David Brownell <david-b@pacbell.net>:

Clean up treatment of registers in ARMv7-M and Cortex-M3.

 - At the arch level:
    * Just list registers and names; don't impose core-specific
      policy about how they are accessed.
    * Each register has a symbol.
    * Remove the register mode field (irrelevant to debugger)

 - At the core/implementation level:
    * Just map the registers to their relevant access methods;
      don't require the arch level to say how that should work
      (cores other than Cortex-M3 could do it differently).
    * Don't use undefined bits from register 20.
    * Use register IDs that are part of the ARMv7-M interface.

In short, there's now a real distinction between the arch
and core layers.

git-svn-id: svn://svn.berlios.de/openocd/trunk@2554 b42882b7-edfa-0310-969c-e2dbd0fdcd60

diff --git a/src/target/armv7m.c b/src/target/armv7m.c
index 5849443018afb4c75481110bc3dae203db8e85c8..74c1ce43ab55fecbeb9b7fcf22081b70121b5322 100644 (file)
--- a/src/target/armv7m.c
+++ b/src/target/armv7m.c
@@ -36,6 +36,8 @@
 
 #include "armv7m.h"
 
+#define ARRAY_SIZE(x)  ((int)(sizeof(x)/sizeof((x)[0])))
+
 
 #if 0
 #define _DEBUG_INSTRUCTION_EXECUTION_
@@ -46,7 +48,7 @@ char* armv7m_mode_strings[] =
        "Thread", "Thread (User)", "Handler",
 };
 
-char* armv7m_exception_strings[] =
+static char *armv7m_exception_strings[] =
 {
        "", "Reset", "NMI", "HardFault",
        "MemManage", "BusFault", "UsageFault", "RESERVED",
@@ -54,16 +56,6 @@ char* armv7m_exception_strings[] =
        "DebugMonitor", "RESERVED", "PendSV", "SysTick"
 };
 
-char* armv7m_core_reg_list[] =
-{
-       /* Registers accessed through core debug */
-       "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "r12",
-       "sp", "lr", "pc",
-       "xPSR", "msp", "psp",
-       /* Registers accessed through special reg 20 */
-       "primask", "basepri", "faultmask", "control"
-};
-
 uint8_t armv7m_gdb_dummy_fp_value[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
 
 reg_t armv7m_gdb_dummy_fp_reg =
@@ -87,37 +79,47 @@ reg_t armv7m_gdb_dummy_cpsr_reg =
 };
 #endif
 
