[0/4] Further zImage work

[0/4] Further zImage work

[David Gibson]

The following patch series is an attempt to consolidate some of the
more settled ideas in the many zImage patches flying around at the
moment.

This patch series needs to be applied on top of patches 4-7 from
Milton Miller's recent series, and patch number 2 from Scott Wood's
most recent cuboot series (patch 1 from that series having already
been applied to powerpc.git).

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

[PATCH 1/4] powerpc: Add gcc format warnings to zImage printf()

[David Gibson]

This patch adds the correct attributes to the zImage's versions of
printf to make gcc generate format string mismatch warnings.  It also
corrects several minor problems with format strings in the zImage thus
discovered.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---

 arch/powerpc/boot/main.c  |    6 +++---
 arch/powerpc/boot/stdio.h |    4 ++--
 2 files changed, 5 insertions(+), 5 deletions(-)

Index: working-2.6/arch/powerpc/boot/stdio.h
===================================================================
--- working-2.6.orig/arch/powerpc/boot/stdio.h	2007-01-24 12:01:17.000000000 +1100
+++ working-2.6/arch/powerpc/boot/stdio.h	2007-03-20 14:04:41.000000000 +1100
@@ -7,11 +7,11 @@
 #define	EINVAL		22	/* Invalid argument */
 #define ENOSPC		28	/* No space left on device */
 
-extern int printf(const char *fmt, ...);
+extern int printf(const char *fmt, ...) __attribute__((format(printf, 1, 2)));
 
 #define fprintf(fmt, args...)	printf(args)
 
-extern int sprintf(char *buf, const char *fmt, ...);
+extern int sprintf(char *buf, const char *fmt, ...) __attribute__((format(printf, 2, 3)));
 
 extern int vsprintf(char *buf, const char *fmt, va_list args);
 
Index: working-2.6/arch/powerpc/boot/main.c
===================================================================
--- working-2.6.orig/arch/powerpc/boot/main.c	2007-03-20 14:03:26.000000000 +1100
+++ working-2.6/arch/powerpc/boot/main.c	2007-03-20 14:05:13.000000000 +1100
@@ -136,7 +136,7 @@ static struct addr_range prep_kernel(voi
 	} else {
 		if ((unsigned long)_start < ei.memsize)
 			fatal("Insufficient memory for kernel at address 0!"
-			       " (_start=%lx)\n\r", _start);
+			       " (_start=%p)\n\r", _start);
 	}
 
 	/* Finally, gunzip the kernel */
@@ -145,7 +145,7 @@ static struct addr_range prep_kernel(voi
 	/* discard up to the actual load data */
 	gunzip_discard(&gzstate, ei.elfoffset - sizeof(elfheader));
 	len = gunzip_finish(&gzstate, addr, ei.memsize);
-	printf("done 0x%lx bytes\n\r", len);
+	printf("done 0x%x bytes\n\r", len);
 
 	flush_cache(addr, ei.loadsize);
 
@@ -189,7 +189,7 @@ static struct addr_range prep_initrd(str
 		if (! initrd_addr)
 			fatal("Can't allocate memory for initial "
 			       "ramdisk !\n\r");
-		printf("Relocating initrd 0x%p <- 0x%p (0x%lx bytes)\n\r",
+		printf("Relocating initrd 0x%lx <- 0x%p (0x%lx bytes)\n\r",
 		       initrd_addr, old_addr, initrd_size);
 		memmove((void *)initrd_addr, old_addr, initrd_size);
 	}

[PATCH 2/4] powerpc: Add device tree utility functions to zImage

[David Gibson]

This patch adds a library of useful device tree manipulation functions
to the zImage library, for use by platform code.  These functions are
based on the hooks already in dt_ops, so they're not dependent on a
particular device tree implementation.  This patch also slightly
streamlines the code in main.c using these new functions.

This is a consolidation of my work in this area with Scott Wood's
patches to a very similar end.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---

 arch/powerpc/boot/Makefile  |    2 
 arch/powerpc/boot/devtree.c |  126 ++++++++++++++++++++++++++++++++++++++++++++
 arch/powerpc/boot/main.c    |   21 ++-----
 arch/powerpc/boot/ops.h     |   27 ++++++++-
 4 files changed, 160 insertions(+), 16 deletions(-)

Index: working-2.6/arch/powerpc/boot/ops.h
===================================================================
--- working-2.6.orig/arch/powerpc/boot/ops.h	2007-03-21 16:50:55.000000000 +1100
+++ working-2.6/arch/powerpc/boot/ops.h	2007-03-21 16:50:55.000000000 +1100
@@ -91,11 +91,16 @@ static inline int getprop(void *devp, co
 	return (dt_ops.getprop) ? dt_ops.getprop(devp, name, buf, buflen) : -1;
 }
 
-static inline int setprop(void *devp, const char *name, void *buf, int buflen)
+static inline int setprop(void *devp, const char *name,
+			  const void *buf, int buflen)
 {
 	return (dt_ops.setprop) ? dt_ops.setprop(devp, name, buf, buflen) : -1;
 }
-
+#define setprop_val(devp, name, val) \
+	do { \
+		typeof(val) x = (val); \
+		setprop((devp), (name), &x, sizeof(x)); \
+	} while(0)
 static inline int setprop_str(void *devp, const char *name, const char *buf)
 {
 	if (dt_ops.setprop)
@@ -140,6 +145,24 @@ static inline void *find_node_by_devtype
 	return find_node_by_prop_value_str(prev, "device_type", type);
 }
 
