Cortex-M3: minor breakpoint cleanup

Shrink some lines, add some comments, simplify some tests.
During debug startup, log the core revision level too.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>

diff --git a/src/target/cortex_m3.c b/src/target/cortex_m3.c
index 556928f826044954916fe21e45c46930fe82729c..9685821977e0e97c6b622b98a992b6b5ebf6a34f 100644 (file)
--- a/src/target/cortex_m3.c
+++ b/src/target/cortex_m3.c
@@ -42,6 +42,9 @@
 
 /* NOTE:  most of this should work fine for the Cortex-M1 and
  * Cortex-M0 cores too, although they're ARMv6-M not ARMv7-M.
+ * Some differences:  M0/M1 doesn't have FBP remapping or the
+ * DWT tracing/profiling support.  (So the cycle counter will
+ * not be usable; the other stuff isn't currently used here.)
  *
  * Although there are some workarounds for errata seen only in r0p0
  * silicon, such old parts are hard to find and thus not much tested
@@ -579,7 +582,7 @@ static void cortex_m3_enable_breakpoints(struct target *target)
        /* set any pending breakpoints */
        while (breakpoint)
        {
-               if (breakpoint->set == 0)
+               if (!breakpoint->set)
                        cortex_m3_set_breakpoint(target, breakpoint);
                breakpoint = breakpoint->next;
        }
@@ -936,16 +939,25 @@ cortex_m3_set_breakpoint(struct target *target, struct breakpoint *breakpoint)
        else if (breakpoint->type == BKPT_SOFT)
        {
                uint8_t code[4];
+
+               /* NOTE: on ARMv6-M and ARMv7-M, BKPT(0xab) is used for
+                * semihosting; don't use that.  Otherwise the BKPT
+                * parameter is arbitrary.
+                */
                buf_set_u32(code, 0, 32, ARMV5_T_BKPT(0x11));
-               if ((retval = target_read_memory(target, breakpoint->address & 0xFFFFFFFE, breakpoint->length, 1, breakpoint->orig_instr)) != ERROR_OK)
-               {
+               retval = target_read_memory(target,
+                               breakpoint->address & 0xFFFFFFFE,
+                               breakpoint->length, 1,
+                               breakpoint->orig_instr);
+               if (retval != ERROR_OK)
                        return retval;
-               }
-               if ((retval = target_write_memory(target, breakpoint->address & 0xFFFFFFFE, breakpoint->length, 1, code)) != ERROR_OK)
-               {
+               retval = target_write_memory(target,
+                               breakpoint->address & 0xFFFFFFFE,
+                               breakpoint->length, 1,
+                               code);
+               if (retval != ERROR_OK)
                        return retval;
-               }
-               breakpoint->set = 0x11; /* Any nice value but 0 */
+               breakpoint->set = true;
        }
 
        LOG_DEBUG("BPID: %d, Type: %d, Address: 0x%08" PRIx32 " Length: %d (set=%d)",
@@ -1008,7 +1020,7 @@ cortex_m3_unset_breakpoint(struct target *target, struct breakpoint *breakpoint)
                        }
                }
        }
-       breakpoint->set = 0;
+       breakpoint->set = false;
 
        return ERROR_OK;
 }
@@ -1187,7 +1199,7 @@ cortex_m3_unset_watchpoint(struct target *target, struct watchpoint *watchpoint)
        target_write_u32(target, comparator->dwt_comparator_address + 8,
                        comparator->function);
 
-       watchpoint->set = 0;
+       watchpoint->set = false;
 
        return ERROR_OK;
 }
@@ -1273,7 +1285,7 @@ static void cortex_m3_enable_watchpoints(struct target *target)
        /* set any pending watchpoints */
        while (watchpoint)
        {
-               if (watchpoint->set == 0)
+               if (!watchpoint->set)
                        cortex_m3_set_watchpoint(target, watchpoint);
                watchpoint = watchpoint->next;
        }
@@ -1647,7 +1659,8 @@ static int cortex_m3_examine(struct target *target)
                        return retval;
 
                if (((cpuid >> 4) & 0xc3f) == 0xc23)
-                       LOG_DEBUG("CORTEX-M3 processor detected");
+                       LOG_DEBUG("Cortex-M3 r%dp%d processor detected",
+                               (cpuid >> 20) & 0xf, (cpuid >> 0) & 0xf);
                LOG_DEBUG("cpuid: 0x%8.8" PRIx32 "", cpuid);
 
                /* NOTE: FPB and DWT are both optional. */