[U-Boot] [PATCH v2 3/4] [ARM] Add KGDB support for ARM platforms
Tonny Tzeng
tonny.tzeng at gmail.com
Sat Apr 17 20:16:51 CEST 2010
Signed-off-by: Tonny Tzeng <tonny.tzeng at gmail.com>
---
arch/arm/include/asm/kgdb.h | 66 +++++++++++++++
arch/arm/lib/Makefile | 1 +
arch/arm/lib/kgdb.c | 194 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 261 insertions(+), 0 deletions(-)
create mode 100644 arch/arm/include/asm/kgdb.h
create mode 100644 arch/arm/lib/kgdb.c
diff --git a/arch/arm/include/asm/kgdb.h b/arch/arm/include/asm/kgdb.h
new file mode 100644
index 0000000..dfca31c
--- /dev/null
+++ b/arch/arm/include/asm/kgdb.h
@@ -0,0 +1,66 @@
+/*
+ * ARM KGDB support
+ *
+ * Author: Deepak Saxena <dsaxena at mvista.com>
+ *
+ * Copyright (C) 2002 MontaVista Software Inc.
+ *
+ */
+#ifndef __ARM_KGDB_H__
+#define __ARM_KGDB_H__
+
+#define BREAK_INSTR_SIZE 4
+#define KGDB_COMPILED_BREAK 0xe7ffdeff
+
+#ifndef __ASSEMBLY__
+
+static inline void arch_kgdb_breakpoint(void)
+{
+ asm(".word 0xe7ffdeff");
+}
+
+#endif /* !__ASSEMBLY__ */
+
+/*
+ * From Kevin Hilman:
+ *
+ * gdb is expecting the following registers layout.
+ *
+ * r0-r15: 1 long word each
+ * f0-f7: unused, 3 long words each !!
+ * fps: unused, 1 long word
+ * cpsr: 1 long word
+ *
+ * Even though f0-f7 and fps are not used, they need to be
+ * present in the registers sent for correct processing in
+ * the host-side gdb.
+ *
+ * In particular, it is crucial that CPSR is in the right place,
+ * otherwise gdb will not be able to correctly interpret stepping over
+ * conditional branches.
+ */
+#define _GP_REGS 16
+#define _FP_REGS 8
+#define _EXTRA_REGS 2
+#define GDB_MAX_REGS (_GP_REGS + (_FP_REGS * 3) + _EXTRA_REGS)
+
+#define _R0 0
+#define _R1 1
+#define _R2 2
+#define _R3 3
+#define _R4 4
+#define _R5 5
+#define _R6 6
+#define _R7 7
+#define _R8 8
+#define _R9 9
+#define _R10 10
+#define _FP 11
+#define _IP 12
+#define _SPT 13
+#define _LR 14
+#define _PC 15
+#define _CPSR (GDB_MAX_REGS - 1)
+
+#endif /* __ASM_KGDB_H__ */
+
diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile
index 0293348..36fe528 100644
--- a/arch/arm/lib/Makefile
+++ b/arch/arm/lib/Makefile
@@ -44,6 +44,7 @@ COBJS-y += cache-cp15.o
endif
COBJS-y += interrupts.o
COBJS-y += reset.o
+COBJS-$(CONFIG_CMD_KGDB) += kgdb.o
SRCS := $(GLSOBJS:.o=.S) $(GLCOBJS:.o=.c) \
$(SOBJS-y:.o=.S) $(COBJS-y:.o=.c)
diff --git a/arch/arm/lib/kgdb.c b/arch/arm/lib/kgdb.c
new file mode 100644
index 0000000..f7044f6
--- /dev/null
+++ b/arch/arm/lib/kgdb.c
@@ -0,0 +1,194 @@
+#include <common.h>
+#include <asm-generic/signal.h>
+#include <kgdb.h>
+
+/*
+ * kgdb_breakpoint - generate breakpoint exception
+ *
+ * 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 *argv[])
+{
+ arch_kgdb_breakpoint();
+}
+
+int kgdb_setjmp(long *buf)
+{
+ asm(" stmia r0, {r0-r14}\n \
+ str lr,[r0, #60]\n \
+ mrs r1,cpsr\n \
+ str r1,[r0,#64]\n \
+ ldr r1,[r0,#4]\n \
+ ");
+ return 0;
+}
+
+void kgdb_longjmp(long *buf, int val)
+{
+ asm(" str r1,[r0]\n \
+ ldr r1,[r0, #64]\n \
+ msr spsr,r1\n \
+ ldmia r0,{r0-pc}^\n \
+ ");
+}
+
+int kgdb_trap(struct pt_regs *regs)
+{
+ return SIGTRAP;
+}
+
+void kgdb_enter(struct pt_regs *regs, kgdb_data *kdp)
+{
+ kdp->sigval = kgdb_trap(regs);
+ kdp->nregs = 0;
+}
+
+void kgdb_exit(struct pt_regs *regs, kgdb_data *kdp)
+{
+}
+
+int kgdb_getregs(struct pt_regs *regs, char *buf, int max)
+{
+ int i;