+int dt_path_getprop(const char *path, const char *name, void *buf, int bufsize);
+void dt_path_setprop(const char *path, const char *name, void *val, int size);
+#define dt_path_setprop_val(path, name, val)	\
+	do { \
+		typeof(val) x = (val); \
+		dt_path_setprop((path),(name),&x,sizeof(x)); \
+	} while (0)
+#define dt_path_setprop_str(path, name, str) \
+	dt_path_setprop((path), (name), (str), strlen(str)+1)
+
+void dt_fixup_memory(u64 start, u64 size);
+void dt_fixup_cpu_clocks(u32 cpufreq, u32 tbfreq, u32 busfreq);
+void dt_fixup_clock(const char *path, u32 freq);
+void __dt_fixup_mac_addresses(u32 startindex, ...);
+#define dt_fixup_mac_addresses(...) \
+	__dt_fixup_mac_addresses(0, __VA_ARGS__, NULL)
+
+
 static inline void *malloc(u32 size)
 {
 	return (platform_ops.malloc) ? platform_ops.malloc(size) : NULL;
Index: working-2.6/arch/powerpc/boot/Makefile
===================================================================
--- working-2.6.orig/arch/powerpc/boot/Makefile	2007-03-21 16:50:55.000000000 +1100
+++ working-2.6/arch/powerpc/boot/Makefile	2007-03-21 16:50:55.000000000 +1100
@@ -42,7 +42,7 @@ $(addprefix $(obj)/,$(zlib) main.o): $(a
 
 src-wlib := string.S crt0.S stdio.c main.c flatdevtree.c flatdevtree_misc.c \
 		ns16550.c serial.c simple_alloc.c div64.S util.S \
-		gunzip_util.c $(zlib)
+		gunzip_util.c $(zlib) devtree.c
 src-plat := of.c
 src-boot := $(src-wlib) $(src-plat) empty.c
 
Index: working-2.6/arch/powerpc/boot/main.c
===================================================================
--- working-2.6.orig/arch/powerpc/boot/main.c	2007-03-21 16:50:55.000000000 +1100
+++ working-2.6/arch/powerpc/boot/main.c	2007-03-21 16:50:55.000000000 +1100
@@ -156,9 +156,6 @@ static struct addr_range prep_initrd(str
 				     unsigned long initrd_addr,
 				     unsigned long initrd_size)
 {
-	void *devp;
-	u32 initrd_start, initrd_end;
-
 	/* If we have an image attached to us, it overrides anything
 	 * supplied by the loader. */
 	if (_initrd_end > _initrd_start) {
@@ -197,16 +194,10 @@ static struct addr_range prep_initrd(str
 	printf("initrd head: 0x%lx\n\r", *((unsigned long *)initrd_addr));
 
 	/* Tell the kernel initrd address via device tree */
-	devp = finddevice("/chosen");
-	if (! devp)
-		fatal("Device tree has no chosen node!\n\r");
-
-	initrd_start = (u32)initrd_addr;
-	initrd_end = (u32)initrd_addr + initrd_size;
-
-	setprop(devp, "linux,initrd-start", &initrd_start,
-		sizeof(initrd_start));
-	setprop(devp, "linux,initrd-end", &initrd_end, sizeof(initrd_end));
+	dt_path_setprop_val("/chosen", "linux,initrd-start",
+			    (u32)(initrd_addr));
+	dt_path_setprop_val("/chosen", "linux,initrd-end",
+			    (u32)(initrd_addr + initrd_size));
 
 	return (struct addr_range){(void *)initrd_addr, initrd_size};
 }
@@ -262,6 +253,10 @@ void start(void *sp)
 	printf("\n\rzImage starting: loaded at 0x%p (sp: 0x%p)\n\r",
 	       _start, sp);
 
+	/* Ensure that the device tree has a /chosen node */
+	if (! finddevice("/chosen"))
+		create_node(NULL, "chosen");
+
 	vmlinux = prep_kernel();
 	initrd = prep_initrd(vmlinux, loader_info.initrd_addr,
 			     loader_info.initrd_size);
Index: working-2.6/arch/powerpc/boot/devtree.c
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ working-2.6/arch/powerpc/boot/devtree.c	2007-03-21 16:50:55.000000000 +1100
@@ -0,0 +1,126 @@
+/*
+ * devtree.c - convenience functions for device tree manipulation
+ * Copyright 2007 David Gibson, IBM Corporation.
+ * Copyright (c) 2007 Freescale Semiconductor, Inc.
+ *
+ * Authors: David Gibson <david@gibson.dropbear.id.au>
+ *	    Scott Wood <scottwood@freescale.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+#include <stdarg.h>
+#include <stddef.h>
+#include "types.h"
+#include "string.h"
+#include "stdio.h"
+#include "ops.h"
+
+int dt_path_getprop(const char *path, const char *name, void *buf, int bufsize)
+{
+	void *devp = finddevice;
+
+	if (devp)
+		return getprop(devp, name, buf, bufsize);
+	return -1;
+}
+
+void dt_path_setprop(const char *path, const char *name, void *val, int size)
+{
+	void *devp = finddevice(path);
+
+	if (! devp)
+		fatal("Couldn't find node %s to poke\n\r", path);
+
+	if (setprop(devp, name, val, size) != 0)
+		fatal("Couldn't set %s property in %s\n\r", name, path);
+}
+
+void dt_fixup_memory(u64 start, u64 size)
+{
+	void *devp;
+	int naddr, nsize, i;
+	u32 memreg[4];
+
+	if (dt_path_getprop("/", "#address-cells", &naddr, sizeof(naddr)) != 0)
+		naddr = 2;
+	if (naddr < 1 || naddr > 2)
+		fatal("Can't cope with #address-cells == %d in /\n\r", naddr);
+
+	if (dt_path_getprop("/", "#size-cells", &nsize, sizeof(nsize)) != 0)
+		nsize = 1;
+	if (nsize < 1 || nsize > 2)
+		fatal("Can't cope with #size-cells == %d in /\n\r", nsize);
+
+	i = 0;
+	if (naddr == 2)
+		memreg[i++] = start >> 32;
+	memreg[i++] = start & 0xffffffff;
+	if (nsize == 2)
+		memreg[i++] = size >> 32;
+	memreg[i++] = size & 0xffffffff;
+
+	devp = finddevice("/memory");
+	if (! devp) {
+		void *devp = create_node(NULL, "memory");
+		setprop_str(devp, "device_type", "memory");
+	}
+
+	printf("Memory <- <0x%x", memreg[0]);
+	for (i = 1; i < (naddr + nsize); i++)
+		printf(" 0x%x", memreg[i]);
+	printf("> (%ldMB)\n\r", (unsigned long)(size >> 20));
+
+	setprop(devp, "reg", memreg, (naddr + nsize)*sizeof(u32));
+}
+
+#define MHZ(x)	((x + 500000) / 1000000)
+
+void dt_fixup_cpu_clocks(u32 cpu, u32 tb, u32 bus)
+{
+	void *devp = NULL;
+
+	printf("CPU clock-frequency <- 0x%x (%dMHz)\n\r", cpu, MHZ(cpu));
+	printf("CPU timebase-frequency <- 0x%x (%dMHz)\n\r", tb, MHZ(tb));
+	if (bus > 0)
+		printf("CPU bus-frequency <- 0x%x (%dMHz)\n\r", bus, MHZ(bus));
+
+	while ((devp = find_node_by_devtype(devp, "cpu"))) {
+		setprop_val(devp, "clock-frequency", cpu);
+		setprop_val(devp, "timebase-frequency", tb);
+		if (bus > 0)
+			setprop_val(devp, "bus-frequency", bus);
+	}
+}
+
+void dt_fixup_clock(const char *path, u32 freq)
+{
+	printf("%s: clock-frequency <- %x (%dMHz)\n\r", path, freq, MHZ(freq));
+	dt_path_setprop_val(path, "clock-frequency", freq);
+}
+
+void __dt_fixup_mac_addresses(u32 startindex, ...)
+{
+	va_list ap;
+	u32 index = startindex;
+	void *devp;
+	const u8 *addr;
+
+	va_start(ap, startindex);
+	while ((addr = va_arg(ap, const u8 *))) {
+		devp = find_node_by_prop_value(NULL, "linux,network-index",
+					       (void*)&index, sizeof(index));
+
+		printf("ENET%d: local-mac-address <-"
+		       " %02x:%02x:%02x:%02x:%02x:%02x\n\r", index,
+		       addr[0], addr[1], addr[2], addr[3], addr[4], addr[5]);
+
+		if (devp)
+			setprop(devp, "local-mac-address", addr, 6);
+
+		index++;
+	}
+	va_end(ap);
+}

