Enter ddb at a trap instruction or with db_enter().

Tell make that trap_subr.S needs assym.h.
Fill in opal_cngetc() so I can type at the "ddb>" prompt.
Add enough code to trap_subr.S to "c" continue from ddb.
Give registers to ddb.
Try to load symbols from initrd.

ok kettenis@

12 files changed, 355 insertions, 31 deletions

diff --git a/sys/arch/powerpc64/conf/Makefile.powerpc64 b/sys/arch/powerpc64/conf/Makefile.powerpc64
index 7c339bc98fa..05a5ac38ade 100644
--- a/sys/arch/powerpc64/conf/Makefile.powerpc64
+++ b/sys/arch/powerpc64/conf/Makefile.powerpc64
@@ -1,4 +1,4 @@
-#	$OpenBSD: Makefile.powerpc64,v 1.1 2020/05/16 17:11:14 kettenis Exp $
+#	$OpenBSD: Makefile.powerpc64,v 1.2 2020/05/27 22:22:04 gkoehler Exp $
 
 # For instructions on building kernels consult the config(8) and options(4)
 # manual pages.
@@ -161,6 +161,8 @@ depend obj:
 
 locore0.o: ${_machdir}/${_mach}/locore0.S assym.h
 
+trap_subr.o: ${_machdir}/${_mach}/trap_subr.S assym.h
+
 hardlink-obsd:
 	[[ ! -f /bsd ]] || cmp -s bsd /bsd || ln -f /bsd /obsd
 
diff --git a/sys/arch/powerpc64/conf/files.powerpc64 b/sys/arch/powerpc64/conf/files.powerpc64
index 04585908d67..0140d746404 100644
--- a/sys/arch/powerpc64/conf/files.powerpc64
+++ b/sys/arch/powerpc64/conf/files.powerpc64
@@ -1,4 +1,4 @@
-# $OpenBSD: files.powerpc64,v 1.3 2020/05/22 15:07:46 kettenis Exp $
+# $OpenBSD: files.powerpc64,v 1.4 2020/05/27 22:22:04 gkoehler Exp $
 
 maxpartitions	16
 maxusers	2 8 128
@@ -19,6 +19,7 @@ file	arch/powerpc64/powerpc64/autoconf.c
 file	arch/powerpc64/powerpc64/conf.c
 file	arch/powerpc64/powerpc64/cpu.c
 file	arch/powerpc64/powerpc64/db_disasm.c		ddb
+file	arch/powerpc64/powerpc64/db_interface.c		ddb
 file	arch/powerpc64/powerpc64/db_memrw.c		ddb
 file	arch/powerpc64/powerpc64/db_trace.c		ddb
 file	arch/powerpc64/powerpc64/disksubr.c
diff --git a/sys/arch/powerpc64/include/_types.h b/sys/arch/powerpc64/include/_types.h
index bc2cc00c0d5..c93d8b0d84e 100644
--- a/sys/arch/powerpc64/include/_types.h
+++ b/sys/arch/powerpc64/include/_types.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: _types.h,v 1.1 2020/05/16 17:11:14 kettenis Exp $ */
+/* $OpenBSD: _types.h,v 1.2 2020/05/27 22:22:04 gkoehler Exp $ */
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -36,7 +36,7 @@
 
 #if defined(_KERNEL)
 typedef struct label_t {
-	long val[13];
+	long val[22];
 } label_t;
 #endif
 
diff --git a/sys/arch/powerpc64/include/db_machdep.h b/sys/arch/powerpc64/include/db_machdep.h
index 29005daa76a..1b823b3ea02 100644
--- a/sys/arch/powerpc64/include/db_machdep.h
+++ b/sys/arch/powerpc64/include/db_machdep.h
@@ -1,25 +1,80 @@
-typedef long		db_expr_t;
+/*	$OpenBSD: db_machdep.h,v 1.3 2020/05/27 22:22:04 gkoehler Exp $*/
+/*	$NetBSD: db_machdep.h,v 1.13 1996/04/29 20:50:08 leo Exp $	*/
 
