When setting up an ETM, cache its ETM_CONFIG register. Then

only expose the registers which are actually present.  They
could be missing for two basic reasons:

 - This version might not support them at all; e.g. ETMv1.1
   doesn't have some control/status registers.  (My sample of
   ARM9 boards shows all with ETMv1.3 support, FWIW.)

 - The configuration on this chip may not populate as many
   registers as possible; e.g. only two data value comparators
   instead of eight.

Includes a bugfix in the "etm info" command:  only one of the
two registers is missing on older silicon, so show the first
one before bailing.

Update ETM usage docs to explain that those registers need to be
written to configure what is traced, and that some ETM configs
are not yet handled.  Also, give some examples of the kinds of
constrained trace which could be arranged.

git-svn-id: svn://svn.berlios.de/openocd/trunk@2752 b42882b7-edfa-0310-969c-e2dbd0fdcd60

diff --git a/doc/openocd.texi b/doc/openocd.texi
index 893d738c91e9b363daad216f8036261141e8528a..35c1b0d314813dc24f1a795c86c9d4315045e09c 100644 (file)
--- a/doc/openocd.texi
+++ b/doc/openocd.texi
@@ -4807,6 +4807,10 @@ analyse it in conjunction with the source code.
 It's unclear how much of a common interface is shared
 with the current XScale trace support, or should be
 shared with eventual Nexus-style trace module support.
+At this writing (September 2009) only ARM7 and ARM9 support
+for ETM modules is available.  The code should be able to
+work with some newer cores; but not all of them support
+this original style of JTAG access.
 @end quotation
 
 @subsection ETM Configuration
@@ -4823,8 +4827,10 @@ or @option{demultiplexted}.
 The @var{clocking} must be @option{half} or @option{full}.
 
 @quotation Note
-You can see the ETM registers using the @command{reg} command, although
-not all of those possible registers are present in every ETM.
+You can see the ETM registers using the @command{reg} command.
+Not all possible registers are present in every ETM.
+Most of the registers are write-only, and are used to configure
+what CPU activities are traced.
 @end quotation
 @end deffn
 
@@ -4867,6 +4873,36 @@ After setting up the ETM, you can use it to collect data.
 That data can be exported to files for later analysis.
 It can also be parsed with OpenOCD, for basic sanity checking.
 
+To configure what is being traced, you will need to write
+various trace registers using @command{reg ETM_*} commands.
+For the definitions of these registers, read ARM publication
+@emph{IHI 0014, ``Embedded Trace Macrocell, Architecture Specification''}.
+Be aware that most of the relevant registers are write-only,
+and that ETM resources are limited.  There are only a handful
+of address comparators, data comparators, counters, and so on.
+
+Examples of scenarios you might arrange to trace include:
+
+@itemize
+@item Code flow within a function, @emph{excluding} subroutines
+it calls.  Use address range comparators to enable tracing
+for instruction access within that function's body.
+@item Code flow within a function, @emph{including} subroutines
+it calls.  Use the sequencer and address comparators to activate
+tracing on an ``entered function'' state, then deactivate it by
+exiting that state when the function's exit code is invoked.
+@item Code flow starting at the fifth invocation of a function,
+combining one of the above models with a counter.
+@item CPU data accesses to the registers for a particular device,
+using address range comparators and the ViewData logic.
+@item Such data accesses only during IRQ handling, combining the above
+model with sequencer triggers which on entry and exit to the IRQ handler.
+@item @emph{... more}
+@end itemize
+
+At this writing, September 2009, there are no Tcl utility
+procedures to help set up any common tracing scenarios.
+
 @deffn Command {etm analyze}
 Reads trace data into memory, if it wasn't already present.
 Decodes and prints the data that was collected.