+ unsigned long *gdb_regs = (unsigned long *)buf;
+
+ if (max < (GDB_MAX_REGS * sizeof(unsigned long)))
+ kgdb_error(KGDBERR_NOSPACE);
+
+ /* Initialize all to zero. */
+ for (i = 0; i < GDB_MAX_REGS; i++)
+ gdb_regs[i] = 0;
+
+ gdb_regs[_R0] = regs->ARM_r0;
+ gdb_regs[_R1] = regs->ARM_r1;
+ gdb_regs[_R2] = regs->ARM_r2;
+ gdb_regs[_R3] = regs->ARM_r3;
+ gdb_regs[_R4] = regs->ARM_r4;
+ gdb_regs[_R5] = regs->ARM_r5;
+ gdb_regs[_R6] = regs->ARM_r6;
+ gdb_regs[_R7] = regs->ARM_r7;
+ gdb_regs[_R8] = regs->ARM_r8;
+ gdb_regs[_R9] = regs->ARM_r9;
+ gdb_regs[_R10] = regs->ARM_r10;
+ gdb_regs[_FP] = regs->ARM_fp;
+ gdb_regs[_IP] = regs->ARM_ip;
+ gdb_regs[_SPT] = regs->ARM_sp;
+ gdb_regs[_LR] = regs->ARM_lr;
+ gdb_regs[_PC] = regs->ARM_pc;
+ gdb_regs[_CPSR] = regs->ARM_cpsr;
+
+ return GDB_MAX_REGS *sizeof(unsigned long);
+}
+
+void kgdb_putreg(struct pt_regs *regs, int regno, char *buf, int length)
+{
+ unsigned long val, *ptr = (unsigned long *)buf;
+
+ if (regno < 0 || GDB_MAX_REGS <= regno)
+ kgdb_error(KGDBERR_BADPARAMS);
+ else {
+ if (length < 4)
+ kgdb_error(KGDBERR_NOSPACE);
+ }
+ if ((unsigned long)ptr & 3)
+ kgdb_error(KGDBERR_ALIGNFAULT);
+ else
+ val = *ptr;
+
+ switch (regno) {
+ case _R0:
+ regs->ARM_r0 = val; break;
+ case _R1:
+ regs->ARM_r1 = val; break;
+ case _R2:
+ regs->ARM_r2 = val; break;
+ case _R3:
+ regs->ARM_r3 = val; break;
+ case _R4:
+ regs->ARM_r4 = val; break;
+ case _R5:
+ regs->ARM_r5 = val; break;
+ case _R6:
+ regs->ARM_r6 = val; break;
+ case _R7:
+ regs->ARM_r7 = val; break;
+ case _R8:
+ regs->ARM_r8 = val; break;
+ case _R9:
+ regs->ARM_r9 = val; break;
+ case _R10:
+ regs->ARM_r10 = val; break;
+ case _FP:
+ regs->ARM_fp = val; break;
+ case _IP:
+ regs->ARM_ip = val; break;
+ case _SPT:
+ regs->ARM_sp = val; break;
+ case _LR:
+ regs->ARM_lr = val; break;
+ case _PC:
+ regs->ARM_pc = val; break;
+ case 0x19:
+ regs->ARM_cpsr = val; break;
+ default:
+ kgdb_error(KGDBERR_BADPARAMS);
+ }
+}
+
+void kgdb_putregs(struct pt_regs *regs, char *buf, int length)
+{
+ unsigned long *gdb_regs = (unsigned long *)buf;
+
+ if (length < (GDB_MAX_REGS *sizeof(unsigned long)))
+ kgdb_error(KGDBERR_NOSPACE);
+
+ if ((unsigned long)gdb_regs & 3)
+ kgdb_error(KGDBERR_ALIGNFAULT);
+
+ regs->ARM_r0 = gdb_regs[_R0];
+ regs->ARM_r1 = gdb_regs[_R1];
+ regs->ARM_r2 = gdb_regs[_R2];
+ regs->ARM_r3 = gdb_regs[_R3];
+ regs->ARM_r4 = gdb_regs[_R4];
+ regs->ARM_r5 = gdb_regs[_R5];
+ regs->ARM_r6 = gdb_regs[_R6];
+ regs->ARM_r7 = gdb_regs[_R7];
+ regs->ARM_r8 = gdb_regs[_R8];
+ regs->ARM_r9 = gdb_regs[_R9];
+ regs->ARM_r10 = gdb_regs[_R10];
+ regs->ARM_fp = gdb_regs[_FP];
+ regs->ARM_ip = gdb_regs[_IP];
+ regs->ARM_sp = gdb_regs[_SPT];
+ regs->ARM_lr = gdb_regs[_LR];
+ regs->ARM_pc = gdb_regs[_PC];
+ regs->ARM_cpsr = gdb_regs[_CPSR];
+}
+
+void kgdb_interruptible(int yes)
+{
+#ifdef CONFIG_USE_IRQ
+ if (yes)
+ enable_interrupts();
+ else
+ disable_interrupts();
+#endif
+}
+
+void arch_kgdb_set_sw_break(struct kgdb_bkpt *bkpt)
+{
+ int addr = bkpt->bpt_addr;
+ memcpy(bkpt->saved_instr, (unsigned long *)addr, BREAK_INSTR_SIZE);
+ *(unsigned long *)addr = KGDB_COMPILED_BREAK;
+ kgdb_flush_cache_all();
+}
+
+void arch_kgdb_remove_sw_break(struct kgdb_bkpt *bkpt)
+{
+ int addr = bkpt->bpt_addr;
+ memcpy((unsigned long *)addr, bkpt->saved_instr, BREAK_INSTR_SIZE);
+ kgdb_flush_cache_all();
+}
+
--
1.6.0.6
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