[U-Boot] [RFC PATCH v1 2/2] arm:kgdb add KGDB support for arm platform
Peng Fan
Peng.Fan at freescale.com
Sat Nov 1 06:12:56 CET 2014
The register save/restore:
Use get_bad_stack and bad_save_user_regs to save regs.
Introduce und_restore_regs to restore the previous regs before
trigger a breakpoint.
Signed-off-by: Peng Fan <Peng.Fan at freescale.com>
---
arch/arm/include/asm/proc-armv/ptrace.h | 2 +-
arch/arm/include/asm/signal.h | 1 +
arch/arm/lib/Makefile | 3 +
arch/arm/lib/crt0.S | 4 +
arch/arm/lib/interrupts.c | 24 ++++
arch/arm/lib/kgdb/kgdb.c | 231 ++++++++++++++++++++++++++++++++
arch/arm/lib/kgdb/setjmp.S | 20 +++
arch/arm/lib/vectors.S | 28 ++++
8 files changed, 312 insertions(+), 1 deletion(-)
diff --git a/arch/arm/include/asm/proc-armv/ptrace.h b/arch/arm/include/asm/proc-armv/ptrace.h
index 71df5a9..33fe587 100644
--- a/arch/arm/include/asm/proc-armv/ptrace.h
+++ b/arch/arm/include/asm/proc-armv/ptrace.h
@@ -58,7 +58,7 @@ struct pt_regs {
stack during a system call. */
struct pt_regs {
- long uregs[18];
+ unsigned long uregs[18];
};
#define ARM_cpsr uregs[16]
diff --git a/arch/arm/include/asm/signal.h b/arch/arm/include/asm/signal.h
new file mode 100644
index 0000000..7b1573c
--- /dev/null
+++ b/arch/arm/include/asm/signal.h
@@ -0,0 +1 @@
+#include <asm-generic/signal.h>
diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile
index 1ef2400..c543563 100644
--- a/arch/arm/lib/Makefile
+++ b/arch/arm/lib/Makefile
@@ -52,3 +52,6 @@ endif
ifneq (,$(findstring -mabi=aapcs-linux,$(PLATFORM_CPPFLAGS)))
extra-y += eabi_compat.o
endif
+
+obj-$(CONFIG_CMD_KGDB) += kgdb/setjmp.o
+obj-$(CONFIG_CMD_KGDB) += kgdb/kgdb.o
diff --git a/arch/arm/lib/crt0.S b/arch/arm/lib/crt0.S
index 29cdad0..d96e70b 100644
--- a/arch/arm/lib/crt0.S
+++ b/arch/arm/lib/crt0.S
@@ -99,9 +99,13 @@ clr_gd:
sub r9, r9, #GD_SIZE /* new GD is below bd */
adr lr, here
+#ifndef CONFIG_CMD_KGDB
ldr r0, [r9, #GD_RELOC_OFF] /* r0 = gd->reloc_off */
add lr, lr, r0
ldr r0, [r9, #GD_RELOCADDR] /* r0 = gd->relocaddr */
+#else
+ ldr r0, =__image_copy_start
+#endif
b relocate_code
here:
diff --git a/arch/arm/lib/interrupts.c b/arch/arm/lib/interrupts.c
index 4dacfd9..d16bd58 100644
--- a/arch/arm/lib/interrupts.c
+++ b/arch/arm/lib/interrupts.c
@@ -22,6 +22,7 @@
#include <common.h>
#include <asm/proc-armv/ptrace.h>
#include <asm/u-boot-arm.h>
+#include <kgdb.h>
DECLARE_GLOBAL_DATA_PTR;
@@ -160,9 +161,32 @@ void show_regs (struct pt_regs *regs)
void do_undefined_instruction (struct pt_regs *pt_regs)
{
+#if defined(CONFIG_CMD_KGDB)