[PATCH 3/4] powerpc: Clean up zImage handling of the command line

[David Gibson]

This patch cleans up how the zImage code manipulates the kernel
command line.  Notable improvements from the old handling:
	- Command line manipulation is consolidated into a new
prep_cmdline() function, rather than being scattered across start()
and some helper functions
	- Less stack space use: we use just a single global command
line buffer, which can be initialized by an external tool as before,
we no longer need another command line sized buffer on the stack.
	- Easier to support platforms whose firmware passes a
commandline, but not a device tree.  Platform code can now point new
loader_info fields to the firmware's command line, rather than having
to do early manipulation of the /chosen bootargs property which may
then be rewritten again by the core.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---

 arch/powerpc/boot/main.c |   55 +++++++++++++++++------------------------------
 arch/powerpc/boot/ops.h  |    2 +
 2 files changed, 23 insertions(+), 34 deletions(-)

Index: working-2.6/arch/powerpc/boot/main.c
===================================================================
--- working-2.6.orig/arch/powerpc/boot/main.c	2007-03-21 16:50:55.000000000 +1100
+++ working-2.6/arch/powerpc/boot/main.c	2007-03-21 16:59:37.000000000 +1100
@@ -206,31 +206,23 @@ static struct addr_range prep_initrd(str
  * edit the command line passed to vmlinux (by setting /chosen/bootargs).
  * The buffer is put in it's own section so that tools may locate it easier.
  */
-static char builtin_cmdline[COMMAND_LINE_SIZE]
+static char cmdline[COMMAND_LINE_SIZE]
 	__attribute__((__section__("__builtin_cmdline")));
 
-static void get_cmdline(char *buf, int size)
+static void prep_cmdline(void)
 {
-	void *devp;
-	int len = strlen(builtin_cmdline);
+	if (cmdline[0] == '\0')
+		dt_path_getprop("/chosen", "bootargs",
+				cmdline, COMMAND_LINE_SIZE-1);
+
+	printf("\n\rLinux/PowerPC load: %s", cmdline);
+	/* If possible, edit the command line */
+	if (console_ops.edit_cmdline)
+		console_ops.edit_cmdline(cmdline, COMMAND_LINE_SIZE);
+	printf("\n\r");
 
-	buf[0] = '\0';
-
-	if (len > 0) { /* builtin_cmdline overrides dt's /chosen/bootargs */
-		len = min(len, size-1);
-		strncpy(buf, builtin_cmdline, len);
-		buf[len] = '\0';
-	}
-	else if ((devp = finddevice("/chosen")))
-		getprop(devp, "bootargs", buf, size);
-}
-
-static void set_cmdline(char *buf)
-{
-	void *devp;
-
-	if ((devp = finddevice("/chosen")))
-		setprop(devp, "bootargs", buf, strlen(buf) + 1);
+	/* Put the command line back into the devtree for the kernel */
+	dt_path_setprop_str("/chosen", "bootargs", cmdline);
 }
 
 struct platform_ops platform_ops;
@@ -242,9 +234,15 @@ void start(void *sp)
 {
 	struct addr_range vmlinux, initrd;
 	kernel_entry_t kentry;
-	char cmdline[COMMAND_LINE_SIZE];
 	unsigned long ft_addr = 0;
 