diff --git a/src/target/etm.c b/src/target/etm.c
index cc80b68590e56dd6a0addfaaffd23807a50cbdd3..91c73a232db44e7a73f68b06c6aa8a930be91195 100644 (file)
--- a/src/target/etm.c
+++ b/src/target/etm.c
@@ -71,10 +71,14 @@ struct etm_reg_info {
  * Newer versions of ETM make some W/O registers R/W, and
  * provide definitions for some previously-unused bits.
  */
-static const struct etm_reg_info reg[] = {
+
+/* basic registers that are always there given the right ETM version */
+static const struct etm_reg_info etm_core[] = {
+       /* NOTE: we "know" ETM_CONFIG is listed first */
+       { ETM_CONFIG, 32, RO, 0x10, "ETM_CONFIG", },
+
        /* ETM Trace Registers */
        { ETM_CTRL, 32, RW, 0x10, "ETM_CTRL", },
-       { ETM_CONFIG, 32, RO, 0x10, "ETM_CONFIG", },
        { ETM_TRIG_EVENT, 17, WO, 0x10, "ETM_TRIG_EVENT", },
        { ETM_ASIC_CTRL,  8, WO, 0x10, "ETM_ASIC_CTRL", },
        { ETM_STATUS,  3, RO, 0x11, "ETM_STATUS", },
@@ -86,16 +90,25 @@ static const struct etm_reg_info reg[] = {
        { ETM_TRACE_EN_EVENT, 17, WO, 0x10, "ETM_TRACE_EN_EVENT", },
        { ETM_TRACE_EN_CTRL1, 26, WO, 0x10, "ETM_TRACE_EN_CTRL1", },
 
-       /* FIFOFULL configuration */
-       { ETM_FIFOFULL_REGION, 25, WO, 0x10, "ETM_FIFOFULL_REGION", },
-       { ETM_FIFOFULL_LEVEL,  8, WO, 0x10, "ETM_FIFOFULL_LEVEL", },
-
        /* ViewData configuration (data trace) */
        { ETM_VIEWDATA_EVENT, 17, WO, 0x10, "ETM_VIEWDATA_EVENT", },
        { ETM_VIEWDATA_CTRL1, 32, WO, 0x10, "ETM_VIEWDATA_CTRL1", },
        { ETM_VIEWDATA_CTRL2, 32, WO, 0x10, "ETM_VIEWDATA_CTRL2", },
        { ETM_VIEWDATA_CTRL3, 17, WO, 0x10, "ETM_VIEWDATA_CTRL3", },
 
+       /* REVISIT exclude VIEWDATA_CTRL2 when it's not there */
+
+       { 0x78, 12, WO, 0x20, "ETM_SYNC_FREQ", },
+       { 0x79, 32, RO, 0x20, "ETM_ID", },
+};
+
+static const struct etm_reg_info etm_fifofull[] = {
+       /* FIFOFULL configuration */
+       { ETM_FIFOFULL_REGION, 25, WO, 0x10, "ETM_FIFOFULL_REGION", },
+       { ETM_FIFOFULL_LEVEL,  8, WO, 0x10, "ETM_FIFOFULL_LEVEL", },
+};
+
+static const struct etm_reg_info etm_addr_comp[] = {
        /* Address comparator register pairs */
 #define ADDR_COMPARATOR(i) \
                { ETM_ADDR_COMPARATOR_VALUE + (i), 32, WO, 0x10, \
@@ -120,7 +133,9 @@ static const struct etm_reg_info reg[] = {
        ADDR_COMPARATOR(14),
        ADDR_COMPARATOR(15),
 #undef ADDR_COMPARATOR
+};
 
+static const struct etm_reg_info etm_data_comp[] = {
        /* Data Value Comparators (NOTE: odd addresses are reserved) */
 #define DATA_COMPARATOR(i) \
                { ETM_DATA_COMPARATOR_VALUE + 2*(i), 32, WO, 0x10, \
@@ -136,8 +151,9 @@ static const struct etm_reg_info reg[] = {
        DATA_COMPARATOR(6),
        DATA_COMPARATOR(7),
 #undef DATA_COMPARATOR
+};
 
-       /* Counters */
+static const struct etm_reg_info etm_counters[] = {
 #define COUNTER(i) \
                { ETM_COUNTER_RELOAD_VALUE + (i), 16, WO, 0x10, \
                                "ETM_COUNTER_RELOAD_VALUE" #i, }, \
@@ -152,8 +168,9 @@ static const struct etm_reg_info reg[] = {
        COUNTER(2),
        COUNTER(3),
 #undef COUNTER
+};
 
-       /* Sequencers */
+static const struct etm_reg_info etm_sequencer[] = {
 #define SEQ(i) \
                { ETM_SEQUENCER_EVENT + (i), 17, WO, 0x10, \
                                "ETM_SEQUENCER_EVENT" #i, }
@@ -166,7 +183,9 @@ static const struct etm_reg_info reg[] = {
 #undef SEQ
        /* 0x66 reserved */
        { ETM_SEQUENCER_STATE,  2, RO, 0x10, "ETM_SEQUENCER_STATE", },
+};
 
