Initial revision

1 files changed, 326 insertions, 0 deletions

diff --git a/lib_ppc/kgdb.c b/lib_ppc/kgdb.c
new file mode 100644
index 0000000..cef35d3
--- /dev/null
+++ b/lib_ppc/kgdb.c
@@ -0,0 +1,326 @@
+#include <common.h>
+#include <command.h>
+
+#if (CONFIG_COMMANDS & CFG_CMD_KGDB)
+
+#include <kgdb.h>
+#include <asm/signal.h>
+#include <asm/processor.h>
+
+#define PC_REGNUM 64
+#define SP_REGNUM 1
+
+void breakinst(void);
+
+int
+kgdb_setjmp(long *buf)
+{
+	asm ("mflr 0; stw 0,0(%0);"
+	     "stw 1,4(%0); stw 2,8(%0);"
+	     "mfcr 0; stw 0,12(%0);"
+	     "stmw 13,16(%0)"
+	     : : "r" (buf));
+	/* XXX should save fp regs as well */
+	return 0;
+}
+
+void
+kgdb_longjmp(long *buf, int val)
+{
+	if (val == 0)
+		val = 1;
+	asm ("lmw 13,16(%0);"
+	     "lwz 0,12(%0); mtcrf 0x38,0;"
+	     "lwz 0,0(%0); lwz 1,4(%0); lwz 2,8(%0);"
+	     "mtlr 0; mr 3,%1"
+	     : : "r" (buf), "r" (val));
+}
+
+static inline unsigned long
+get_msr(void)
+{
+	unsigned long msr;
+	asm volatile("mfmsr %0" : "=r" (msr):);
+	return msr;
+}
+
+static inline void
+set_msr(unsigned long msr)
+{
+	asm volatile("mtmsr %0" : : "r" (msr));
+}
+
+/* Convert the SPARC hardware trap type code to a unix signal number. */
+/*
+ * This table contains the mapping between PowerPC hardware trap types, and
+ * signals, which are primarily what GDB understands.
+ */
+static struct hard_trap_info
+{
+	unsigned int tt;		/* Trap type code for powerpc */
+	unsigned char signo;		/* Signal that we map this trap into */
+} hard_trap_info[] = {
+	{ 0x200, SIGSEGV },			/* machine check */
+	{ 0x300, SIGSEGV },			/* address error (store) */
+	{ 0x400, SIGBUS },			/* instruction bus error */
+	{ 0x500, SIGINT },			/* interrupt */
+	{ 0x600, SIGBUS },			/* alingment */
+	{ 0x700, SIGTRAP },			/* breakpoint trap */
+	{ 0x800, SIGFPE },			/* fpu unavail */
+	{ 0x900, SIGALRM },			/* decrementer */
+	{ 0xa00, SIGILL },			/* reserved */
+	{ 0xb00, SIGILL },			/* reserved */
+	{ 0xc00, SIGCHLD },			/* syscall */
+	{ 0xd00, SIGTRAP },			/* single-step/watch */
+	{ 0xe00, SIGFPE },			/* fp assist */
+	{ 0, 0}				/* Must be last */
+};
+
+static int
+computeSignal(unsigned int tt)
+{
+	struct hard_trap_info *ht;
+
+	for (ht = hard_trap_info; ht->tt && ht->signo; ht++)
+		if (ht->tt == tt)
+			return ht->signo;
+
+	return SIGHUP;         /* default for things we don't know about */
+}
+
+void
+kgdb_enter(struct pt_regs *regs, kgdb_data *kdp)
+{
+	unsigned long msr;
+
+	kdp->private[0] = msr = get_msr();
+	set_msr(msr & ~MSR_EE);	/* disable interrupts */
+
+	if (regs->nip == (unsigned long)breakinst) {
+		/* Skip over breakpoint trap insn */
+		regs->nip += 4;
+	}
+	regs->msr &= ~MSR_SE;
+
+	/* reply to host that an exception has occurred */
+	kdp->sigval = computeSignal(regs->trap);
+
+	kdp->nregs = 2;
+
+	kdp->regs[0].num = PC_REGNUM;
+	kdp->regs[0].val = regs->nip;
+
+	kdp->regs[1].num = SP_REGNUM;
+	kdp->regs[1].val = regs->gpr[SP_REGNUM];
+}
+
+void
+kgdb_exit(struct pt_regs *regs, kgdb_data *kdp)
+{
+	unsigned long msr = kdp->private[0];
+
+	if (kdp->extype & KGDBEXIT_WITHADDR)
+		regs->nip = kdp->exaddr;
+
+	switch (kdp->extype & KGDBEXIT_TYPEMASK) {
+
+	case KGDBEXIT_KILL:
+	case KGDBEXIT_CONTINUE:
+		set_msr(msr);
+		break;
+
+	case KGDBEXIT_SINGLE:
+		regs->msr |= MSR_SE;
+#if 0
+		set_msr(msr | MSR_SE);
+#endif
+		break;
+	}
+}
+
+int
+kgdb_trap(struct pt_regs *regs)
+{
+	return (regs->trap);
+}
+
+/* return the value of the CPU registers.