+	/* Do this first, because malloc() could clobber the loader's
+	 * command line.  Only use the loader command line if a
+	 * built-in command line wasn't set by an external tool */
+	if ((loader_info.cmdline_len > 0) && (cmdline[0] == '\0'))
+		memmove(cmdline, loader_info.cmdline,
+			min(loader_info.cmdline_len, COMMAND_LINE_SIZE-1));
+
 	if (console_ops.open && (console_ops.open() < 0))
 		exit();
 	if (platform_ops.fixups)
@@ -260,18 +258,7 @@ void start(void *sp)
 	vmlinux = prep_kernel();
 	initrd = prep_initrd(vmlinux, loader_info.initrd_addr,
 			     loader_info.initrd_size);
-
-	/* If cmdline came from zimage wrapper or if we can edit the one
-	 * in the dt, print it out and edit it, if possible.
-	 */
-	if ((strlen(builtin_cmdline) > 0) || console_ops.edit_cmdline) {
-		get_cmdline(cmdline, COMMAND_LINE_SIZE);
-		printf("\n\rLinux/PowerPC load: %s", cmdline);
-		if (console_ops.edit_cmdline)
-			console_ops.edit_cmdline(cmdline, COMMAND_LINE_SIZE);
-		printf("\n\r");
-		set_cmdline(cmdline);
-	}
+	prep_cmdline();
 
 	printf("Finalizing device tree...");
 	if (dt_ops.finalize)
Index: working-2.6/arch/powerpc/boot/ops.h
===================================================================
--- working-2.6.orig/arch/powerpc/boot/ops.h	2007-03-21 16:50:55.000000000 +1100
+++ working-2.6/arch/powerpc/boot/ops.h	2007-03-21 16:59:37.000000000 +1100
@@ -70,6 +70,8 @@ struct serial_console_data {
 struct loader_info {
 	void *promptr;
 	unsigned long initrd_addr, initrd_size;
+	char *cmdline;
+	int cmdline_len;
 };
 extern struct loader_info loader_info;
 

[PATCH 4/4] powerpc: New reg.h for the zImage

[David Gibson]

This patch adds a reg.h to the zImage code, with common definitions
for accessing system reigsters.  For now, this includes functions for
retreiving the PVR and the stack pointer.  This patch then uses the
new reg.h to let start() display the running stack address without
having to explicitly pass the stack as a parameter from the asm code.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---

 arch/powerpc/boot/crt0.S |    1 -
 arch/powerpc/boot/main.c |    5 +++--
 arch/powerpc/boot/ops.h  |    2 +-
 arch/powerpc/boot/reg.h  |   22 ++++++++++++++++++++++
 4 files changed, 26 insertions(+), 4 deletions(-)

Index: working-2.6/arch/powerpc/boot/reg.h
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ working-2.6/arch/powerpc/boot/reg.h	2007-03-21 17:28:38.000000000 +1100
@@ -0,0 +1,22 @@
+#ifndef _PPC_BOOT_REG_H
+#define _PPC_BOOT_REG_H
+/*
+ * Copyright 2007 Davud Gibson, IBM Corporation.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+static inline u32 mfpvr(void)
+{
+	u32 pvr;
+	asm volatile ("mfpvr	%0" : "=r"(pvr));
+	return pvr;
+}
+
+register void *__stack_pointer asm("r1");
+#define get_sp()	(__stack_pointer)
+
+#endif	/* _PPC_BOOT_REG_H */
Index: working-2.6/arch/powerpc/boot/crt0.S
===================================================================
--- working-2.6.orig/arch/powerpc/boot/crt0.S	2007-03-21 17:24:48.000000000 +1100
+++ working-2.6/arch/powerpc/boot/crt0.S	2007-03-21 17:24:48.000000000 +1100
@@ -97,5 +97,4 @@ _zimage_start_lib:
 	bl	platform_init
 
 	/* Call start */
-	mr	r3,r1
 	b	start
Index: working-2.6/arch/powerpc/boot/main.c
===================================================================
--- working-2.6.orig/arch/powerpc/boot/main.c	2007-03-21 17:24:48.000000000 +1100
+++ working-2.6/arch/powerpc/boot/main.c	2007-03-21 17:24:48.000000000 +1100
@@ -17,6 +17,7 @@
 #include "ops.h"
 #include "gunzip_util.h"
 #include "flatdevtree.h"
+#include "reg.h"
 
 extern char _start[];
 extern char __bss_start[];
@@ -230,7 +231,7 @@ struct dt_ops dt_ops;
 struct console_ops console_ops;
 struct loader_info loader_info;
 
-void start(void *sp)
+void start(void)
 {
 	struct addr_range vmlinux, initrd;
 	kernel_entry_t kentry;
@@ -249,7 +250,7 @@ void start(void *sp)
 		platform_ops.fixups();
 
 	printf("\n\rzImage starting: loaded at 0x%p (sp: 0x%p)\n\r",
-	       _start, sp);
+	       _start, get_sp());
 
 	/* Ensure that the device tree has a /chosen node */
 	if (! finddevice("/chosen"))
Index: working-2.6/arch/powerpc/boot/ops.h
===================================================================
--- working-2.6.orig/arch/powerpc/boot/ops.h	2007-03-21 17:24:48.000000000 +1100
+++ working-2.6/arch/powerpc/boot/ops.h	2007-03-21 17:24:48.000000000 +1100
@@ -75,7 +75,7 @@ struct loader_info {
 };
 extern struct loader_info loader_info;
 
-void start(void *sp);
+void start(void);
 int ft_init(void *dt_blob, unsigned int max_size, unsigned int max_find_device);
 int serial_console_init(void);
 int ns16550_console_init(void *devp, struct serial_console_data *scdp);

Re: [PATCH 2/4] powerpc: Add device tree utility functions to zImage

[Milton Miller]

Following your reply to Scott's comments about space in the xlate_reg
thread, how about splitting the ones used in main.c which will always
be included from the others that are more for device tree pokers.

For that matter, your streamlining adds runtime overhead.  Why not
cache the checked or created phandle?