-armv7m_core_reg_t armv7m_core_reg_list_arch_info[] =
-{
-       /*  CORE_GP are accesible using the core debug registers */
-       {0, ARMV7M_REGISTER_CORE_GP, ARMV7M_MODE_ANY, NULL, NULL},
-       {1, ARMV7M_REGISTER_CORE_GP, ARMV7M_MODE_ANY, NULL, NULL},
-       {2, ARMV7M_REGISTER_CORE_GP, ARMV7M_MODE_ANY, NULL, NULL},
-       {3, ARMV7M_REGISTER_CORE_GP, ARMV7M_MODE_ANY, NULL, NULL},
-       {4, ARMV7M_REGISTER_CORE_GP, ARMV7M_MODE_ANY, NULL, NULL},
-       {5, ARMV7M_REGISTER_CORE_GP, ARMV7M_MODE_ANY, NULL, NULL},
-       {6, ARMV7M_REGISTER_CORE_GP, ARMV7M_MODE_ANY, NULL, NULL},
-       {7, ARMV7M_REGISTER_CORE_GP, ARMV7M_MODE_ANY, NULL, NULL},
-       {8, ARMV7M_REGISTER_CORE_GP, ARMV7M_MODE_ANY, NULL, NULL},
-       {9, ARMV7M_REGISTER_CORE_GP, ARMV7M_MODE_ANY, NULL, NULL},
-       {10, ARMV7M_REGISTER_CORE_GP, ARMV7M_MODE_ANY, NULL, NULL},
-       {11, ARMV7M_REGISTER_CORE_GP, ARMV7M_MODE_ANY, NULL, NULL},
-       {12, ARMV7M_REGISTER_CORE_GP, ARMV7M_MODE_ANY, NULL, NULL},
-       {13, ARMV7M_REGISTER_CORE_GP, ARMV7M_MODE_ANY, NULL, NULL},
-       {14, ARMV7M_REGISTER_CORE_GP, ARMV7M_MODE_ANY, NULL, NULL},
-       {15, ARMV7M_REGISTER_CORE_GP, ARMV7M_MODE_ANY, NULL, NULL},
-
-       {16, ARMV7M_REGISTER_CORE_GP, ARMV7M_MODE_ANY, NULL, NULL}, /* xPSR */
-       {17, ARMV7M_REGISTER_CORE_GP, ARMV7M_MODE_ANY, NULL, NULL}, /* MSP */
-       {18, ARMV7M_REGISTER_CORE_GP, ARMV7M_MODE_ANY, NULL, NULL}, /* PSP */
-
-       /*  CORE_SP are accesible using coreregister 20 */
-       {19, ARMV7M_REGISTER_CORE_SP, ARMV7M_MODE_ANY, NULL, NULL}, /* PRIMASK */
-       {20, ARMV7M_REGISTER_CORE_SP, ARMV7M_MODE_ANY, NULL, NULL}, /* BASEPRI */
-       {21, ARMV7M_REGISTER_CORE_SP, ARMV7M_MODE_ANY, NULL, NULL}, /* FAULTMASK */
-       {22, ARMV7M_REGISTER_CORE_SP, ARMV7M_MODE_ANY, NULL, NULL}  /* CONTROL */
+/*
+ * These registers are not memory-mapped.  The ARMv7-M profile includes
+ * memory mapped registers too, such as for the NVIC (interrupt controller)
+ * and SysTick (timer) modules; those can mostly be treated as peripherals.
+ */
+static const struct {
+       unsigned id;
+       char *name;
+} armv7m_regs[] = {
+       { ARMV7M_R0, "r0" },
+       { ARMV7M_R1, "r1" },
+       { ARMV7M_R2, "r2" },
+       { ARMV7M_R3, "r3" },
+
+       { ARMV7M_R4, "r4" },
+       { ARMV7M_R5, "r5" },
+       { ARMV7M_R6, "r6" },
+       { ARMV7M_R7, "r7" },
+
+       { ARMV7M_R8, "r8" },
+       { ARMV7M_R9, "r9" },
+       { ARMV7M_R10, "r10" },
+       { ARMV7M_R11, "r11" },
+
+       { ARMV7M_R12, "r12" },
+       { ARMV7M_R13, "sp" },
+       { ARMV7M_R14, "lr" },
+       { ARMV7M_PC, "pc" },
+
+       { ARMV7M_xPSR, "xPSR" },
+       { ARMV7M_MSP, "msp" },
+       { ARMV7M_PSP, "psp" },
+
+       { ARMV7M_PRIMASK, "primask" },
+       { ARMV7M_BASEPRI, "basepri" },
+       { ARMV7M_FAULTMASK, "faultmask" },
+       { ARMV7M_CONTROL, "control" },
 };
 
+#define ARMV7M_NUM_REGS        ARRAY_SIZE(armv7m_regs)
+
 int armv7m_core_reg_arch_type = -1;
 int armv7m_dummy_core_reg_arch_type = -1;
 
@@ -133,7 +135,7 @@ int armv7m_restore_context(target_t *target)
        if (armv7m->pre_restore_context)
                armv7m->pre_restore_context(target);
 
-       for (i = ARMV7NUMCOREREGS-1; i >= 0; i--)
+       for (i = ARMV7M_NUM_REGS - 1; i >= 0; i--)
        {
                if (armv7m->core_cache->reg_list[i].dirty)
                {
@@ -204,7 +206,7 @@ int armv7m_read_core_reg(struct target_s *target, int num)
        /* get pointers to arch-specific information */
        armv7m_common_t *armv7m = target->arch_info;
 