+ unsigned long *tmp_pc = NULL;
+
+ pt_regs->ARM_pc -= 4;
+ tmp_pc = (unsigned long *)pt_regs->ARM_pc;
+
+ if (*tmp_pc == 0xe7ffdeff) {
+ pt_regs->ARM_pc += 4;
+ if (debugger_exception_handler &&
+ debugger_exception_handler(pt_regs)) {
+ return;
+ }
+ } else if (*tmp_pc == 0xe7ffdefe) {
+ if (debugger_exception_handler &&
+ debugger_exception_handler(pt_regs)) {
+ return;
+ }
+ } else {
+ printf("DCache/ICACHE May need flush\n");
+ return;
+ }
+#else
printf ("undefined instruction\n");
show_regs (pt_regs);
bad_mode ();
+#endif
}
void do_software_interrupt (struct pt_regs *pt_regs)
diff --git a/arch/arm/lib/kgdb/kgdb.c b/arch/arm/lib/kgdb/kgdb.c
new file mode 100644
index 0000000..6b2e542
--- /dev/null
+++ b/arch/arm/lib/kgdb/kgdb.c
@@ -0,0 +1,231 @@
+#include <common.h>
+#include <command.h>
+#include <kgdb.h>
+#include <asm/signal.h>
+#include <asm/processor.h>
+
+#define KGDB_ARM_GP_REGS 16
+#define KGDB_ARM_FP_REGS 8
+#define KGDB_ARM_EXTRA_REGS 2
+#define KGDB_ARM_MAX_REGS (KGDB_ARM_GP_REGS +\
+ (KGDB_ARM_FP_REGS * 3) +\
+ KGDB_ARM_EXTRA_REGS)
+#define KGDB_NUMREGBYTES (KGDB_ARM_MAX_REGS << 2)
+
+enum arm_regs {
+ KGDB_ARM_R0,
+ KGDB_ARM_R1,
+ KGDB_ARM_R2,
+ KGDB_ARM_R3,
+ KGDB_ARM_R4,
+ KGDB_ARM_R5,
+ KGDB_ARM_R6,
+ KGDB_ARM_R7,
+ KGDB_ARM_R8,
+ KGDB_ARM_R9,
+ KGDB_ARM_R10,
+ KGDB_ARM_FP,
+ KGDB_ARM_IP,
+ KGDB_ARM_SP,
+ KGDB_ARM_LR,
+ KGDB_ARM_PC,
+ KGDB_ARM_CPSR = KGDB_ARM_MAX_REGS - 1
+};
+
+void kgdb_enter(struct pt_regs *regs, kgdb_data *kdp)
+{
+ disable_interrupts();
+
+ kdp->sigval = kgdb_trap(regs);
+ kdp->nregs = 2;
+ kdp->regs[0].num = KGDB_ARM_PC;
+ kdp->regs[0].val = regs->ARM_pc;
+
+ kdp->regs[1].num = KGDB_ARM_SP;
+ kdp->regs[1].val = regs->ARM_sp;
+
+ return;
+}
+
+void kgdb_exit(struct pt_regs *regs, kgdb_data *kdp)
+{
+ /* Mark Not sure ??? */
+
+ if (kdp->extype & KGDBEXIT_WITHADDR) {
+ regs->ARM_pc = kdp->exaddr;
+ printf("KGDBEXIT_WITHADDR 0x%lx\n", regs->ARM_pc);
+ }
+
+ switch (kdp->extype & KGDBEXIT_TYPEMASK) {
+ case KGDBEXIT_KILL:
+ printf("KGDBEXIT_KILL:\n");
+ break;
+ case KGDBEXIT_CONTINUE:
+ printf("KGDBEXIT_CONTINUE\n");
+ break;
+ case KGDBEXIT_SINGLE:
+ printf("KGDBEXIT_SINGLE\n");
+ break;
+ default:
+ printf("KGDBEXIT : %d\n", kdp->extype);
+ }
+
+ enable_interrupts();
+}
+
+int kgdb_trap(struct pt_regs *regs)
+{
+ /* Mark Not sure ??? */
+ return SIGTRAP;
+}
+
+int kgdb_getregs(struct pt_regs *regs, char *buf, int max)
+{
+ unsigned long *gdb_regs = (unsigned long *)buf;
+
+ if (max < KGDB_NUMREGBYTES)
+ kgdb_error(KGDBERR_NOSPACE);
+