Also, in dt_path_getprop, did you want to call finddevice instead of
testing the function is not weak and undefined?

milton

Re: [PATCH 1/4] powerpc: Add gcc format warnings to zImage printf()

[Milton Miller]

+extern int sprintf(char *buf, const char *fmt, ...) __attribute__((format(printf, 2, 3)));

you exceeded 80 columns by 10.

milton

Re: [PATCH 2/4] powerpc: Add device tree utility functions to zImage

[Segher Boessenkool]

> @@ -262,6 +253,10 @@ void start(void *sp)
>  	printf("\n\rzImage starting: loaded at 0x%p (sp: 0x%p)\n\r",
>  	       _start, sp);
>
> +	/* Ensure that the device tree has a /chosen node */
> +	if (! finddevice("/chosen"))
> +		create_node(NULL, "chosen");
> +
>  	vmlinux = prep_kernel();
>  	initrd = prep_initrd(vmlinux, loader_info.initrd_addr,
>  			     loader_info.initrd_size);

So this is done early, and unconditional now?  Just
double checking, not enough context (for me, anyway)
in the patch itself.


Segher

Re: [PATCH 2/4] powerpc: Add device tree utility functions to zImage

[Scott Wood]

On Wed, Mar 21, 2007 at 05:31:49PM +1100, David Gibson wrote:
> +int dt_path_getprop(const char *path, const char *name, void *buf, int bufsize)
> +{
> +	void *devp = finddevice;
> +
> +	if (devp)
> +		return getprop(devp, name, buf, bufsize);
> +	return -1;
> +}

Should be "void *devp = finddevice(path);".

-Scott

Re: [PATCH 2/4] powerpc: Add device tree utility functions to zImage

[David Gibson]

On Wed, Mar 21, 2007 at 06:10:21PM +0100, Segher Boessenkool wrote:
> > @@ -262,6 +253,10 @@ void start(void *sp)
> >  	printf("\n\rzImage starting: loaded at 0x%p (sp: 0x%p)\n\r",
> >  	       _start, sp);
> >
> > +	/* Ensure that the device tree has a /chosen node */
> > +	if (! finddevice("/chosen"))
> > +		create_node(NULL, "chosen");
> > +
> >  	vmlinux = prep_kernel();
> >  	initrd = prep_initrd(vmlinux, loader_info.initrd_addr,
> >  			     loader_info.initrd_size);
> 
> So this is done early, and unconditional now?  Just
> double checking, not enough context (for me, anyway)
> in the patch itself.

Yes, that's right.

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

Re: [PATCH 1/4] powerpc: Add gcc format warnings to zImage printf()

[David Gibson]

On Wed, Mar 21, 2007 at 09:03:19AM -0600, Milton Miller wrote:
> 
> +extern int sprintf(char *buf, const char *fmt, ...) __attribute__((format(printf, 2, 3)));
> 
> you exceeded 80 columns by 10.

Revised in second spin.

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

Re: [PATCH 2/4] powerpc: Add device tree utility functions to zImage

[David Gibson]

On Wed, Mar 21, 2007 at 04:57:41PM -0500, Scott Wood wrote:
> On Wed, Mar 21, 2007 at 05:31:49PM +1100, David Gibson wrote:
> > +int dt_path_getprop(const char *path, const char *name, void *buf, int bufsize)
> > +{
> > +	void *devp = finddevice;
> > +
> > +	if (devp)
> > +		return getprop(devp, name, buf, bufsize);
> > +	return -1;
> > +}
> 
> Should be "void *devp = finddevice(path);".

Eep.  Yes.

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

Re: [PATCH 2/4] powerpc: Add device tree utility functions to zImage

[David Gibson]

On Wed, Mar 21, 2007 at 09:03:02AM -0600, Milton Miller wrote:
> 
> Following your reply to Scott's comments about space in the xlate_reg
> thread, how about splitting the ones used in main.c which will always
> be included from the others that are more for device tree pokers.

Yeah, I guess.

> For that matter, your streamlining adds runtime overhead.  Why not
> cache the checked or created phandle?

Well, I made a judgeement that source simplicity was more valuable
than runtime speed.  However, in the second spin, I've reconsidered
and gotten rid of the dt_path_{get,set}prop functions entirely which
addresses both concerns above.

> Also, in dt_path_getprop, did you want to call finddevice instead of
> testing the function is not weak and undefined?

Yes.  Fixed now.

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

[0/4] Further zImage work (spin 2)

[David Gibson]

Ok, here's a revised version of that last series of zImage work.  This
now applies on top of the for-2.6.22 branch of powerpc.git, plus
Milton's latest zImage patch series.

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

[PATCH 1/4] powerpc: Add gcc format warnings to zImage printf()

[David Gibson]

This patch adds the correct attributes to the zImage's versions of
printf to make gcc generate format string mismatch warnings.  It also
corrects several minor problems with format strings in the zImage thus
discovered.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---

 arch/powerpc/boot/main.c  |    6 +++---
 arch/powerpc/boot/stdio.h |    5 +++--
 2 files changed, 6 insertions(+), 5 deletions(-)

Index: working-2.6/arch/powerpc/boot/stdio.h
===================================================================
--- working-2.6.orig/arch/powerpc/boot/stdio.h	2007-01-24 12:01:17.000000000 +1100
+++ working-2.6/arch/powerpc/boot/stdio.h	2007-03-22 12:35:08.000000000 +1100
@@ -7,11 +7,12 @@
 #define	EINVAL		22	/* Invalid argument */
 #define ENOSPC		28	/* No space left on device */
 
-extern int printf(const char *fmt, ...);
+extern int printf(const char *fmt, ...) __attribute__((format(printf, 1, 2)));
 
 #define fprintf(fmt, args...)	printf(args)
 
-extern int sprintf(char *buf, const char *fmt, ...);
+extern int sprintf(char *buf, const char *fmt, ...)
+	__attribute__((format(printf, 2, 3)));
 
 extern int vsprintf(char *buf, const char *fmt, va_list args);
 
