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-rw-r--r--src/cortexm.c159
-rw-r--r--src/gdb_main.c59
-rw-r--r--src/include/target.h7
3 files changed, 176 insertions, 49 deletions
diff --git a/src/cortexm.c b/src/cortexm.c
index 36319ee..179fb36 100644
--- a/src/cortexm.c
+++ b/src/cortexm.c
@@ -204,6 +204,9 @@ static int cortexm_check_hw_wp(struct target_s *target, uint32_t *addr);
#define CORTEXM_MAX_WATCHPOINTS 4 /* architecture says up to 15, no implementation has > 4 */
#define CORTEXM_MAX_BREAKPOINTS 6 /* architecture says up to 127, no implementation has > 6 */
+static int cortexm_hostio_request(target *t);
+static void cortexm_hostio_reply(target *t, int32_t retcode, uint32_t errcode);
+
struct cortexm_priv {
bool stepping;
bool on_bkpt;
@@ -219,6 +222,10 @@ struct cortexm_priv {
unsigned hw_breakpoint_max;
/* Copy of DEMCR for vector-catch */
uint32_t demcr;
+ /* Semihosting state */
+ uint32_t syscall;
+ uint32_t errno;
+ uint32_t byte_count;
};
/* Register number tables */
@@ -335,6 +342,8 @@ cortexm_probe(struct target_s *target)
target->halt_resume = cortexm_halt_resume;
target->regs_size = sizeof(regnum_cortex_m);
+ target->hostio_reply = cortexm_hostio_reply;
+
target_add_commands(target, cortexm_cmd_list, cortexm_driver_str);
/* Probe for FP extension */
@@ -595,6 +604,23 @@ cortexm_halt_wait(struct target_s *target)
/* Remember if we stopped on a breakpoint */
priv->on_bkpt = dfsr & (CORTEXM_DFSR_BKPT);
+ if (priv->on_bkpt) {
+ /* If we've hit a programmed breakpoint, check for semihosting
+ * call. */
+ uint32_t pc = cortexm_pc_read(target);
+ uint16_t bkpt_instr;
+ target_mem_read_bytes(target, (uint8_t *)&bkpt_instr, pc, 2);
+ if (bkpt_instr == 0xBEAB) {
+ int n = cortexm_hostio_request(target);
+ if (n > 0) {
+ target_halt_resume(target, priv->stepping);
+ return 0;
+ } else if (n < 0) {
+ return -1;
+ }
+ }
+ }
+
if (dfsr & (CORTEXM_DFSR_BKPT | CORTEXM_DFSR_DWTTRAP))
return SIGTRAP;
@@ -861,3 +887,136 @@ static bool cortexm_vector_catch(target *t, int argc, char *argv[])
return true;
}
+
+/* Semihosting support */
+/* ARM Semihosting syscall numbers, from ARM doc DUI0471C, Chapter 8 */
+#define SYS_CLOSE 0x02
+#define SYS_CLOCK 0x10
+#define SYS_ELAPSED 0x30
+#define SYS_ERRNO 0x13
+#define SYS_FLEN 0x0C
+#define SYS_GET_CMDLINE 0x15
+#define SYS_HEAPINFO 0x16
+#define SYS_ISERROR 0x08
+#define SYS_ISTTY 0x09
+#define SYS_OPEN 0x01
+#define SYS_READ 0x06
+#define SYS_READC 0x07
+#define SYS_REMOVE 0x0E
+#define SYS_RENAME 0x0F
+#define SYS_SEEK 0x0A
+#define SYS_SYSTEM 0x12
+#define SYS_TICKFREQ 0x31
+#define SYS_TIME 0x11
+#define SYS_TMPNAM 0x0D
+#define SYS_WRITE 0x05
+#define SYS_WRITEC 0x03
+#define SYS_WRITE0 0x04
+
+#define FILEIO_O_RDONLY 0
+#define FILEIO_O_WRONLY 1
+#define FILEIO_O_RDWR 2
+#define FILEIO_O_APPEND 0x008
+#define FILEIO_O_CREAT 0x200
+#define FILEIO_O_TRUNC 0x400
+
+#define FILEIO_SEEK_SET 0
+#define FILEIO_SEEK_CUR 1
+#define FILEIO_SEEK_END 2
+
+static int cortexm_hostio_request(target *t)
+{
+ ADIv5_AP_t *ap = adiv5_target_ap(t);
+ struct cortexm_priv *priv = ap->priv;
+ uint32_t arm_regs[t->regs_size];
+ uint32_t params[4];
+
+ target_regs_read(t, arm_regs);
+ target_mem_read_words(t, params, arm_regs[1], sizeof(params));
+ priv->syscall = arm_regs[0];
+
+ DEBUG("syscall 0x%x (%x %x %x %x)\n", priv->syscall,
+ params[0], params[1], params[2], params[3]);
+ switch (priv->syscall) {
+ case SYS_OPEN:{ /* open */
+ /* Translate stupid fopen modes to open flags.