-typedef long		db_regs_t;
+/*
+ * Mach Operating System
+ * Copyright (c) 1992 Carnegie Mellon University
+ * All Rights Reserved.
+ *
+ * Permission to use, copy, modify and distribute this software and its
+ * documentation is hereby granted, provided that both the copyright
+ * notice and this permission notice appear in all copies of the
+ * software, derivative works or modified versions, and any portions
+ * thereof, and that both notices appear in supporting documentation.
+ *
+ * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
+ * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
+ * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ *
+ * Carnegie Mellon requests users of this software to return to
+ *
+ *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
+ *  School of Computer Science
+ *  Carnegie Mellon University
+ *  Pittsburgh PA 15213-3890
+ *
+ * any improvements or extensions that they make and grant Carnegie Mellon
+ * the rights to redistribute these changes.
+ */
 
-extern db_regs_t	ddb_regs;
+/*
+ * Machine-dependent defines for new kernel debugger.
+ */
+#ifndef _MACHINE_DB_MACHDEP_H_
+#define _MACHINE_DB_MACHDEP_H_
 
-#define PC_REGS(regs)	(*regs)
+#include <sys/types.h>
+#include <uvm/uvm_param.h>
+#include <machine/trap.h>
 
-#define BKPT_SIZE	4
-#define BKPT_SET(inst)	0xdeadbeef
+typedef vaddr_t	db_addr_t;	/* address - unsigned */
+typedef long		db_expr_t;	/* expression - signed */
+typedef struct trapframe db_regs_t;
+extern db_regs_t ddb_regs;		/* register state */
 
-#define db_clear_single_step(regs)	(0)
-#define db_set_single_step(regs)	(0)
+#define PC_REGS(regs)	((regs)->srr0)
+#define SET_PC_REGS(regs, value)	PC_REGS(regs) = (value)
 
-#define IS_BREAKPOINT_TRAP(type, code)	(0)
-#define IS_WATCHPOINT_TRAP(type, code)	(0)
+#define BKPT_INST	0x7C810808	/* breakpoint instruction */
 
-// ALL BROKEN!!!
-#define	inst_trap_return(ins)	((ins) == 0 && (ins) == 1)
-#define	inst_return(ins)	((ins) == 0 && (ins) == 1)
-				
-#define	inst_call(ins)		((ins) == 0 && (ins) == 1)
-#define	inst_branch(ins)	((ins) == 0 && (ins) == 1)
-#define inst_unconditional_flow_transfer(ins)	(0)
+#define BKPT_SIZE	(4)		/* size of breakpoint inst */
+#define BKPT_SET(inst)	(BKPT_INST)
 
+#define FIXUP_PC_AFTER_BREAK(regs)	((regs)->srr0 -= 4)
+
+#define SR_SINGLESTEP 0x8000
+#define db_clear_single_step(regs)	((regs)->srr1 &= ~SR_SINGLESTEP)
+#define db_set_single_step(regs)	((regs)->srr1 |=  SR_SINGLESTEP)
+
+#define T_BREAKPOINT	0xffff
+#define IS_BREAKPOINT_TRAP(type, code)	((type) == T_BREAKPOINT)
+#define IS_WATCHPOINT_TRAP(type, code)	0
+
+#define M_RTS		0xfc0007fe
+#define I_RTS		0x4c000020
+#define M_BC		0xfc000000
+#define I_BC		0x40000000
+#define M_B		0xfc000000
+#define I_B		0x50000000
+#define M_RFI		0xfc0007fe
+#define I_RFI		0x4c000064
+
+#define inst_trap_return(ins)	(((ins)&M_RFI) == I_RFI)
+#define inst_return(ins)	(((ins)&M_RTS) == I_RTS)
+#define inst_call(ins)		(((ins)&M_BC ) == I_BC  || \
+				 ((ins)&M_B  ) == I_B )
+
+struct trapframe;
+void db_ktrap(int, db_regs_t *);
+
+#endif /* _MACHINE_DB_MACHDEP_H_ */
diff --git a/sys/arch/powerpc64/include/exec.h b/sys/arch/powerpc64/include/exec.h
index a65ac47da72..f85c8361bcf 100644
--- a/sys/arch/powerpc64/include/exec.h
+++ b/sys/arch/powerpc64/include/exec.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: exec.h,v 1.1 2020/05/16 17:11:14 kettenis Exp $ */
+/* $OpenBSD: exec.h,v 1.2 2020/05/27 22:22:04 gkoehler Exp $ */
 