+ * some of them are non-PowerPC names :(
+ * they are stored in gdb like:
+ * struct {
+ *     u32 gpr[32];
+ *     f64 fpr[32];
+ *     u32 pc, ps, cnd, lr; (ps=msr)
+ *     u32 cnt, xer, mq;
+ * }
+ */
+
+#define SPACE_REQUIRED	((32*4)+(32*8)+(6*4))
+
+#ifdef CONFIG_8260
+/* store floating double indexed */
+#define STFDI(n,p)	__asm__ __volatile__ ("stfd " #n ",%0" : "=o"(p[2*n]))
+/* store floating double multiple */
+#define STFDM(p)	{ STFDI( 0,p); STFDI( 1,p); STFDI( 2,p); STFDI( 3,p); \
+			  STFDI( 4,p); STFDI( 5,p); STFDI( 6,p); STFDI( 7,p); \
+			  STFDI( 8,p); STFDI( 9,p); STFDI(10,p); STFDI(11,p); \
+			  STFDI(12,p); STFDI(13,p); STFDI(14,p); STFDI(15,p); \
+			  STFDI(16,p); STFDI(17,p); STFDI(18,p); STFDI(19,p); \
+			  STFDI(20,p); STFDI(21,p); STFDI(22,p); STFDI(23,p); \
+			  STFDI(24,p); STFDI(25,p); STFDI(26,p); STFDI(27,p); \
+			  STFDI(28,p); STFDI(29,p); STFDI(30,p); STFDI(31,p); }
+#endif
+
+int
+kgdb_getregs(struct pt_regs *regs, char *buf, int max)
+{
+	int i;
+	unsigned long *ptr = (unsigned long *)buf;
+
+	if (max < SPACE_REQUIRED)
+		kgdb_error(KGDBERR_NOSPACE);
+
+	if ((unsigned long)ptr & 3)
+		kgdb_error(KGDBERR_ALIGNFAULT);
+
+	/* General Purpose Regs */
+	for (i = 0; i < 32; i++)
+		*ptr++ = regs->gpr[i];
+
+	/* Floating Point Regs */
+#ifdef CONFIG_8260
+	STFDM(ptr);
+	ptr += 32*2;
+#else
+	for (i = 0; i < 32; i++) {
+		*ptr++ = 0;
+		*ptr++ = 0;
+	}
+#endif
+
+	/* pc, msr, cr, lr, ctr, xer, (mq is unused) */
+	*ptr++ = regs->nip;
+	*ptr++ = regs->msr;
+	*ptr++ = regs->ccr;
+	*ptr++ = regs->link;
+	*ptr++ = regs->ctr;
+	*ptr++ = regs->xer;
+
+	return (SPACE_REQUIRED);
+}
+
+/* set the value of the CPU registers */
+
+#ifdef CONFIG_8260
+/* load floating double */
+#define LFD(n,v)	__asm__ __volatile__ ("lfd " #n ",%0" :: "o"(v))
+/* load floating double indexed */
+#define LFDI(n,p)	__asm__ __volatile__ ("lfd " #n ",%0" :: "o"((p)[2*n]))
+/* load floating double multiple */
+#define LFDM(p)		{ LFDI( 0,p); LFDI( 1,p); LFDI( 2,p); LFDI( 3,p); \
+			  LFDI( 4,p); LFDI( 5,p); LFDI( 6,p); LFDI( 7,p); \
+			  LFDI( 8,p); LFDI( 9,p); LFDI(10,p); LFDI(11,p); \
+			  LFDI(12,p); LFDI(13,p); LFDI(14,p); LFDI(15,p); \
+			  LFDI(16,p); LFDI(17,p); LFDI(18,p); LFDI(19,p); \