Index: working-2.6/arch/powerpc/boot/main.c
===================================================================
--- working-2.6.orig/arch/powerpc/boot/main.c	2007-03-22 12:26:06.000000000 +1100
+++ working-2.6/arch/powerpc/boot/main.c	2007-03-22 12:33:49.000000000 +1100
@@ -136,7 +136,7 @@ static struct addr_range prep_kernel(voi
 	} else {
 		if ((unsigned long)_start < ei.memsize)
 			fatal("Insufficient memory for kernel at address 0!"
-			       " (_start=%lx)\n\r", _start);
+			       " (_start=%p)\n\r", _start);
 	}
 
 	/* Finally, gunzip the kernel */
@@ -145,7 +145,7 @@ static struct addr_range prep_kernel(voi
 	/* discard up to the actual load data */
 	gunzip_discard(&gzstate, ei.elfoffset - sizeof(elfheader));
 	len = gunzip_finish(&gzstate, addr, ei.memsize);
-	printf("done 0x%lx bytes\n\r", len);
+	printf("done 0x%x bytes\n\r", len);
 
 	flush_cache(addr, ei.loadsize);
 
@@ -189,7 +189,7 @@ static struct addr_range prep_initrd(str
 		if (! initrd_addr)
 			fatal("Can't allocate memory for initial "
 			       "ramdisk !\n\r");
-		printf("Relocating initrd 0x%p <- 0x%p (0x%lx bytes)\n\r",
+		printf("Relocating initrd 0x%lx <- 0x%p (0x%lx bytes)\n\r",
 		       initrd_addr, old_addr, initrd_size);
 		memmove((void *)initrd_addr, old_addr, initrd_size);
 	}

[PATCH 2/4] powerpc: Add device tree utility functions to zImage

[David Gibson]

This patch adds a library of useful device tree manipulation functions
to the zImage library, for use by platform code.  These functions are
based on the hooks already in dt_ops, so they're not dependent on a
particular device tree implementation.  This patch also slightly
streamlines the code in main.c using these new functions.

This is a consolidation of my work in this area with Scott Wood's
patches to a very similar end.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---

 arch/powerpc/boot/Makefile  |    2 
 arch/powerpc/boot/devtree.c |  111 ++++++++++++++++++++++++++++++++++++++++++++
 arch/powerpc/boot/main.c    |   27 ++++------
 arch/powerpc/boot/ops.h     |   13 +++++
 4 files changed, 136 insertions(+), 17 deletions(-)

Index: working-2.6/arch/powerpc/boot/ops.h
===================================================================
--- working-2.6.orig/arch/powerpc/boot/ops.h	2007-03-22 13:47:16.000000000 +1100
+++ working-2.6/arch/powerpc/boot/ops.h	2007-03-22 13:57:23.000000000 +1100
@@ -96,6 +96,11 @@ static inline int setprop(void *devp, co
 {
 	return (dt_ops.setprop) ? dt_ops.setprop(devp, name, buf, buflen) : -1;
 }
+#define setprop_val(devp, name, val) \
+	do { \
+		typeof(val) x = (val); \
+		setprop((devp), (name), &x, sizeof(x)); \
+	} while (0)
 
 static inline int setprop_str(void *devp, const char *name, const char *buf)
 {
@@ -141,6 +146,14 @@ static inline void *find_node_by_devtype
 	return find_node_by_prop_value_str(prev, "device_type", type);
 }
 
+void dt_fixup_memory(u64 start, u64 size);
+void dt_fixup_cpu_clocks(u32 cpufreq, u32 tbfreq, u32 busfreq);
+void dt_fixup_clock(const char *path, u32 freq);
+void __dt_fixup_mac_addresses(u32 startindex, ...);
+#define dt_fixup_mac_addresses(...) \
+	__dt_fixup_mac_addresses(0, __VA_ARGS__, NULL)
+
+
 static inline void *malloc(u32 size)
 {
 	return (platform_ops.malloc) ? platform_ops.malloc(size) : NULL;
Index: working-2.6/arch/powerpc/boot/Makefile
===================================================================
--- working-2.6.orig/arch/powerpc/boot/Makefile	2007-03-22 13:47:17.000000000 +1100
+++ working-2.6/arch/powerpc/boot/Makefile	2007-03-22 13:57:21.000000000 +1100
@@ -42,7 +42,7 @@ $(addprefix $(obj)/,$(zlib) main.o): $(a
 
 src-wlib := string.S crt0.S stdio.c main.c flatdevtree.c flatdevtree_misc.c \
 		ns16550.c serial.c simple_alloc.c div64.S util.S \
-		gunzip_util.c $(zlib)
+		gunzip_util.c $(zlib) devtree.c
 src-plat := of.c
 src-boot := $(src-wlib) $(src-plat) empty.c
 
Index: working-2.6/arch/powerpc/boot/main.c
===================================================================
--- working-2.6.orig/arch/powerpc/boot/main.c	2007-03-22 13:47:17.000000000 +1100
+++ working-2.6/arch/powerpc/boot/main.c	2007-03-22 13:57:23.000000000 +1100
@@ -152,13 +152,10 @@ static struct addr_range prep_kernel(voi
 	return (struct addr_range){addr, ei.memsize};
 }
 
-static struct addr_range prep_initrd(struct addr_range vmlinux,
+static struct addr_range prep_initrd(struct addr_range vmlinux, void *chosen,
 				     unsigned long initrd_addr,
 				     unsigned long initrd_size)
 {
-	void *devp;
-	u32 initrd_start, initrd_end;
-
 	/* If we have an image attached to us, it overrides anything
 	 * supplied by the loader. */
 	if (_initrd_end > _initrd_start) {
@@ -197,16 +194,8 @@ static struct addr_range prep_initrd(str
 	printf("initrd head: 0x%lx\n\r", *((unsigned long *)initrd_addr));
 