-       if ((num < 0) || (num >= ARMV7NUMCOREREGS))
+       if ((num < 0) || (num >= ARMV7M_NUM_REGS))
                return ERROR_INVALID_ARGUMENTS;
 
        armv7m_core_reg = armv7m->core_cache->reg_list[num].arch_info;
@@ -225,7 +227,7 @@ int armv7m_write_core_reg(struct target_s *target, int num)
        /* get pointers to arch-specific information */
        armv7m_common_t *armv7m = target->arch_info;
 
-       if ((num < 0) || (num >= ARMV7NUMCOREREGS))
+       if ((num < 0) || (num >= ARMV7M_NUM_REGS))
                return ERROR_INVALID_ARGUMENTS;
 
        reg_value = buf_get_u32(armv7m->core_cache->reg_list[num].value, 0, 32);
@@ -268,6 +270,13 @@ int armv7m_get_gdb_reg_list(target_t *target, reg_t **reg_list[], int *reg_list_
        *reg_list_size = 26;
        *reg_list = malloc(sizeof(reg_t*) * (*reg_list_size));
 
+       /*
+        * GDB register packet format for ARM:
+        *  - the first 16 registers are r0..r15
+        *  - (obsolete) 8 FPA registers
+        *  - (obsolete) FPA status
+        *  - CPSR
+        */
        for (i = 0; i < 16; i++)
        {
                (*reg_list)[i] = &armv7m->core_cache->reg_list[i];
@@ -337,7 +346,7 @@ int armv7m_run_algorithm(struct target_s *target, int num_mem_params, mem_param_
        enum armv7m_mode core_mode = armv7m->core_mode;
        int retval = ERROR_OK;
        int i;
-       uint32_t context[ARMV7NUMCOREREGS];
+       uint32_t context[ARMV7M_NUM_REGS];
 
        if (armv7m_algorithm_info->common_magic != ARMV7M_COMMON_MAGIC)
        {
@@ -353,7 +362,7 @@ int armv7m_run_algorithm(struct target_s *target, int num_mem_params, mem_param_
 
        /* refresh core register cache */
        /* Not needed if core register cache is always consistent with target process state */
-       for (i = 0; i < ARMV7NUMCOREREGS; i++)
+       for (i = 0; i < ARMV7M_NUM_REGS; i++)
        {
                if (!armv7m->core_cache->reg_list[i].valid)
                        armv7m->read_core_reg(target, i);
@@ -390,7 +399,8 @@ int armv7m_run_algorithm(struct target_s *target, int num_mem_params, mem_param_
        if (armv7m_algorithm_info->core_mode != ARMV7M_MODE_ANY)
        {
                LOG_DEBUG("setting core_mode: 0x%2.2x", armv7m_algorithm_info->core_mode);
-               buf_set_u32(armv7m->core_cache->reg_list[ARMV7M_CONTROL].value, 0, 1, armv7m_algorithm_info->core_mode);
+               buf_set_u32(armv7m->core_cache->reg_list[ARMV7M_CONTROL].value,
+                               0, 1, armv7m_algorithm_info->core_mode);
                armv7m->core_cache->reg_list[ARMV7M_CONTROL].dirty = 1;
                armv7m->core_cache->reg_list[ARMV7M_CONTROL].valid = 1;
        }
@@ -444,14 +454,16 @@ int armv7m_run_algorithm(struct target_s *target, int num_mem_params, mem_param_
                }
        }
 
-       for (i = ARMV7NUMCOREREGS-1; i >= 0; i--)
+       for (i = ARMV7M_NUM_REGS; i >= 0; i--)
        {
                uint32_t regvalue;
                regvalue = buf_get_u32(armv7m->core_cache->reg_list[i].value, 0, 32);
                if (regvalue != context[i])
                {
-                       LOG_DEBUG("restoring register %s with value 0x%8.8" PRIx32 "", armv7m->core_cache->reg_list[i].name, context[i]);
-                       buf_set_u32(armv7m->core_cache->reg_list[i].value, 0, 32, context[i]);
+                       LOG_DEBUG("restoring register %s with value 0x%8.8" PRIx32,
+                               armv7m->core_cache->reg_list[i].name, context[i]);
+                       buf_set_u32(armv7m->core_cache->reg_list[i].value,
+                                       0, 32, context[i]);
                        armv7m->core_cache->reg_list[i].valid = 1;
                        armv7m->core_cache->reg_list[i].dirty = 1;
                }
@@ -467,12 +479,13 @@ int armv7m_arch_state(struct target_s *target)
        /* get pointers to arch-specific information */
        armv7m_common_t *armv7m = target->arch_info;
 