+static const struct etm_reg_info etm_outputs[] = {
 #define OUT(i) \
                { ETM_EXTERNAL_OUTPUT + (i), 17, WO, 0x10, \
                                "ETM_EXTERNAL_OUTPUT" #i, }
@@ -176,6 +195,7 @@ static const struct etm_reg_info reg[] = {
        OUT(2),
        OUT(3),
 #undef OUT
+};
 
 #if 0
        /* registers from 0x6c..0x7f were added after ETMv1.3 */
@@ -185,11 +205,7 @@ static const struct etm_reg_info reg[] = {
        { 0x6d, 32, RO, 0x20, "ETM_CONTEXTID_COMPARATOR_VALUE1", }
        { 0x6e, 32, RO, 0x20, "ETM_CONTEXTID_COMPARATOR_VALUE1", }
        { 0x6f, 32, RO, 0x20, "ETM_CONTEXTID_COMPARATOR_MASK", }
-
-       { 0x78, 12, WO, 0x20, "ETM_SYNC_FREQ", },
-       { 0x79, 32, RO, 0x20, "ETM_ID", },
 #endif
-};
 
 static int etm_reg_arch_type = -1;
 
@@ -224,43 +240,137 @@ static reg_t *etm_reg_lookup(etm_context_t *etm_ctx, unsigned id)
        return NULL;
 }
 
+static void etm_reg_add(unsigned bcd_vers, arm_jtag_t *jtag_info,
+               reg_cache_t *cache, etm_reg_t *ereg,
+               const struct etm_reg_info *r, unsigned nreg)
+{
+       reg_t *reg = cache->reg_list;
+
+       reg += cache->num_regs;
+       ereg += cache->num_regs;
+
+       /* add up to "nreg" registers from "r", if supported by this
+        * version of the ETM, to the specified cache.
+        */
+       for (; nreg--; r++) {
+
+               /* this ETM may be too old to have some registers */
+               if (r->bcd_vers > bcd_vers)
+                       continue;
+
+               reg->name = r->name;
+               reg->size = r->size;
+               reg->value = &ereg->value;
+               reg->arch_info = ereg;
+               reg->arch_type = etm_reg_arch_type;
+               reg++;
+               cache->num_regs++;
+
+               ereg->reg_info = r;
+               ereg->jtag_info = jtag_info;
+               ereg++;
+       }
+}
+
 reg_cache_t *etm_build_reg_cache(target_t *target,
                arm_jtag_t *jtag_info, etm_context_t *etm_ctx)
 {
        reg_cache_t *reg_cache = malloc(sizeof(reg_cache_t));
        reg_t *reg_list = NULL;
        etm_reg_t *arch_info = NULL;
-       int num_regs = ARRAY_SIZE(reg);
-       int i;
+       unsigned bcd_vers, config;
 
        /* register a register arch-type for etm registers only once */
        if (etm_reg_arch_type == -1)
-               etm_reg_arch_type = register_reg_arch_type(etm_get_reg, etm_set_reg_w_exec);
+               etm_reg_arch_type = register_reg_arch_type(etm_get_reg,
+                               etm_set_reg_w_exec);
 
        /* the actual registers are kept in two arrays */
-       reg_list = calloc(num_regs, sizeof(reg_t));
-       arch_info = calloc(num_regs, sizeof(etm_reg_t));
+       reg_list = calloc(128, sizeof(reg_t));
+       arch_info = calloc(128, sizeof(etm_reg_t));
 