 	/* Tell the kernel initrd address via device tree */
-	devp = finddevice("/chosen");
-	if (! devp)
-		fatal("Device tree has no chosen node!\n\r");
-
-	initrd_start = (u32)initrd_addr;
-	initrd_end = (u32)initrd_addr + initrd_size;
-
-	setprop(devp, "linux,initrd-start", &initrd_start,
-		sizeof(initrd_start));
-	setprop(devp, "linux,initrd-end", &initrd_end, sizeof(initrd_end));
+	setprop_val(chosen, "linux,initrd-start", (u32)(initrd_addr));
+	setprop_val(chosen, "linux,initrd-end", (u32)(initrd_addr+initrd_size));
 
 	return (struct addr_range){(void *)initrd_addr, initrd_size};
 }
@@ -253,6 +242,7 @@ void start(void *sp)
 	kernel_entry_t kentry;
 	char cmdline[COMMAND_LINE_SIZE];
 	unsigned long ft_addr = 0;
+	void *chosen;
 
 	if (console_ops.open && (console_ops.open() < 0))
 		exit();
@@ -262,9 +252,14 @@ void start(void *sp)
 	printf("\n\rzImage starting: loaded at 0x%p (sp: 0x%p)\n\r",
 	       _start, sp);
 
+	/* Ensure that the device tree has a /chosen node */
+	chosen = finddevice("/chosen");
+	if (! chosen)
+		chosen = create_node(NULL, "chosen");
+
 	vmlinux = prep_kernel();
-	initrd = prep_initrd(vmlinux, loader_info.initrd_addr,
-			     loader_info.initrd_size);
+	initrd = prep_initrd(vmlinux, chosen,
+			     loader_info.initrd_addr, loader_info.initrd_size);
 
 	/* If cmdline came from zimage wrapper or if we can edit the one
 	 * in the dt, print it out and edit it, if possible.
Index: working-2.6/arch/powerpc/boot/devtree.c
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ working-2.6/arch/powerpc/boot/devtree.c	2007-03-22 13:58:15.000000000 +1100
@@ -0,0 +1,111 @@
+/*
+ * devtree.c - convenience functions for device tree manipulation
+ * Copyright 2007 David Gibson, IBM Corporation.
+ * Copyright (c) 2007 Freescale Semiconductor, Inc.
+ *
+ * Authors: David Gibson <david@gibson.dropbear.id.au>
+ *	    Scott Wood <scottwood@freescale.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+#include <stdarg.h>
+#include <stddef.h>
+#include "types.h"
+#include "string.h"
+#include "stdio.h"
+#include "ops.h"
+
+void dt_fixup_memory(u64 start, u64 size)
+{
+	void *root, *memory;
+	int naddr, nsize, i;
+	u32 memreg[4];
+
+	root = finddevice("/");
+	if (getprop(root, "#address-cells", &naddr, sizeof(naddr)) < 0)
+		naddr = 2;
+	if (naddr < 1 || naddr > 2)
+		fatal("Can't cope with #address-cells == %d in /\n\r", naddr);
+
+	if (getprop(root, "#size-cells", &nsize, sizeof(nsize)) < 0)
+		nsize = 1;
+	if (nsize < 1 || nsize > 2)
+		fatal("Can't cope with #size-cells == %d in /\n\r", nsize);
+
+	i = 0;
+	if (naddr == 2)
+		memreg[i++] = start >> 32;
+	memreg[i++] = start & 0xffffffff;
+	if (nsize == 2)
+		memreg[i++] = size >> 32;
+	memreg[i++] = size & 0xffffffff;
+
+	memory = finddevice("/memory");
+	if (! memory) {
+		memory = create_node(NULL, "memory");
+		setprop_str(memory, "device_type", "memory");
+	}
+
+	printf("Memory <- <0x%x", memreg[0]);
+	for (i = 1; i < (naddr + nsize); i++)
+		printf(" 0x%x", memreg[i]);
+	printf("> (%ldMB)\n\r", (unsigned long)(size >> 20));
+
+	setprop(memory, "reg", memreg, (naddr + nsize)*sizeof(u32));
+}
+
+#define MHZ(x)	((x + 500000) / 1000000)
+
+void dt_fixup_cpu_clocks(u32 cpu, u32 tb, u32 bus)
+{
+	void *devp = NULL;
+
+	printf("CPU clock-frequency <- 0x%x (%dMHz)\n\r", cpu, MHZ(cpu));
+	printf("CPU timebase-frequency <- 0x%x (%dMHz)\n\r", tb, MHZ(tb));
+	if (bus > 0)
+		printf("CPU bus-frequency <- 0x%x (%dMHz)\n\r", bus, MHZ(bus));
+
+	while ((devp = find_node_by_devtype(devp, "cpu"))) {
+		setprop_val(devp, "clock-frequency", cpu);
+		setprop_val(devp, "timebase-frequency", tb);
+		if (bus > 0)
+			setprop_val(devp, "bus-frequency", bus);
+	}
+}
+
+void dt_fixup_clock(const char *path, u32 freq)
+{
+	void *devp = finddevice(path);
+
+	if (devp) {
+		printf("%s: clock-frequency <- %x (%dMHz)\n\r", path, freq, MHZ(freq));
+		setprop_val(devp, "clock-frequency", freq);
+	}
+}
+
+void __dt_fixup_mac_addresses(u32 startindex, ...)
+{
+	va_list ap;
+	u32 index = startindex;
+	void *devp;
+	const u8 *addr;
+
+	va_start(ap, startindex);
+	while ((addr = va_arg(ap, const u8 *))) {
+		devp = find_node_by_prop_value(NULL, "linux,network-index",
+					       (void*)&index, sizeof(index));
+
+		printf("ENET%d: local-mac-address <-"
+		       " %02x:%02x:%02x:%02x:%02x:%02x\n\r", index,
+		       addr[0], addr[1], addr[2], addr[3], addr[4], addr[5]);
+
+		if (devp)
+			setprop(devp, "local-mac-address", addr, 6);
+
+		index++;
+	}
+	va_end(ap);
+}