+ if ((unsigned long)gdb_regs & 3)
+ kgdb_error(KGDBERR_ALIGNFAULT);
+
+ gdb_regs[KGDB_ARM_R0] = regs->ARM_r0;
+ gdb_regs[KGDB_ARM_R1] = regs->ARM_r1;
+ gdb_regs[KGDB_ARM_R2] = regs->ARM_r2;
+ gdb_regs[KGDB_ARM_R3] = regs->ARM_r3;
+ gdb_regs[KGDB_ARM_R4] = regs->ARM_r4;
+ gdb_regs[KGDB_ARM_R5] = regs->ARM_r5;
+ gdb_regs[KGDB_ARM_R6] = regs->ARM_r6;
+ gdb_regs[KGDB_ARM_R7] = regs->ARM_r7;
+ gdb_regs[KGDB_ARM_R8] = regs->ARM_r8;
+ gdb_regs[KGDB_ARM_R9] = regs->ARM_r9;
+ gdb_regs[KGDB_ARM_R10] = regs->ARM_r10;
+ gdb_regs[KGDB_ARM_IP] = regs->ARM_ip;
+ gdb_regs[KGDB_ARM_FP] = regs->ARM_fp;
+ /* set sp */
+ gdb_regs[KGDB_ARM_SP] = (unsigned long)regs;
+ gdb_regs[KGDB_ARM_LR] = regs->ARM_lr;
+ gdb_regs[KGDB_ARM_PC] = regs->ARM_pc;
+ gdb_regs[KGDB_ARM_CPSR] = regs->ARM_cpsr;
+
+ return KGDB_NUMREGBYTES;
+}
+
+void kgdb_putreg(struct pt_regs *regs, int regno, char *buf, int length)
+{
+ unsigned long *ptr = (unsigned long *)buf;
+
+ if (regno < 0 || regno >= 16)
+ kgdb_error(KGDBERR_BADPARAMS);
+
+ if (length < 4)
+ kgdb_error(KGDBERR_NOSPACE);
+
+ if ((unsigned long)ptr & 3)
+ kgdb_error(KGDBERR_ALIGNFAULT);
+
+ switch (regno) {
+ case KGDB_ARM_R0:
+ regs->ARM_r0 = *ptr;
+ break;
+ case KGDB_ARM_R1:
+ regs->ARM_r1 = *ptr;
+ break;
+ case KGDB_ARM_R2:
+ regs->ARM_r2 = *ptr;
+ break;
+ case KGDB_ARM_R3:
+ regs->ARM_r3 = *ptr;
+ break;
+ case KGDB_ARM_R4:
+ regs->ARM_r4 = *ptr;
+ break;
+ case KGDB_ARM_R5:
+ regs->ARM_r5 = *ptr;
+ break;
+ case KGDB_ARM_R6:
+ regs->ARM_r6 = *ptr;
+ break;
+ case KGDB_ARM_R7:
+ regs->ARM_r7 = *ptr;
+ break;
+ case KGDB_ARM_R8:
+ regs->ARM_r8 = *ptr;
+ break;
+ case KGDB_ARM_R9:
+ regs->ARM_r9 = *ptr;
+ break;
+ case KGDB_ARM_R10:
+ regs->ARM_r10 = *ptr;
+ break;
+ case KGDB_ARM_FP:
+ regs->ARM_fp = *ptr;
+ break;
+ case KGDB_ARM_IP:
+ regs->ARM_ip = *ptr;
+ break;
+ case KGDB_ARM_SP:
+ regs->ARM_sp = *ptr;
+ break;
+ case KGDB_ARM_LR:
+ regs->ARM_lr = *ptr;
+ break;
+ case KGDB_ARM_PC:
+ regs->ARM_pc = *ptr;
+ break;
+ case KGDB_ARM_CPSR:
+ regs->ARM_cpsr = *ptr;
+ break;
+ default:
+ kgdb_error(KGDBERR_BADPARAMS);
+ break;
+ }
+}
+
+void kgdb_putregs(struct pt_regs *regs, char *buf, int length)
+{
+ unsigned long *kgdb_regs = (unsigned long *)buf;
+
+ if (length != KGDB_ARM_MAX_REGS)
+ kgdb_error(KGDBERR_NOSPACE);
+
+ if ((unsigned long)kgdb_regs & 3)
+ kgdb_error(KGDBERR_ALIGNFAULT);
+
+ regs->ARM_r0 = kgdb_regs[KGDB_ARM_R0];
+ regs->ARM_r1 = kgdb_regs[KGDB_ARM_R1];
+ regs->ARM_r2 = kgdb_regs[KGDB_ARM_R2];
+ regs->ARM_r3 = kgdb_regs[KGDB_ARM_R3];