-       LOG_USER("target halted due to %s, current mode: %s %s\nxPSR: 0x%8.8" PRIx32 " pc: 0x%8.8" PRIx32 "",
+       LOG_USER("target halted due to %s, current mode: %s %s\n"
+               "xPSR: 0x%8.8" PRIx32 " pc: 0x%8.8" PRIx32,
                 Jim_Nvp_value2name_simple(nvp_target_debug_reason,target->debug_reason)->name,
                armv7m_mode_strings[armv7m->core_mode],
                armv7m_exception_string(armv7m->exception_number),
                buf_get_u32(armv7m->core_cache->reg_list[ARMV7M_xPSR].value, 0, 32),
-               buf_get_u32(armv7m->core_cache->reg_list[15].value, 0, 32));
+               buf_get_u32(armv7m->core_cache->reg_list[ARMV7M_PC].value, 0, 32));
 
        return ERROR_OK;
 }
@@ -482,11 +495,11 @@ reg_cache_t *armv7m_build_reg_cache(target_t *target)
        /* get pointers to arch-specific information */
        armv7m_common_t *armv7m = target->arch_info;
 
-       int num_regs = ARMV7NUMCOREREGS;
+       int num_regs = ARMV7M_NUM_REGS;
        reg_cache_t **cache_p = register_get_last_cache_p(&target->reg_cache);
        reg_cache_t *cache = malloc(sizeof(reg_cache_t));
-       reg_t *reg_list = malloc(sizeof(reg_t) * num_regs);
-       armv7m_core_reg_t *arch_info = malloc(sizeof(armv7m_core_reg_t) * num_regs);
+       reg_t *reg_list = calloc(num_regs, sizeof(reg_t));
+       armv7m_core_reg_t *arch_info = calloc(num_regs, sizeof(armv7m_core_reg_t));
        int i;
 
        if (armv7m_core_reg_arch_type == -1)
@@ -510,10 +523,10 @@ reg_cache_t *armv7m_build_reg_cache(target_t *target)
 
        for (i = 0; i < num_regs; i++)
        {
-               arch_info[i] = armv7m_core_reg_list_arch_info[i];
+               arch_info[i].num = armv7m_regs[i].id;
                arch_info[i].target = target;
                arch_info[i].armv7m_common = armv7m;
-               reg_list[i].name = armv7m_core_reg_list[i];
+               reg_list[i].name = armv7m_regs[i].name;
                reg_list[i].size = 32;
                reg_list[i].value = calloc(1, 4);
                reg_list[i].dirty = 0;

diff --git a/src/target/armv7m.h b/src/target/armv7m.h
index ec90b7150d0d8a16ab31724970156fb6922f5912..f3a74221ce9d3ea06bba73b5a680efbaa218b2ef 100644 (file)
--- a/src/target/armv7m.h
+++ b/src/target/armv7m.h
@@ -50,22 +50,43 @@ enum armv7m_regtype
        ARMV7M_REGISTER_MEMMAP
 };
 
-extern char* armv7m_exception_strings[];
-
 extern char *armv7m_exception_string(int number);
 
 /* offsets into armv7m core register cache */
 enum
 {
+       /* for convenience, the first set of indices match
+        * the Cortex-M3 DCRSR selectors
+        */
+       ARMV7M_R0,
+       ARMV7M_R1,
+       ARMV7M_R2,
+       ARMV7M_R3,
+
+       ARMV7M_R4,
+       ARMV7M_R5,
+       ARMV7M_R6,
+       ARMV7M_R7,
+
+       ARMV7M_R8,
+       ARMV7M_R9,
+       ARMV7M_R10,
+       ARMV7M_R11,
+
+       ARMV7M_R12,
+       ARMV7M_R13,
+       ARMV7M_R14,
        ARMV7M_PC = 15,
+
        ARMV7M_xPSR = 16,
        ARMV7M_MSP,
        ARMV7M_PSP,
+
+       /* this next set of indices is arbitrary */
        ARMV7M_PRIMASK,
        ARMV7M_BASEPRI,
        ARMV7M_FAULTMASK,
        ARMV7M_CONTROL,
-       ARMV7NUMCOREREGS
 };
 