+ * See DUI0471C, Table 8-3 */
+ const uint32_t flags[] = {
+ FILEIO_O_RDONLY, /* r, rb */
+ FILEIO_O_RDWR, /* r+, r+b */
+ FILEIO_O_WRONLY | FILEIO_O_CREAT | FILEIO_O_TRUNC,/*w*/
+ FILEIO_O_RDWR | FILEIO_O_CREAT | FILEIO_O_TRUNC,/*w+*/
+ FILEIO_O_WRONLY | FILEIO_O_CREAT | FILEIO_O_APPEND,/*a*/
+ FILEIO_O_RDWR | FILEIO_O_CREAT | FILEIO_O_APPEND,/*a+*/
+ };
+ gdb_putpacket_f("Fopen,%08X/%X,%08X,%08X",
+ params[0], params[2] + 1,
+ flags[params[1] >> 1], 0644);
+ break;
+ }
+ case SYS_CLOSE: /* close */
+ gdb_putpacket_f("Fclose,%08X", params[0]);
+ break;
+ case SYS_READ: /* read */
+ priv->byte_count = params[2];
+ gdb_putpacket_f("Fread,%08X,%08X,%08X",
+ params[0], params[1], params[2]);
+ break;
+ case SYS_WRITE: /* write */
+ priv->byte_count = params[2];
+ gdb_putpacket_f("Fwrite,%08X,%08X,%08X",
+ params[0], params[1], params[2]);
+ break;
+ case SYS_ISTTY: /* isatty */
+ gdb_putpacket_f("Fisatty,%08X", params[0]);
+ break;
+ case SYS_SEEK: /* lseek */
+ gdb_putpacket_f("Flseek,%08X,%08X,%08X",
+ params[0], params[1], FILEIO_SEEK_SET);
+ break;
+ case SYS_RENAME:/* rename */
+ gdb_putpacket_f("Frename,%08X/%X,%08X/%X",
+ params[0], params[1] + 1,
+ params[2], params[3] + 1);
+ break;
+ case SYS_REMOVE:/* unlink */
+ gdb_putpacket_f("Funlink,%08X/%X", params[0], params[1] + 1);
+ break;
+ case SYS_SYSTEM:/* system */
+ gdb_putpacket_f("Fsystem,%08X/%X", params[0], params[1] + 1);
+ break;
+
+ case SYS_FLEN: /* Not supported, fake success */
+ priv->errno = 0;
+ return 1;
+
+ case SYS_ERRNO: /* Return last errno from GDB */
+ arm_regs[0] = priv->errno;
+ target_regs_write(t, arm_regs);
+ return 1;
+
+ case SYS_TIME: /* gettimeofday */
+ /* FIXME How do we use gdb's gettimeofday? */
+ default:
+ return 0;
+ }
+
+ return -1;
+}
+
+static void cortexm_hostio_reply(target *t, int32_t retcode, uint32_t errcode)
+{
+ ADIv5_AP_t *ap = adiv5_target_ap(t);
+ struct cortexm_priv *priv = ap->priv;
+ uint32_t arm_regs[t->regs_size];
+
+ DEBUG("syscall return ret=%d errno=%d\n", retcode, errcode);
+ target_regs_read(t, arm_regs);
+ if (((priv->syscall == SYS_READ) || (priv->syscall == SYS_WRITE)) &&
+ (retcode > 0))
+ retcode = priv->byte_count - retcode;
+ arm_regs[0] = retcode;
+ target_regs_write(t, arm_regs);
+ priv->errno = errcode;
+}
+
diff --git a/src/gdb_main.c b/src/gdb_main.c
index 887b9ac..69d5ed1 100644
--- a/src/gdb_main.c
+++ b/src/gdb_main.c
@@ -76,7 +76,6 @@ gdb_main(void)
int size;
bool single_step = false;
char last_activity = 0;
- uint32_t semihost_read_bytes = 0;
DEBUG("Entring GDB protocol main loop\n");
/* GDB protocol main loop */
@@ -161,6 +160,7 @@ gdb_main(void)
break;
}
+ last_activity = pbuf[0];
/* Wait for target halt */
while(!(sig = target_halt_wait(cur_target))) {
unsigned char c = gdb_if_getchar_to(0);
@@ -171,42 +171,9 @@ gdb_main(void)
}
SET_RUN_STATE(0);
- uint32_t arm_regs[cur_target->regs_size];
- uint32_t semihost_buf[4];