 /*
  * Copyright (c) 2014 Patrick Wildt <patrick@blueri.se>
@@ -24,7 +24,7 @@
 #define ARCH_ELFSIZE		64
 
 #define ELF_TARG_CLASS		ELFCLASS64
-#define ELF_TARG_DATA		ELFDATA2LSB
-#define ELF_TARG_MACH		EM_AARCH64
+#define ELF_TARG_DATA		ELFDATA2MSB
+#define ELF_TARG_MACH		EM_PPC64
 
 #endif
diff --git a/sys/arch/powerpc64/include/opal.h b/sys/arch/powerpc64/include/opal.h
index 4cce8a2c18a..886cce8d8e2 100644
--- a/sys/arch/powerpc64/include/opal.h
+++ b/sys/arch/powerpc64/include/opal.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: opal.h,v 1.1 2020/05/23 11:40:16 kettenis Exp $	*/
+/*	$OpenBSD: opal.h,v 1.2 2020/05/27 22:22:04 gkoehler Exp $	*/
 
 /*
  * Copyright (c) 2020 Mark Kettenis <kettenis@openbsd.org>
@@ -21,14 +21,18 @@
 
 #define OPAL_TEST		0
 #define OPAL_CONSOLE_WRITE	1
+#define OPAL_CONSOLE_READ	2
 #define OPAL_CEC_POWER_DOWN	5
 #define OPAL_CEC_REBOOT		6
+#define OPAL_POLL_EVENTS	10
 
 #ifndef _LOCORE
 int64_t	opal_test(uint64_t);
 int64_t	opal_console_write(int64_t, int64_t *, const uint8_t *);
+int64_t	opal_console_read(int64_t, int64_t *, uint8_t *);
 int64_t	opal_cec_power_down(uint64_t);
 int64_t	opal_cec_reboot(void);
+int64_t	opal_poll_events(uint64_t *);
 