 #define ARMV7M_COMMON_MAGIC 0x2A452A45
@@ -107,7 +128,6 @@ typedef struct armv7m_core_reg_s
 {
        uint32_t num;
        enum armv7m_regtype type;
-       enum armv7m_mode mode;
        target_t *target;
        armv7m_common_t *armv7m_common;
 } armv7m_core_reg_t;

diff --git a/src/target/cortex_m3.c b/src/target/cortex_m3.c
index 94d420468e488971c4d5b0c3c1cb13cdf148d120..8875dddc685ee0edee97005c0f291dd51564d121 100644 (file)
--- a/src/target/cortex_m3.c
+++ b/src/target/cortex_m3.c
@@ -395,7 +395,9 @@ int cortex_m3_debug_entry(target_t *target)
 
        /* Examine target state and mode */
        /* First load register acessible through core debug port*/
-       for (i = 0; i < ARMV7M_PRIMASK; i++)
+       int num_regs = armv7m->core_cache->num_regs;
+
+       for (i = 0; i < num_regs; i++)
        {
                if (!armv7m->core_cache->reg_list[i].valid)
                        armv7m->read_core_reg(target, i);
@@ -418,13 +420,6 @@ int cortex_m3_debug_entry(target_t *target)
                cortex_m3_store_core_reg_u32(target, ARMV7M_REGISTER_CORE_GP, 16, xPSR &~ 0xff);
        }
 
-       /* Now we can load SP core registers */
-       for (i = ARMV7M_PRIMASK; i < ARMV7NUMCOREREGS; i++)
-       {
-               if (!armv7m->core_cache->reg_list[i].valid)
-                       armv7m->read_core_reg(target, i);
-       }
-
        /* Are we in an exception handler */
        if (xPSR & 0x1FF)
        {
@@ -1253,8 +1248,12 @@ int cortex_m3_load_core_reg_u32(struct target_s *target, enum armv7m_regtype typ
        armv7m_common_t *armv7m = target->arch_info;
        swjdp_common_t *swjdp = &armv7m->swjdp_info;
 
-       if ((type == ARMV7M_REGISTER_CORE_GP) && (num <= ARMV7M_PSP))
-       {
+       /* NOTE:  we "know" here that the register identifiers used
+        * in the v7m header match the Cortex-M3 Debug Core Register
+        * Selector values for R0..R15, xPSR, MSP, and PSP.
+        */
+       switch (num) {
+       case 0 ... 18:
                /* read a normal core register */
                retval = cortexm3_dap_read_coreregister_u32(swjdp, value, num);
 
@@ -1264,35 +1263,41 @@ int cortex_m3_load_core_reg_u32(struct target_s *target, enum armv7m_regtype typ
                        return ERROR_JTAG_DEVICE_ERROR;
                }
                LOG_DEBUG("load from core reg %i  value 0x%" PRIx32 "",(int)num,*value);
-       }
-       else if (type == ARMV7M_REGISTER_CORE_SP) /* Special purpose core register */
-       {
-               /* read other registers */
+               break;
+
+       case ARMV7M_PRIMASK:
+       case ARMV7M_BASEPRI:
+       case ARMV7M_FAULTMASK:
+       case ARMV7M_CONTROL:
+               /* Cortex-M3 packages these four registers as bitfields
+                * in one Debug Core register.  So say r0 and r2 docs;
+                * it was removed from r1 docs, but still works.
+                */
                cortexm3_dap_read_coreregister_u32(swjdp, value, 20);
 
                switch (num)
                {
-                       case 19:
-                               *value = buf_get_u32((uint8_t*)value, 0, 8);
+                       case ARMV7M_PRIMASK:
+                               *value = buf_get_u32((uint8_t*)value, 0, 1);
                                break;
 