- target_regs_read(cur_target, arm_regs);
- target_mem_read_bytes(cur_target, (uint8_t *)semihost_buf, arm_regs[15], 2);
- /* Is this a semihosting breakpoint? */
- if ((semihost_buf[0] & 0xFFFF) == 0xBEAB) {
- last_activity = pbuf[0];
- semihost_read_bytes = 0;
- target_mem_read_words(cur_target, semihost_buf, arm_regs[1], sizeof(semihost_buf));
-
- switch (arm_regs[0]) {
- case 0x09: /* SYS_ISTTY */
- arm_regs[0] = 1; /* it's a tty */
- target_regs_write(cur_target, arm_regs);
- /* fall-through */
- case 0x01: /* SYS_OPEN */
- case 0x0C: /* SYS_FLEN */
- /* pretend it's successful, r0 is non-zero already */
- goto continue_activity;
- case 0x13: /* SYS_ERRNO */
- arm_regs[0] = 4; /* EINTR */
- target_regs_write(cur_target, arm_regs);
- goto continue_activity;
- case 0x05: /* SYS_WRITE */
- gdb_putpacket_f("Fwrite,1,%08X,%08X",
- semihost_buf[1], semihost_buf[2]);
- arm_regs[0] = 0; /* pretend it's always successful */
- target_regs_write(cur_target, arm_regs);
- continue;
- case 0x06: /* SYS_READ */
- gdb_putpacket_f("Fread,0,%08X,%08X",
- semihost_buf[1], semihost_buf[2]);
- semihost_read_bytes = semihost_buf[2];
- continue;
- }
- }
+ /* Negative signal indicates we're in a syscall */
+ if (sig < 0)
+ break;
/* Report reason for halt */
if(target_check_hw_wp(cur_target, &watch_addr)) {
@@ -218,23 +185,17 @@ gdb_main(void)
break;
}
case 'F': { /* Semihosting call finished */
- int bytes, errcode, items;
+ int retcode, errcode, items;
char c, *p;
if (pbuf[1] == '-')
p = &pbuf[2];
else
p = &pbuf[1];
- items = sscanf(p, "%x,%x,%c", &bytes, &errcode, &c);
-
- if (semihost_read_bytes) {
- uint32_t arm_regs[cur_target->regs_size];
- target_regs_read(cur_target, arm_regs);
- if (items == 3 && c == 'C')
- arm_regs[0] = -1;
- else
- arm_regs[0] = semihost_read_bytes - bytes;
- target_regs_write(cur_target, arm_regs);
- }
+ items = sscanf(p, "%x,%x,%c", &retcode, &errcode, &c);
+ if (pbuf[1] == '-')
+ retcode = -retcode;
+
+ target_hostio_reply(cur_target, retcode, errcode);
/* if break is requested */
if (items == 3 && c == 'C') {
diff --git a/src/include/target.h b/src/include/target.h
index cd3079c..b83a2e9 100644
--- a/src/include/target.h
+++ b/src/include/target.h
@@ -116,6 +116,10 @@ target *target_attach(target *t, target_destroy_callback destroy_cb);
#define target_flash_write(target, dest, src, len) \
(target)->flash_write((target), (dest), (src), (len))
+/* Host I/O */
+#define target_hostio_reply(target, recode, errcode) \
+ (target)->hostio_reply((target), (retcode), (errcode))
+
struct target_s {
/* Notify controlling debugger if target is lost */
@@ -171,6 +175,9 @@ struct target_s {
int (*flash_write)(struct target_s *target, uint32_t dest,
const uint8_t *src, int len);
+ /* Host I/O support */
+ void (*hostio_reply)(target *t, int32_t retcode, uint32_t errcode);
+
const char *driver;
struct target_command_s *commands;