 void	opal_printf(const char *fmt, ...);
 #endif
diff --git a/sys/arch/powerpc64/powerpc64/db_interface.c b/sys/arch/powerpc64/powerpc64/db_interface.c
new file mode 100644
index 00000000000..02df878b041
--- /dev/null
+++ b/sys/arch/powerpc64/powerpc64/db_interface.c
@@ -0,0 +1,104 @@
+/*	$OpenBSD: db_interface.c,v 1.1 2020/05/27 22:22:04 gkoehler Exp $	*/
+/*      $NetBSD: db_interface.c,v 1.12 2001/07/22 11:29:46 wiz Exp $ */
+
+/*
+ * Mach Operating System
+ * Copyright (c) 1991,1990 Carnegie Mellon University
+ * All Rights Reserved.
+ *
+ * Permission to use, copy, modify and distribute this software and its
+ * documentation is hereby granted, provided that both the copyright
+ * notice and this permission notice appear in all copies of the
+ * software, derivative works or modified versions, and any portions
+ * thereof, and that both notices appear in supporting documentation.
+ *
+ * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
+ * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
+ * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ *
+ * Carnegie Mellon requests users of this software to return to
+ *
+ *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
+ *  School of Computer Science
+ *  Carnegie Mellon University
+ *  Pittsburgh PA 15213-3890
+ *
+ * any improvements or extensions that they make and grant Carnegie the
+ * rights to redistribute these changes.
+ *
+ *      db_interface.c,v 2.4 1991/02/05 17:11:13 mrt (CMU)
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+
+#include <dev/cons.h>
+#include <dev/ofw/fdt.h>
+
+#include <machine/db_machdep.h>
+#include <ddb/db_elf.h>
+#include <ddb/db_extern.h>
+#include <ddb/db_sym.h>
+
+extern db_regs_t ddb_regs; /* db_trace.c */
+extern db_symtab_t db_symtab; /* ddb/db_elf.c */
+extern struct fdt_reg initrd_reg; /* machdep.c */
+
+void
+db_machine_init(void)
+{
+	db_expr_t val;
+	uint64_t a, b;
+	char *prop_start, *prop_end;
+	void *node;
+
+	/*
+	 * petitboot loads the kernel without symbols.
+	 * If an initrd exists, try to load symbols from there.
+	 */
+	node = fdt_find_node("/chosen");
+	if (fdt_node_property(node, "linux,initrd-start", &prop_start) != 8 &&
+	    fdt_node_property(node, "linux,initrd-end", &prop_end) != 8) {
+		printf("[ no initrd ]\n");
+		return;
+	}
+
+	a = bemtoh64((uint64_t *)prop_start);
+	b = bemtoh64((uint64_t *)prop_end);
+	initrd_reg.addr = trunc_page(a);
+	initrd_reg.size = round_page(b) - initrd_reg.addr;
+	db_elf_sym_init(b - a, (char *)a, (char *)b, "initrd");
+
+	/* The kernel is PIE. Add an offset to most symbols. */
+	if (db_symbol_by_name("db_machine_init", &val) != NULL) {
+		Elf_Sym *symp, *symtab_start, *symtab_end;
+		Elf_Addr offset;
+		
+		symtab_start = STAB_TO_SYMSTART(&db_symtab);
+		symtab_end = STAB_TO_SYMEND(&db_symtab);
+		
+		offset = (Elf_Addr)db_machine_init - (Elf_Addr)val;
+		for (symp = symtab_start; symp < symtab_end; symp++) {
+			if (symp->st_shndx != SHN_ABS)
+				symp->st_value += offset;
+		}
+	}
+}
+
+void
+db_ktrap(int type, db_regs_t *frame)
+{
+	int s;
+
+	ddb_regs = *frame;
+
+	s = splhigh();
+	db_active++;
+	cnpollc(1);
+	db_trap(type, 0);
+	cnpollc(0);
+	db_active--;
+	splx(s);
+
+	*frame = ddb_regs;
+}
diff --git a/sys/arch/powerpc64/powerpc64/db_trace.c b/sys/arch/powerpc64/powerpc64/db_trace.c
index f1236a40e9a..44c55dcf6d9 100644
--- a/sys/arch/powerpc64/powerpc64/db_trace.c
+++ b/sys/arch/powerpc64/powerpc64/db_trace.c
@@ -1,3 +1,32 @@
+/*	$OpenBSD: db_trace.c,v 1.2 2020/05/27 22:22:04 gkoehler Exp $	*/
+/*	$NetBSD: db_trace.c,v 1.15 1996/02/22 23:23:41 gwr Exp $	*/
+
+/*
+ * Mach Operating System
+ * Copyright (c) 1992 Carnegie Mellon University
+ * All Rights Reserved.
+ *
+ * Permission to use, copy, modify and distribute this software and its
+ * documentation is hereby granted, provided that both the copyright
+ * notice and this permission notice appear in all copies of the
+ * software, derivative works or modified versions, and any portions
+ * thereof, and that both notices appear in supporting documentation.
+ *
+ * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
+ * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
+ * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ *
+ * Carnegie Mellon requests users of this software to return to
+ *
+ *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
+ *  School of Computer Science
+ *  Carnegie Mellon University
+ *  Pittsburgh PA 15213-3890
+ *
+ * any improvements or extensions that they make and grant Carnegie Mellon
+ * the rights to redistribute these changes.
+ */
+
 #include <sys/param.h>
 