+ regs->ARM_r4 = kgdb_regs[KGDB_ARM_R4];
+ regs->ARM_r5 = kgdb_regs[KGDB_ARM_R5];
+ regs->ARM_r6 = kgdb_regs[KGDB_ARM_R6];
+ regs->ARM_r7 = kgdb_regs[KGDB_ARM_R7];
+ regs->ARM_r8 = kgdb_regs[KGDB_ARM_R8];
+ regs->ARM_r9 = kgdb_regs[KGDB_ARM_R9];
+ regs->ARM_r10 = kgdb_regs[KGDB_ARM_R10];
+ regs->ARM_ip = kgdb_regs[KGDB_ARM_IP];
+ regs->ARM_fp = kgdb_regs[KGDB_ARM_FP];
+ regs->ARM_sp = kgdb_regs[KGDB_ARM_SP];
+ regs->ARM_lr = kgdb_regs[KGDB_ARM_LR];
+ regs->ARM_pc = kgdb_regs[KGDB_ARM_PC];
+ regs->ARM_cpsr = kgdb_regs[KGDB_ARM_CPSR];
+}
+
+void kgdb_flush_cache_all(void)
+{
+ invalidate_icache_all();
+ flush_dcache_all();
+}
+
+/*
+ * This function will generate a breakpoint exception.
+ * It is used at the beginning of a program to sync up
+ * with a debugger and can be used otherwise as a quick
+ * means to stop program execution and "break" into
+ * the debugger.
+ */
+
+void kgdb_breakpoint(int argc, char * const argv[])
+{
+ asm(".word 0xe7ffdeff");
+}
diff --git a/arch/arm/lib/kgdb/setjmp.S b/arch/arm/lib/kgdb/setjmp.S
new file mode 100644
index 0000000..e17f959
--- /dev/null
+++ b/arch/arm/lib/kgdb/setjmp.S
@@ -0,0 +1,20 @@
+ .text
+ .balign 4
+ .global kgdb_setjmp
+ .type kgdb_setjmp, #function
+kgdb_setjmp:
+ stmia r0, {r4, r5, r6, r7, r8, r9, r10, fp, sp, lr}
+ mov r0, #0
+ mov pc, lr
+ .size kgdb_setjmp,.-kgdb_setjmp
+
+ .text
+ .balign 4
+ .global kgdb_longjmp
+ .type kgdb_longjmp, #function
+kgdb_longjmp:
+ ldmia r0, {r4, r5, r6, r7, r8, r9, r10, fp, sp, lr}
+ movs r0, r1
+ moveq r0, #1
+ mov pc, lr
+ .size kgdb_longjmp,.-kgdb_longjmp
diff --git a/arch/arm/lib/vectors.S b/arch/arm/lib/vectors.S
index 49238ed..8abad3d 100644
--- a/arch/arm/lib/vectors.S
+++ b/arch/arm/lib/vectors.S
@@ -221,15 +221,43 @@ FIQ_STACK_START:
ldr sp, FIQ_STACK_START
.endm
+ .macro get_und_stack
+ get_bad_stack
+ .endm
+
+ .macro und_save_regs
+ bad_save_user_regs
+ .endm
+
+ /* In svc mode */
+ .macro und_restore_regs
+ add r7, sp, #S_PC
+ ldr r6, [r7, #4] @load spsr into r6
+ msr cpsr, r6 @use und spsr to overwrite svc cpsr
+ ldmdb r7, {r1 - r2} @load sp lr into r1 r2
+ mov lr, r2
+ ldmia sp, {r0 - r12}
+ mov r0, r0
+ add sp, sp, #S_FRAME_SIZE
+ ldr pc, [sp, #-12]
+ .endm
+
/*
* exception handlers
*/
.align 5
undefined_instruction:
+#if defined(CONFIG_CMD_KGDB)
+ get_und_stack
+ und_save_regs
+ bl do_undefined_instruction
+ und_restore_regs
+#else
get_bad_stack
bad_save_user_regs
bl do_undefined_instruction
+#endif
.align 5
software_interrupt:
--
1.8.4.5
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