        /* fill in values for the reg cache */
        reg_cache->name = "etm registers";
        reg_cache->next = NULL;
        reg_cache->reg_list = reg_list;
-       reg_cache->num_regs = num_regs;
-
-       /* set up registers */
-       for (i = 0; i < num_regs; i++)
-       {
-               const struct etm_reg_info *r = reg + i;
-
-               reg_list[i].name = r->name;
-               reg_list[i].size = r->size;
-               reg_list[i].value = &arch_info[i].value;
-               reg_list[i].arch_info = &arch_info[i];
-               reg_list[i].arch_type = etm_reg_arch_type;
-
-               arch_info[i].reg_info = r;
-               arch_info[i].jtag_info = jtag_info;
+       reg_cache->num_regs = 0;
+
+       /* add ETM_CONFIG, then parse its values to see
+        * which other registers exist in this ETM
+        */
+       etm_reg_add(0x10, jtag_info, reg_cache, arch_info,
+                       etm_core, 1);
+
+       etm_get_reg(reg_list);
+       etm_ctx->config = buf_get_u32((void *)&arch_info->value, 0, 32);
+       config = etm_ctx->config;
+
+       /* figure ETM version then add base registers */
+       if (config & (1 << 31)) {
+               bcd_vers = 0x20;
+               LOG_WARNING("ETMv2+ support is incomplete");
+
+               /* REVISIT read ID register, distinguish ETMv3.3 etc;
+                * don't presume trace start/stop support is present;
+                * and include any context ID comparator registers.
+                */
+       } else {
+               switch (config >> 28) {
+               case 7:
+               case 5:
+               case 3:
+                       bcd_vers = 0x13;
+                       break;
+               case 4:
+               case 2:
+                       bcd_vers = 0x12;
+                       break;
+               case 1:
+                       bcd_vers = 0x11;
+                       break;
+               case 0:
+                       bcd_vers = 0x10;
+                       break;
+               default:
+                       LOG_WARNING("Bad ETMv1 protocol %d", config >> 28);
+                       free(reg_cache);
+                       free(reg_list);
+                       free(arch_info);
+                       return ERROR_OK;
+               }
        }
+       etm_ctx->bcd_vers = bcd_vers;
+       LOG_INFO("ETM v%d.%d", bcd_vers >> 4, bcd_vers & 0xf);
+
+       etm_reg_add(bcd_vers, jtag_info, reg_cache, arch_info,
+                       etm_core + 1, ARRAY_SIZE(etm_core) - 1);
+
+       /* address and data comparators; counters; outputs */
+       etm_reg_add(bcd_vers, jtag_info, reg_cache, arch_info,
+                       etm_addr_comp, 4 * (0x0f & (config >> 0)));
+       etm_reg_add(bcd_vers, jtag_info, reg_cache, arch_info,
+                       etm_data_comp, 2 * (0x0f & (config >> 4)));
+       etm_reg_add(bcd_vers, jtag_info, reg_cache, arch_info,
+                       etm_counters, 4 * (0x07 & (config >> 13)));
+       etm_reg_add(bcd_vers, jtag_info, reg_cache, arch_info,
+                       etm_outputs, (0x07 & (config >> 20)));
+
+       /* FIFOFULL presence is optional
+        * REVISIT for ETMv1.2 and later, don't bother adding this
+        * unless ETM_SYS_CONFIG says it's also *supported* ...
+        */
+       if (config & (1 << 23))
+               etm_reg_add(bcd_vers, jtag_info, reg_cache, arch_info,
+                               etm_fifofull, ARRAY_SIZE(etm_fifofull));
+
+       /* sequencer is optional (for state-dependant triggering) */
+       if (config & (1 << 16))
+               etm_reg_add(bcd_vers, jtag_info, reg_cache, arch_info,
+                               etm_sequencer, ARRAY_SIZE(etm_sequencer));
+
+       /* REVISIT could realloc and likely save half the memory
+        * in the two chunks we allocated...
+        */
 
        /* the ETM might have an ETB connected */
        if (strcmp(etm_ctx->capture_driver->name, "etb") == 0)
@@ -271,6 +381,7 @@ reg_cache_t *etm_build_reg_cache(target_t *target,
                {
                        LOG_ERROR("etb selected as etm capture driver, but no ETB configured");
                        free(reg_cache);
+                       free(reg_list);
                        free(arch_info);
                        return ERROR_OK;
                }
@@ -1362,7 +1473,7 @@ static int handle_etm_info_command(struct command_context_s *cmd_ctx,
        target_t *target;
        armv4_5_common_t *armv4_5;
        arm7_9_common_t *arm7_9;
-       reg_t *etm_config_reg;
+       etm_context_t *etm;
        reg_t *etm_sys_config_reg;
 
        int max_port_size;
@@ -1375,31 +1486,45 @@ static int handle_etm_info_command(struct command_context_s *cmd_ctx,
                return ERROR_OK;
        }
 
-       if (!arm7_9->etm_ctx)
+       etm = arm7_9->etm_ctx;
+       if (!etm)
        {
                command_print(cmd_ctx, "current target doesn't have an ETM configured");
                return ERROR_OK;
        }
 