+			  LFDI(20,p); LFDI(21,p); LFDI(22,p); LFDI(23,p); \
+			  LFDI(24,p); LFDI(25,p); LFDI(26,p); LFDI(27,p); \
+			  LFDI(28,p); LFDI(29,p); LFDI(30,p); LFDI(31,p); }
+#endif
+
+void
+kgdb_putreg(struct pt_regs *regs, int regno, char *buf, int length)
+{
+	unsigned long *ptr = (unsigned long *)buf;
+
+	if (regno < 0 || regno >= 70)
+		kgdb_error(KGDBERR_BADPARAMS);
+	else if (regno >= 32 && regno < 64) {
+		if (length < 8)
+			kgdb_error(KGDBERR_NOSPACE);
+	}
+	else {
+		if (length < 4)
+			kgdb_error(KGDBERR_NOSPACE);
+	}
+
+	if ((unsigned long)ptr & 3)
+		kgdb_error(KGDBERR_ALIGNFAULT);
+
+	if (regno >= 0 && regno < 32)
+		regs->gpr[regno] = *ptr;
+	else switch (regno) {
+
+#ifdef CONFIG_8260
+#define caseF(n) \
+	case (n) + 32:	LFD(n, *ptr);		break;
+
+caseF( 0) caseF( 1) caseF( 2) caseF( 3) caseF( 4) caseF( 5) caseF( 6) caseF( 7)
+caseF( 8) caseF( 9) caseF(10) caseF(11) caseF(12) caseF(13) caseF(14) caseF(15)
+caseF(16) caseF(17) caseF(18) caseF(19) caseF(20) caseF(21) caseF(22) caseF(23)
+caseF(24) caseF(25) caseF(26) caseF(27) caseF(28) caseF(29) caseF(30) caseF(31)
+
+#undef caseF
+#endif
+
+	case 64:	regs->nip = *ptr;	break;
+	case 65:	regs->msr = *ptr;	break;
+	case 66:	regs->ccr = *ptr;	break;
+	case 67:	regs->link = *ptr;	break;
+	case 68:	regs->ctr = *ptr;	break;
+	case 69:	regs->ctr = *ptr;	break;
+
+	default:
+		kgdb_error(KGDBERR_BADPARAMS);
+	}
+}
+
+void
+kgdb_putregs(struct pt_regs *regs, char *buf, int length)
+{
+	int i;
+	unsigned long *ptr = (unsigned long *)buf;
+
+	if (length < SPACE_REQUIRED)
+		kgdb_error(KGDBERR_NOSPACE);
+
+	if ((unsigned long)ptr & 3)
+		kgdb_error(KGDBERR_ALIGNFAULT);
+
+	/*
+	 * If the stack pointer has moved, you should pray.
+	 * (cause only god can help you).
+	 */
+
+	/* General Purpose Regs */
+	for (i = 0; i < 32; i++)
+		regs->gpr[i] = *ptr++;
+
+	/* Floating Point Regs */
+#ifdef CONFIG_8260
+	LFDM(ptr);
+#endif
+	ptr += 32*2;
+
+	/* pc, msr, cr, lr, ctr, xer, (mq is unused) */
+	regs->nip = *ptr++;
+	regs->msr = *ptr++;
+	regs->ccr = *ptr++;
+	regs->link = *ptr++;
+	regs->ctr = *ptr++;
+	regs->xer = *ptr++;
+}
+
+/* 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[])
+{
+	asm("	.globl breakinst\n\
+	     breakinst: .long 0x7d821008\n\
+            ");
+}
+
+#endif /* CFG_CMD_KGDB */