Add kernel support for debugging with gdb. This also make /proc allow

access to the registers. The format of the registers returned in ptrace,
/proc and in the coredump header match what gdb was expecting.
Floating point registers are not yet copied into the structure.
The location of the fpr needs to be found and copied. <- TODO

Changes to trap.c was to add some interm debugging. code is commented out.

powerpc does not currently have a MID_* type, since it uses ELF instead
of a.out, one was never added. Currently the coredump is done in form
of MID_NONE. What is the correct approach for this?? Elf format coredumps...
maybe?

6 files changed, 108 insertions, 16 deletions

diff --git a/sys/arch/powerpc/include/pcb.h b/sys/arch/powerpc/include/pcb.h
index ab02043c45f..ea32d4bbcab 100644
--- a/sys/arch/powerpc/include/pcb.h
+++ b/sys/arch/powerpc/include/pcb.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pcb.h,v 1.2 1996/12/28 06:25:18 rahnds Exp $	*/
+/*	$OpenBSD: pcb.h,v 1.3 1998/08/07 02:22:03 rahnds Exp $	*/
 /*	$NetBSD: pcb.h,v 1.1 1996/09/30 16:34:29 ws Exp $	*/
 
 /*-
@@ -34,6 +34,7 @@
 #ifndef	_MACHINE_PCB_H_
 #define	_MACHINE_PCB_H_
 
+#include <machine/reg.h>
 typedef int faultbuf[24];
 
 struct pcb {
@@ -51,8 +52,7 @@ struct pcb {
 };
 
 struct md_coredump {
-	struct trapframe frame;
-	/* Need to add FPU regs here */
+	struct reg regs;
 };
 
 #ifdef	_KERNEL
diff --git a/sys/arch/powerpc/include/ptrace.h b/sys/arch/powerpc/include/ptrace.h
index 321320297e6..7190d31d4a2 100644
--- a/sys/arch/powerpc/include/ptrace.h
+++ b/sys/arch/powerpc/include/ptrace.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ptrace.h,v 1.1 1996/12/28 06:09:22 rahnds Exp $	*/
+/*	$OpenBSD: ptrace.h,v 1.2 1998/08/07 02:22:05 rahnds Exp $	*/
 /*	$NetBSD: ptrace.h,v 1.7 1995/01/26 19:47:10 mycroft Exp $	*/
 
 /*
@@ -37,10 +37,10 @@
  * powerpc-dependent ptrace definitions
  */
 #define	PT_STEP		(PT_FIRSTMACH + 0)
-#if NOT_SUPPORTED
 #define	PT_GETREGS	(PT_FIRSTMACH + 1)
 #define	PT_SETREGS	(PT_FIRSTMACH + 2)
 
+#if NOT_SUPPORTED
 #define	PT_GETFPREGS	(PT_FIRSTMACH + 3)
 #define	PT_SETFPREGS	(PT_FIRSTMACH + 4)
 #endif
diff --git a/sys/arch/powerpc/include/reg.h b/sys/arch/powerpc/include/reg.h
index b0c31944803..ba2ab6413a9 100644
--- a/sys/arch/powerpc/include/reg.h
+++ b/sys/arch/powerpc/include/reg.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: reg.h,v 1.1 1997/01/02 02:55:47 rahnds Exp $	*/
+/*	$OpenBSD: reg.h,v 1.2 1998/08/07 02:22:06 rahnds Exp $	*/
 
 /*-
  * Copyright (c) 1990 The Regents of the University of California.
@@ -41,5 +41,22 @@
 #ifndef _POWERPC_REG_H_
 #define _POWERPC_REG_H_
 
-/* not supported yet */
+/*
+ * Struct reg, used for procfs and in signal contexts
+ * Note that in signal contexts, it's represented as an array.
+ * That array has to look exactly like 'struct reg' though.
+ */
+
+/* this table is set up to match what gdb expects */
+struct reg {
+	u_int32_t gpr[32];
+	u_int64_t fpr[32];
+	u_int32_t pc;
+	u_int32_t ps;
+	u_int32_t cnd;
+	u_int32_t lr;
+	u_int32_t cnt;
+	u_int32_t xer;
+	u_int32_t mq;
+};
 #endif /* !_POWERPC_REG_H_ */
diff --git a/sys/arch/powerpc/powerpc/process_machdep.c b/sys/arch/powerpc/powerpc/process_machdep.c
index 1bb3b9ebb60..99ade0ecc9f 100644
--- a/sys/arch/powerpc/powerpc/process_machdep.c
+++ b/sys/arch/powerpc/powerpc/process_machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: process_machdep.c,v 1.2 1996/12/28 06:22:16 rahnds Exp $	*/
+/*	$OpenBSD: process_machdep.c,v 1.3 1998/08/07 02:22:08 rahnds Exp $	*/
 /*	$NetBSD: process_machdep.c,v 1.1 1996/09/30 16:34:53 ws Exp $	*/
 
 /*
@@ -33,6 +33,7 @@
  */
 #include <sys/param.h>
 #include <sys/proc.h>
+#include <machine/reg.h>
 