-       etm_config_reg = etm_reg_lookup(arm7_9->etm_ctx, ETM_CONFIG);
-       if (!etm_config_reg)
-               return ERROR_OK;
-       etm_sys_config_reg = etm_reg_lookup(arm7_9->etm_ctx, ETM_SYS_CONFIG);
-       if (!etm_sys_config_reg)
-               return ERROR_OK;
-
-       etm_get_reg(etm_config_reg);
-       command_print(cmd_ctx, "pairs of address comparators: %i", (int)buf_get_u32(etm_config_reg->value, 0, 4));
-       command_print(cmd_ctx, "pairs of data comparators: %i", (int)buf_get_u32(etm_config_reg->value, 4, 4));
-       command_print(cmd_ctx, "memory map decoders: %i", (int)buf_get_u32(etm_config_reg->value, 8, 5));
-       command_print(cmd_ctx, "number of counters: %i", (int)buf_get_u32(etm_config_reg->value, 13, 3));
+       command_print(cmd_ctx, "ETM v%d.%d",
+                       etm->bcd_vers >> 4, etm->bcd_vers & 0xf);
+       command_print(cmd_ctx, "pairs of address comparators: %i",
+                       (etm->config >> 0) & 0x0f);
+       command_print(cmd_ctx, "data comparators: %i",
+                       (etm->config >> 4) & 0x0f);
+       command_print(cmd_ctx, "memory map decoders: %i",
+                       (etm->config >> 8) & 0x1f);
+       command_print(cmd_ctx, "number of counters: %i",
+                       (etm->config >> 13) & 0x07);
        command_print(cmd_ctx, "sequencer %spresent",
-                       (buf_get_u32(etm_config_reg->value, 16, 1) == 1) ? "" : "not ");
-       command_print(cmd_ctx, "number of ext. inputs: %i", (int)buf_get_u32(etm_config_reg->value, 17, 3));
-       command_print(cmd_ctx, "number of ext. outputs: %i",(int) buf_get_u32(etm_config_reg->value, 20, 3));
+                       (etm->config & (1 << 16)) ? "" : "not ");
+       command_print(cmd_ctx, "number of ext. inputs: %i",
+                       (etm->config >> 17) & 0x07);
+       command_print(cmd_ctx, "number of ext. outputs: %i",
+                       (etm->config >> 20) & 0x07);
        command_print(cmd_ctx, "FIFO full %spresent",
-                       (buf_get_u32(etm_config_reg->value, 23, 1) == 1) ? "" : "not ");
-       command_print(cmd_ctx, "protocol version: %i", (int)buf_get_u32(etm_config_reg->value, 28, 3));
+                       (etm->config & (1 << 23)) ? "" : "not ");
+       if (etm->bcd_vers < 0x20)
+               command_print(cmd_ctx, "protocol version: %i",
+                               (etm->config >> 28) & 0x07);
+       else {
+               command_print(cmd_ctx, "trace start/stop %spresent",
+                               (etm->config & (1 << 26)) ? "" : "not ");
+               command_print(cmd_ctx, "number of context comparators: %i",
+                               (etm->config >> 24) & 0x03);
+       }
+
+       /* SYS_CONFIG isn't present before ETMv1.2 */
+       etm_sys_config_reg = etm_reg_lookup(etm, ETM_SYS_CONFIG);
+       if (!etm_sys_config_reg)
+               return ERROR_OK;
 
        etm_get_reg(etm_sys_config_reg);
 

diff --git a/src/target/etm.h b/src/target/etm.h
index 6b4938aa782693c1317ebdb81eba2b6da9c02541..b2426c7497e97ffc73c0f5c6024d8be0f22a1a12 100644 (file)
--- a/src/target/etm.h
+++ b/src/target/etm.h
@@ -165,6 +165,8 @@ typedef struct etm_context_s
        bool data_half;                 /* port half on a 16 bit port */
        bool pc_ok;                     /* full PC has been acquired */
        bool ptr_ok;                    /* whether last_ptr is valid */
+       uint8_t bcd_vers;               /* e.g. 0x13 == ETMv1.3 */
+       uint32_t config;                /* cache of ETM_CONFIG value */
        uint32_t current_pc;            /* current program counter */
        uint32_t last_branch;           /* last branch address output */
        uint32_t last_branch_reason;    /* type of last branch encountered */