-                       case 20:
+                       case ARMV7M_BASEPRI:
                                *value = buf_get_u32((uint8_t*)value, 8, 8);
                                break;
 
-                       case 21:
-                               *value = buf_get_u32((uint8_t*)value, 16, 8);
+                       case ARMV7M_FAULTMASK:
+                               *value = buf_get_u32((uint8_t*)value, 16, 1);
                                break;
 
-                       case 22:
-                               *value = buf_get_u32((uint8_t*)value, 24, 8);
+                       case ARMV7M_CONTROL:
+                               *value = buf_get_u32((uint8_t*)value, 24, 2);
                                break;
                }
 
                LOG_DEBUG("load from special reg %i value 0x%" PRIx32 "", (int)num, *value);
-       }
-       else
-       {
+               break;
+
+       default:
                return ERROR_INVALID_ARGUMENTS;
        }
 
@@ -1313,14 +1318,19 @@ int cortex_m3_store_core_reg_u32(struct target_s *target, enum armv7m_regtype ty
         * in "thumb" mode, or an INVSTATE exception will occur. This is a
         * hack to deal with the fact that gdb will sometimes "forge"
         * return addresses, and doesn't set the LSB correctly (i.e., when
-        * printing expressions containing function calls, it sets LR = 0.) */
-
-       if (num == 14)
+        * printing expressions containing function calls, it sets LR = 0.)
+        * Valid exception return codes have bit 0 set too.
+        */
+       if (num == ARMV7M_R14)
                value |= 0x01;
 #endif
 
-       if ((type == ARMV7M_REGISTER_CORE_GP) && (num <= ARMV7M_PSP))
-       {
+       /* NOTE:  we "know" here that the register identifiers used
+        * in the v7m header match the Cortex-M3 Debug Core Register
+        * Selector values for R0..R15, xPSR, MSP, and PSP.
+        */
+       switch (num) {
+       case 0 ... 18:
                retval = cortexm3_dap_write_coreregister_u32(swjdp, value, num);
                if (retval != ERROR_OK)
                {
@@ -1329,38 +1339,43 @@ int cortex_m3_store_core_reg_u32(struct target_s *target, enum armv7m_regtype ty
                        return ERROR_JTAG_DEVICE_ERROR;
                }
                LOG_DEBUG("write core reg %i value 0x%" PRIx32 "", (int)num, value);
-       }
-       else if (type == ARMV7M_REGISTER_CORE_SP) /* Special purpose core register */
-       {
-               /* write other registers */
-
+               break;
+
+       case ARMV7M_PRIMASK:
+       case ARMV7M_BASEPRI:
+       case ARMV7M_FAULTMASK:
+       case ARMV7M_CONTROL:
+               /* Cortex-M3 packages these four registers as bitfields
+                * in one Debug Core register.  So say r0 and r2 docs;
+                * it was removed from r1 docs, but still works.
+                */
                cortexm3_dap_read_coreregister_u32(swjdp, &reg, 20);
 
                switch (num)
                {
-                       case 19:
-                               buf_set_u32((uint8_t*)&reg, 0, 8, value);
+                       case ARMV7M_PRIMASK:
+                               buf_set_u32((uint8_t*)&reg, 0, 1, value);
                                break;
 
-                       case 20:
+                       case ARMV7M_BASEPRI:
                                buf_set_u32((uint8_t*)&reg, 8, 8, value);
                                break;
 
-                       case 21:
-                               buf_set_u32((uint8_t*)&reg, 16, 8, value);
+                       case ARMV7M_FAULTMASK:
+                               buf_set_u32((uint8_t*)&reg, 16, 1, value);
                                break;
 
-                       case 22:
-                               buf_set_u32((uint8_t*)&reg, 24, 8, value);
+                       case ARMV7M_CONTROL:
+                               buf_set_u32((uint8_t*)&reg, 24, 2, value);
                                break;
                }
 
                cortexm3_dap_write_coreregister_u32(swjdp, reg, 20);
 
                LOG_DEBUG("write special reg %i value 0x%" PRIx32 " ", (int)num, value);
-       }
-       else
-       {
+               break;
+
+       default:
                return ERROR_INVALID_ARGUMENTS;
        }