 #include <machine/db_machdep.h>
@@ -8,6 +37,44 @@
 db_regs_t ddb_regs;
 
 struct db_variable db_regs[] = {
+	{ "r0",  (long *)&ddb_regs.fixreg[0],	FCN_NULL },
+	{ "r1",  (long *)&ddb_regs.fixreg[1],	FCN_NULL },
+	{ "r2",  (long *)&ddb_regs.fixreg[2],	FCN_NULL },
+	{ "r3",  (long *)&ddb_regs.fixreg[3],	FCN_NULL },
+	{ "r4",  (long *)&ddb_regs.fixreg[4],	FCN_NULL },
+	{ "r5",  (long *)&ddb_regs.fixreg[5],	FCN_NULL },
+	{ "r6",  (long *)&ddb_regs.fixreg[6],	FCN_NULL },
+	{ "r7",  (long *)&ddb_regs.fixreg[7],	FCN_NULL },
+	{ "r8",  (long *)&ddb_regs.fixreg[8],	FCN_NULL },
+	{ "r9",  (long *)&ddb_regs.fixreg[9],	FCN_NULL },
+	{ "r10", (long *)&ddb_regs.fixreg[10],	FCN_NULL },
+	{ "r11", (long *)&ddb_regs.fixreg[11],	FCN_NULL },
+	{ "r12", (long *)&ddb_regs.fixreg[12],	FCN_NULL },
+	{ "r13", (long *)&ddb_regs.fixreg[13],	FCN_NULL },
+	{ "r14", (long *)&ddb_regs.fixreg[13],	FCN_NULL },
+	{ "r15", (long *)&ddb_regs.fixreg[13],	FCN_NULL },
+	{ "r16", (long *)&ddb_regs.fixreg[13],	FCN_NULL },
+	{ "r17", (long *)&ddb_regs.fixreg[17],	FCN_NULL },
+	{ "r18", (long *)&ddb_regs.fixreg[18],	FCN_NULL },
+	{ "r19", (long *)&ddb_regs.fixreg[19],	FCN_NULL },
+	{ "r20", (long *)&ddb_regs.fixreg[20],	FCN_NULL },
+	{ "r21", (long *)&ddb_regs.fixreg[21],	FCN_NULL },
+	{ "r22", (long *)&ddb_regs.fixreg[22],	FCN_NULL },
+	{ "r23", (long *)&ddb_regs.fixreg[23],	FCN_NULL },
+	{ "r24", (long *)&ddb_regs.fixreg[24],	FCN_NULL },
+	{ "r25", (long *)&ddb_regs.fixreg[25],	FCN_NULL },
+	{ "r26", (long *)&ddb_regs.fixreg[26],	FCN_NULL },
+	{ "r27", (long *)&ddb_regs.fixreg[27],	FCN_NULL },
+	{ "r28", (long *)&ddb_regs.fixreg[28],	FCN_NULL },
+	{ "r29", (long *)&ddb_regs.fixreg[29],	FCN_NULL },
+	{ "r30", (long *)&ddb_regs.fixreg[30],	FCN_NULL },
+	{ "r31", (long *)&ddb_regs.fixreg[31],	FCN_NULL },
+	{ "lr",  (long *)&ddb_regs.lr,		FCN_NULL },
+	{ "cr",  (long *)&ddb_regs.cr,		FCN_NULL },
+	{ "xer", (long *)&ddb_regs.xer,		FCN_NULL },
+	{ "ctr", (long *)&ddb_regs.ctr,		FCN_NULL },
+	{ "iar", (long *)&ddb_regs.srr0,		FCN_NULL },
+	{ "msr", (long *)&ddb_regs.srr1,		FCN_NULL },
 };
 
 struct db_variable *db_eregs = db_regs + nitems(db_regs);
diff --git a/sys/arch/powerpc64/powerpc64/locore.S b/sys/arch/powerpc64/powerpc64/locore.S
index de3b541ddc4..83760ed4d47 100644
--- a/sys/arch/powerpc64/powerpc64/locore.S
+++ b/sys/arch/powerpc64/powerpc64/locore.S
@@ -1,4 +1,4 @@
-/*	$OpenBSD: locore.S,v 1.3 2020/05/23 11:40:16 kettenis Exp $	*/
+/*	$OpenBSD: locore.S,v 1.4 2020/05/27 22:22:04 gkoehler Exp $	*/
 
 /*
  * Copyright (c) 2020 Mark Kettenis <kettenis@openbsd.org>
@@ -79,8 +79,10 @@ name:					\
 