 /*
  * Set the process's program counter.
@@ -61,3 +62,46 @@ process_sstep(p, sstep)
 		tf->srr1 &= ~PSL_SE;
 	return 0;
 }
+int
+process_read_regs(p, regs)
+	struct proc *p;
+	struct reg *regs;
+{
+	struct trapframe *tf = trapframe(p);
+
+	bcopy(&(tf->fixreg[0]), &(regs->gpr[0]), sizeof(regs->gpr));
+	bzero(&(regs->fpr[0]), sizeof(regs->fpr));
+	/* 
+	 * need to do floating point here
+	 */
+	regs->pc  = tf->srr0;
+	regs->ps  = tf->srr1; /* is this the correct value for this ? */
+	regs->cnd = tf->cr;
+	regs->lr  = tf->lr;
+	regs->cnt = tf->ctr;
+	regs->xer = tf->xer;
+	regs->mq  = 0; /*  what should this really be? */
+
+	return (0);
+}
+int
+process_write_regs(p, regs)
+	struct proc *p;
+	struct reg *regs;
+{
+	struct trapframe *tf = trapframe(p);
+
+	bcopy(&(regs->gpr[0]), &(tf->fixreg[0]), sizeof(regs->gpr));
+	/* 
+	 * need to do floating point here
+	 */
+	tf->srr0 = regs->pc;
+	tf->srr1 = regs->ps;  /* is this the correct value for this ? */
+	tf->cr   = regs->cnd;
+	tf->lr   = regs->lr;
+	tf->ctr  = regs->cnt;
+	tf->xer  = regs->xer;
+	/*  regs->mq = 0; what should this really be? */
+
+	return (0);
+}
diff --git a/sys/arch/powerpc/powerpc/trap.c b/sys/arch/powerpc/powerpc/trap.c
index e95f96b49e9..c88c18ac34b 100644
--- a/sys/arch/powerpc/powerpc/trap.c
+++ b/sys/arch/powerpc/powerpc/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.8 1998/05/29 04:15:41 rahnds Exp $	*/
+/*	$OpenBSD: trap.c,v 1.9 1998/08/07 02:22:09 rahnds Exp $	*/
 /*	$NetBSD: trap.c,v 1.3 1996/10/13 03:31:37 christos Exp $	*/
 
 /*
@@ -56,6 +56,34 @@
 
 volatile int want_resched;
 
+#ifdef PPC_WANT_BACKTRACE
+void dumpframe (u_int32_t pframe)
+{
+	u_int32_t nextframe;
+	u_int32_t lr;
+	int error;
+	if (error = copyin ((void *)pframe, &nextframe , 4) ){
+		printf("unable to read next frame @%x\n", pframe);
+		return;
+	}
+	if (error = copyin ((void *)(pframe+4), &lr , 4) ){
+		printf("unable to read lr @%x\n", pframe+4);
+		return;
+	}
+	printf("lr %x fp %x nfp %x\n", lr, pframe, nextframe);
+
+	if (nextframe != 0) {
+		dumpframe(nextframe);
+	}
+	return;
+}
+void
+ppc_dumpbt(struct trapframe *frame)
+{
+	dumpframe(frame->fixreg[1]);
+	return;
+}
+#endif
 void
 trap(frame)
 	struct trapframe *frame;
@@ -123,7 +151,11 @@ printf("kern dsi on addr %x iar %x\n", frame->dar, frame->srr0);
 				     trunc_page(frame->dar), ftype, FALSE)
 			    == KERN_SUCCESS)
 				break;
-printf("dsi on addr %x iar %x\n", frame->dar, frame->srr0);
+printf("dsi on addr %x iar %x lr %x\n", frame->dar, frame->srr0,frame->lr);
+/*
+ * keep this for later in case we want it later.
+ppc_dumpbt(frame);
+*/
 			sv.sival_int = frame->dar;
 			trapsignal(p, SIGSEGV, vftype, SEGV_MAPERR, sv);
 		}
diff --git a/sys/arch/powerpc/powerpc/vm_machdep.c b/sys/arch/powerpc/powerpc/vm_machdep.c
index b9ca7a1690b..5739a2295db 100644
--- a/sys/arch/powerpc/powerpc/vm_machdep.c
+++ b/sys/arch/powerpc/powerpc/vm_machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vm_machdep.c,v 1.3 1997/10/13 13:43:02 pefo Exp $	*/
+/*	$OpenBSD: vm_machdep.c,v 1.4 1998/08/07 02:22:10 rahnds Exp $	*/
 /*	$NetBSD: vm_machdep.c,v 1.1 1996/09/30 16:34:57 ws Exp $	*/
 
 /*
@@ -180,16 +180,15 @@ cpu_coredump(p, vp, cred, chdr)
 	struct trapframe *tf;
 	int error;
 	
-#if 0
-	CORE_SETMAGIC(*chdr, COREMAGIC, MID_POWERPC, 0);
+#if 1
+	CORE_SETMAGIC(*chdr, COREMAGIC, MID_ZERO, 0);
 	chdr->c_hdrsize = ALIGN(sizeof *chdr);
 	chdr->c_seghdrsize = ALIGN(sizeof cseg);
 	chdr->c_cpusize = sizeof md_core;
 
-	tf = trapframe(p);
-	bcopy(tf, &md_core.frame, sizeof md_core.frame);
+	process_read_regs(p, &md_core);
 	
-	CORE_SETMAGIC(cseg, CORESEGMAGIC, MID_POWERPC, CORE_CPU);
+	CORE_SETMAGIC(cseg, CORESEGMAGIC, MID_ZERO, CORE_CPU);
 	cseg.c_addr = 0;
 	cseg.c_size = chdr->c_cpusize;