               if (retval != ERROR_OK)
-                       return retval;
+       retval = mem_ap_read_atomic_u32(armv7a->debug_ap,
+                                   armv7a->debug_base + CPUDBG_PRSR, &dbg_osreg);
+       if (retval != ERROR_OK)
+               return retval;
+       LOG_DEBUG("target->coreid %" PRId32 " DBGPRSR  0x%" PRIx32, target->coreid, dbg_osreg);
 
+       if ((dbg_osreg & PRSR_POWERUP_STATUS) == 0) {
+               LOG_ERROR("target->coreid %" PRId32 " powered down!", target->coreid);
+               target->state = TARGET_UNKNOWN; /* TARGET_NO_POWER? */
+               return ERROR_TARGET_INIT_FAILED;
        }
-       /* Unlocking the debug registers */
-       if ((cpuid & CORTEX_A_MIDR_PARTNUM_MASK) >> CORTEX_A_MIDR_PARTNUM_SHIFT ==
-               CORTEX_A7_PARTNUM) {
 
-               retval = mem_ap_write_atomic_u32(armv7a->debug_ap,
-                                                    armv7a->debug_base + CPUDBG_OSLAR,
-                                                    0);
+       if (dbg_osreg & PRSR_STICKY_RESET_STATUS)
+               LOG_DEBUG("target->coreid %" PRId32 " was reset!", target->coreid);
 
-               if (retval != ERROR_OK)
-                       return retval;
-
-       }
+       /* Read DBGOSLSR and check if OSLK is implemented */
        retval = mem_ap_read_atomic_u32(armv7a->debug_ap,
-                                           armv7a->debug_base + CPUDBG_PRSR, &dbg_osreg);
-
+                               armv7a->debug_base + CPUDBG_OSLSR, &dbg_osreg);
        if (retval != ERROR_OK)
                return retval;
+       LOG_DEBUG("target->coreid %" PRId32 " DBGOSLSR 0x%" PRIx32, target->coreid, dbg_osreg);
 
-       LOG_DEBUG("target->coreid %" PRId32 " DBGPRSR  0x%" PRIx32, target->coreid, dbg_osreg);
+       /* check if OS Lock is implemented */
+       if ((dbg_osreg & OSLSR_OSLM) == OSLSR_OSLM0 || (dbg_osreg & OSLSR_OSLM) == OSLSR_OSLM1) {
+               /* check if OS Lock is set */
+               if (dbg_osreg & OSLSR_OSLK) {
+                       LOG_DEBUG("target->coreid %" PRId32 " OSLock set! Trying to unlock", target->coreid);
+
+                       retval = mem_ap_write_atomic_u32(armv7a->debug_ap,
+                                                       armv7a->debug_base + CPUDBG_OSLAR,
+                                                       0);
+                       if (retval == ERROR_OK)
+                               retval = mem_ap_read_atomic_u32(armv7a->debug_ap,
+                                                       armv7a->debug_base + CPUDBG_OSLSR, &dbg_osreg);
+
+                       /* if we fail to access the register or cannot reset the OSLK bit, bail out */
+                       if (retval != ERROR_OK || (dbg_osreg & OSLSR_OSLK) != 0) {
+                               LOG_ERROR("target->coreid %" PRId32 " OSLock sticky, core not powered?",
+                                               target->coreid);
+                               target->state = TARGET_UNKNOWN; /* TARGET_NO_POWER? */
+                               return ERROR_TARGET_INIT_FAILED;
+                       }
+               }
+       }
 
        armv7a->arm.core_type = ARM_MODE_MON;
 
@@ -3128,6 +3112,7 @@ static int cortex_a_init_target(struct command_context *cmd_ctx,
        struct target *target)
 {
        /* examine_first() does a bunch of this */
+       arm_semihosting_init(target);
        return ERROR_OK;
 }
 
@@ -3331,17 +3316,14 @@ COMMAND_HANDLER(handle_cortex_a_mask_interrupts_command)
        };
        const Jim_Nvp *n;
 
-       if (target->state != TARGET_HALTED) {
-               command_print(CMD_CTX, "target must be stopped for \"%s\" command", CMD_NAME);
-               return ERROR_OK;
-       }
-
        if (CMD_ARGC > 0) {
                n = Jim_Nvp_name2value_simple(nvp_maskisr_modes, CMD_ARGV[0]);
-               if (n->name == NULL)
+               if (n->name == NULL) {
+                       LOG_ERROR("Unknown parameter: %s - should be off or on", CMD_ARGV[0]);
                        return ERROR_COMMAND_SYNTAX_ERROR;
-               cortex_a->isrmasking_mode = n->value;
+               }
 
+               cortex_a->isrmasking_mode = n->value;
        }
 
        n = Jim_Nvp_value2name_simple(nvp_maskisr_modes, cortex_a->isrmasking_mode);
@@ -3413,7 +3395,7 @@ static const struct command_registration cortex_a_exec_command_handlers[] = {
        {
                .name = "maskisr",
                .handler = handle_cortex_a_mask_interrupts_command,
-               .mode = COMMAND_EXEC,
+               .mode = COMMAND_ANY,
                .help = "mask cortex_a interrupts",
                .usage = "['on'|'off']",
        },
@@ -3550,8 +3532,8 @@ struct target_type cortexr4_target = {
        /* REVISIT allow exporting VFP3 registers ... */
        .get_gdb_reg_list = arm_get_gdb_reg_list,
 
-       .read_memory = cortex_a_read_memory,
-       .write_memory = cortex_a_write_memory,
+       .read_memory = cortex_a_read_phys_memory,
+       .write_memory = cortex_a_write_phys_memory,
 
        .checksum_memory = arm_checksum_memory,
        .blank_check_memory = arm_blank_check_memory,