 OPAL_CALL(OPAL_TEST, opal_test)
 OPAL_CALL(OPAL_CONSOLE_WRITE, opal_console_write)
+OPAL_CALL(OPAL_CONSOLE_READ, opal_console_read)
 OPAL_CALL(OPAL_CEC_POWER_DOWN, opal_cec_power_down)
 OPAL_CALL(OPAL_CEC_REBOOT, opal_cec_reboot)
+OPAL_CALL(OPAL_POLL_EVENTS, opal_poll_events)	
 	
 opal_call:
 	mflr	%r11
@@ -112,6 +114,7 @@ opal_call:
 #ifdef DDB
 	.globl db_enter
 db_enter:
+	trap
 	blr
 	
 	.globl setjmp
diff --git a/sys/arch/powerpc64/powerpc64/machdep.c b/sys/arch/powerpc64/powerpc64/machdep.c
index a0955df0ec2..d7677469bbc 100644
--- a/sys/arch/powerpc64/powerpc64/machdep.c
+++ b/sys/arch/powerpc64/powerpc64/machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: machdep.c,v 1.9 2020/05/23 11:40:16 kettenis Exp $	*/
+/*	$OpenBSD: machdep.c,v 1.10 2020/05/27 22:22:04 gkoehler Exp $	*/
 
 /*
  * Copyright (c) 2020 Mark Kettenis <kettenis@openbsd.org>
@@ -32,6 +32,12 @@
 #include <dev/ofw/fdt.h>
 #include <dev/cons.h>
 
+#ifdef DDB
+#include <machine/db_machdep.h>
+#include <ddb/db_extern.h>
+#include <ddb/db_interface.h>
+#endif
+
 int cacheline_size = 128;
 
 struct uvm_constraint_range  dma_constraint = { 0x0, (paddr_t)-1 };
@@ -62,6 +68,10 @@ extern char generictrap[];
 struct fdt_reg memreg[VM_PHYSSEG_MAX];
 int nmemreg;
 
+#ifdef DDB
+struct fdt_reg initrd_reg;
+#endif
+
 void memreg_add(const struct fdt_reg *);
 void memreg_remove(const struct fdt_reg *);
 
@@ -159,6 +169,13 @@ init_powernv(void *fdt, void *tocbase)
 	reg.size = round_page((paddr_t)fdt + fdt_get_size(fdt)) - reg.addr;
 	memreg_remove(&reg);
 
+#ifdef DDB
+	/* Load symbols from initrd. */
+	db_machine_init();
+	if (initrd_reg.addr != 0)
+		memreg_remove(&initrd_reg);
+#endif
+
 	uvm_setpagesize();
 
 	for (i = 0; i < nmemreg; i++) {
@@ -295,7 +312,16 @@ opal_cninit(struct consdev *cd)
 int
 opal_cngetc(dev_t dev)
 {
-	return -1;
+	uint64_t len;
+	char ch;
+
+	for (;;) {
+		len = 1;
+		opal_console_read(0, &len, &ch);
+		if (len)
+			return ch;
+		opal_poll_events(NULL);
+	}
 }
 
 void
diff --git a/sys/arch/powerpc64/powerpc64/trap.c b/sys/arch/powerpc64/powerpc64/trap.c
index 091acdfc15a..7f37d556d7c 100644
--- a/sys/arch/powerpc64/powerpc64/trap.c
+++ b/sys/arch/powerpc64/powerpc64/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.2 2020/05/22 15:34:43 kettenis Exp $	*/
+/*	$OpenBSD: trap.c,v 1.3 2020/05/27 22:22:04 gkoehler Exp $	*/
 
 /*
  * Copyright (c) 2020 Mark Kettenis <kettenis@openbsd.org>
@@ -19,10 +19,22 @@
 #include <sys/param.h>
 #include <sys/systm.h>
 
