Added enterbkpt option to assist with debugging

tangrs · tangrs · commit bd369a505cbf · 2013-04-15T20:17:10.000+10:00
diff --git a/Makefile b/Makefile
@@ -2,7 +2,7 @@ include libfdt/Makefile.libfdt
 
 GCC = nspire-gcc
 LD = nspire-ld
-GCCFLAGS = -Os -nostdlib -Wall -W -marm -Ilibfdt/
+GCCFLAGS = -mcpu=arm926ej-s -Os -nostdlib -Wall -W -marm -Ilibfdt/
 # Feel free to comment the following lines out if you're
 # not using git or you don't want the build date included
 BUILDFLAGS = -DBUILD_DATE="\"$(shell date --rfc-2822)\""
diff --git a/cmd.c b/cmd.c
@@ -88,6 +88,7 @@ int process_cmd(char * cmd) {
     DEFINE_COMMAND(probemem, force_guess_memory);
     DEFINE_COMMAND(poke, poke);
     DEFINE_COMMAND(peek, peek);
+    DEFINE_COMMAND(enterbkpt, break_on_entry);
     /*
         End command list. Do not add any more after here
     */
diff --git a/common.c b/common.c
@@ -99,6 +99,10 @@ void poke(char *arg) {
     peek(arg);
 }
 
+void break_on_entry(char *arg) {
+    settings.break_on_entry = 1;
+}
+
 void dump_settings(char * ignored __attribute__((unused))) {
     HEADER_LEVEL0(kernel);
         DUMP_LEVEL1(settings.kernel, addr);
@@ -131,6 +135,7 @@ void dump_settings(char * ignored __attribute__((unused))) {
     DUMP_LEVEL0(settings, initrd_loaded);
     DUMP_LEVEL0(settings, kernel_loaded);
     DUMP_LEVEL0(settings, dtb_loaded);
+    DUMP_LEVEL0(settings, break_on_entry);
 
     printl("kernel_cmdline = \"%s\"" NEWLINE, settings.kernel_cmdline);
     printl("serialnr = 0x%x%x" NEWLINE, settings.serialnr[1], settings.serialnr[0]);
diff --git a/common.h b/common.h
@@ -60,6 +60,7 @@ struct params {
     unsigned initrd_loaded:1;
     unsigned kernel_loaded:1;
     unsigned dtb_loaded:1;
+    unsigned break_on_entry:1;
 };
 
 extern struct params settings;
@@ -72,4 +73,6 @@ void setget_rdisksize(char * arg);
 void poke(char *arg);
 void peek(char *arg);
 
+void break_on_entry(char *arg);
+
 #endif
diff --git a/kernel.c b/kernel.c
@@ -56,6 +56,10 @@ void kernel_boot(char * ignored __attribute__((unused))) {
                  "mcr p15, 0, r0, c1, c0, 0 \n"
                  : : : "r0" );
     /* Bye bye */
+    if (settings.break_on_entry) {
+        asm volatile("bkpt #0");
+    }
+
     entry(0, settings.machine_id, settings.boot_param.start);
     __builtin_unreachable();
 }