+#ifdef DDB
+#include <machine/db_machdep.h>
+#endif
 #include <machine/trap.h>
 
 void
 trap(struct trapframe *frame)
 {
+#ifdef DDB
+	/* At a trap instruction, enter the debugger. */
+	if (frame->exc == EXC_PGM && (frame->srr1 & EXC_PGM_TRAP)) {
+		db_ktrap(T_BREAKPOINT, frame);
+		frame->srr0 += 4; /* Step to next instruction. */
+		return;
+	}
+#endif
+
 	panic("trap type %lx at lr %lx", frame->exc, frame->lr);
 }
diff --git a/sys/arch/powerpc64/powerpc64/trap_subr.S b/sys/arch/powerpc64/powerpc64/trap_subr.S
index eeeaa41b759..332420481a9 100644
--- a/sys/arch/powerpc64/powerpc64/trap_subr.S
+++ b/sys/arch/powerpc64/powerpc64/trap_subr.S
@@ -1,4 +1,4 @@
-/* $OpenBSD: trap_subr.S,v 1.2 2020/05/22 16:27:49 kettenis Exp $ */
+/* $OpenBSD: trap_subr.S,v 1.3 2020/05/27 22:22:04 gkoehler Exp $ */
 /* $NetBSD: trap_subr.S,v 1.20 2002/04/22 23:20:08 kleink Exp $	*/
 
 /*-
@@ -128,7 +128,54 @@
 	std	%r30, FRAME_SRR0+48(%r1);				\
 	std	%r31, FRAME_SRR1+48(%r1);
 
-	
+#define FRAME_LEAVE(savearea)						\
+/* Now restore regs: */							\
+	ld	%r3, FRAME_LR+48(%r1);					\
+	ld	%r4, FRAME_CR+48(%r1);					\
+	ld	%r5, FRAME_XER+48(%r1);					\
+	ld	%r6, FRAME_CTR+48(%r1);					\
+	ld	%r7, FRAME_SRR0+48(%r1);				\
+	ld	%r8, FRAME_SRR1+48(%r1);				\
+	mtlr	%r3;							\
+	mtcr	%r4;							\
+	mtxer	%r5;							\
+	mtctr	%r6;							\
+	mtsrr0	%r7;							\
+	mtsrr1	%r8;							\
+	ld	%r0, FRAME_0+48(%r1);					\
+	ld	%r2, FRAME_2+48(%r1);					\
+	ld	%r3, FRAME_3+48(%r1);					\
+	ld	%r4, FRAME_4+48(%r1);					\
+	ld	%r5, FRAME_5+48(%r1);					\
+	ld	%r6, FRAME_6+48(%r1);					\
+	ld	%r7, FRAME_7+48(%r1);					\
+	ld	%r8, FRAME_8+48(%r1);					\
+	ld	%r9, FRAME_9+48(%r1);					\
+	ld	%r10, FRAME_10+48(%r1);					\
+	ld	%r11, FRAME_11+48(%r1);					\
+	ld	%r12, FRAME_12+48(%r1);					\
+	ld	%r13, FRAME_13+48(%r1);					\
+	ld	%r14, FRAME_14+48(%r1);					\
+	ld	%r15, FRAME_15+48(%r1);					\
+	ld	%r16, FRAME_16+48(%r1);					\
+	ld	%r17, FRAME_17+48(%r1);					\
+	ld	%r18, FRAME_18+48(%r1);					\
+	ld	%r19, FRAME_19+48(%r1);					\
+	ld	%r20, FRAME_20+48(%r1);					\
+	ld	%r21, FRAME_21+48(%r1);					\
+	ld	%r22, FRAME_22+48(%r1);					\
+	ld	%r23, FRAME_23+48(%r1);					\
+	ld	%r24, FRAME_24+48(%r1);					\
+	ld	%r25, FRAME_25+48(%r1);					\
+	ld	%r26, FRAME_26+48(%r1);					\
+	ld	%r27, FRAME_27+48(%r1);					\
+	ld	%r28, FRAME_28+48(%r1);					\
+	ld	%r29, FRAME_29+48(%r1);					\
+	ld	%r30, FRAME_30+48(%r1);					\
+	ld	%r31, FRAME_31+48(%r1);					\
+	ld	%r1, FRAME_1+48(%r1);
+
+
 	.text
 
 	.globl trapcode, trapcodeend
@@ -184,3 +231,6 @@ generictrap:
 	GET_TOCBASE(%r2)
 	addi	%r3, %r1, 48
 	bl	trap
+
+	FRAME_LEAVE(CI_TEMPSAVE)
+	rfid