[PATCH 3/4] powerpc: Clean up zImage handling of the command line

[David Gibson]

This patch cleans up how the zImage code manipulates the kernel
command line.  Notable improvements from the old handling:
	- Command line manipulation is consolidated into a new
prep_cmdline() function, rather than being scattered across start()
and some helper functions
	- Less stack space use: we use just a single global command
line buffer, which can be initialized by an external tool as before,
we no longer need another command line sized buffer on the stack.
	- Easier to support platforms whose firmware passes a
commandline, but not a device tree.  Platform code can now point new
loader_info fields to the firmware's command line, rather than having
to do early manipulation of the /chosen bootargs property which may
then be rewritten again by the core.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---

 arch/powerpc/boot/main.c |   52 +++++++++++++++++------------------------------
 arch/powerpc/boot/ops.h  |    2 +
 2 files changed, 21 insertions(+), 33 deletions(-)

Index: working-2.6/arch/powerpc/boot/main.c
===================================================================
--- working-2.6.orig/arch/powerpc/boot/main.c	2007-03-22 13:43:13.000000000 +1100
+++ working-2.6/arch/powerpc/boot/main.c	2007-03-22 13:46:52.000000000 +1100
@@ -204,31 +204,22 @@ static struct addr_range prep_initrd(str
  * edit the command line passed to vmlinux (by setting /chosen/bootargs).
  * The buffer is put in it's own section so that tools may locate it easier.
  */
-static char builtin_cmdline[COMMAND_LINE_SIZE]
+static char cmdline[COMMAND_LINE_SIZE]
 	__attribute__((__section__("__builtin_cmdline")));
 
-static void get_cmdline(char *buf, int size)
+static void prep_cmdline(void *chosen)
 {
-	void *devp;
-	int len = strlen(builtin_cmdline);
+	if (cmdline[0] == '\0')
+		getprop(chosen, "bootargs", cmdline, COMMAND_LINE_SIZE-1);
 
-	buf[0] = '\0';
+	printf("\n\rLinux/PowerPC load: %s", cmdline);
+	/* If possible, edit the command line */
+	if (console_ops.edit_cmdline)
+		console_ops.edit_cmdline(cmdline, COMMAND_LINE_SIZE);
+	printf("\n\r");
 
-	if (len > 0) { /* builtin_cmdline overrides dt's /chosen/bootargs */
-		len = min(len, size-1);
-		strncpy(buf, builtin_cmdline, len);
-		buf[len] = '\0';
-	}
-	else if ((devp = finddevice("/chosen")))
-		getprop(devp, "bootargs", buf, size);
-}
-
-static void set_cmdline(char *buf)
-{
-	void *devp;
-
-	if ((devp = finddevice("/chosen")))
-		setprop(devp, "bootargs", buf, strlen(buf) + 1);
+	/* Put the command line back into the devtree for the kernel */
+	setprop_str(chosen, "bootargs", cmdline);
 }
 
 struct platform_ops platform_ops;
@@ -240,10 +231,16 @@ void start(void *sp)
 {
 	struct addr_range vmlinux, initrd;
 	kernel_entry_t kentry;
-	char cmdline[COMMAND_LINE_SIZE];
 	unsigned long ft_addr = 0;
 	void *chosen;
 
+	/* Do this first, because malloc() could clobber the loader's
+	 * command line.  Only use the loader command line if a
+	 * built-in command line wasn't set by an external tool */
+	if ((loader_info.cmdline_len > 0) && (cmdline[0] == '\0'))
+		memmove(cmdline, loader_info.cmdline,
+			min(loader_info.cmdline_len, COMMAND_LINE_SIZE-1));
+
 	if (console_ops.open && (console_ops.open() < 0))
 		exit();
 	if (platform_ops.fixups)
@@ -260,18 +257,7 @@ void start(void *sp)
 	vmlinux = prep_kernel();
 	initrd = prep_initrd(vmlinux, chosen,
 			     loader_info.initrd_addr, loader_info.initrd_size);
-
-	/* If cmdline came from zimage wrapper or if we can edit the one
-	 * in the dt, print it out and edit it, if possible.
-	 */
-	if ((strlen(builtin_cmdline) > 0) || console_ops.edit_cmdline) {
-		get_cmdline(cmdline, COMMAND_LINE_SIZE);
-		printf("\n\rLinux/PowerPC load: %s", cmdline);
-		if (console_ops.edit_cmdline)
-			console_ops.edit_cmdline(cmdline, COMMAND_LINE_SIZE);
-		printf("\n\r");
-		set_cmdline(cmdline);
-	}
+	prep_cmdline(chosen);
 
 	printf("Finalizing device tree...");
 	if (dt_ops.finalize)
Index: working-2.6/arch/powerpc/boot/ops.h
===================================================================
--- working-2.6.orig/arch/powerpc/boot/ops.h	2007-03-22 13:43:13.000000000 +1100
+++ working-2.6/arch/powerpc/boot/ops.h	2007-03-22 13:45:26.000000000 +1100
@@ -70,6 +70,8 @@ struct serial_console_data {
 struct loader_info {
 	void *promptr;
 	unsigned long initrd_addr, initrd_size;
+	char *cmdline;
+	int cmdline_len;
 };
 extern struct loader_info loader_info;
 

[PATCH 4/4] powerpc: New reg.h for the zImage

[David Gibson]

This patch adds a reg.h to the zImage code, with common definitions
for accessing system reigsters.  For now, this includes functions for
retreiving the PVR and the stack pointer.  This patch then uses the
new reg.h to let start() display the running stack address without
having to explicitly pass the stack as a parameter from the asm code.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---

 arch/powerpc/boot/crt0.S |    1 -
 arch/powerpc/boot/main.c |    5 +++--
 arch/powerpc/boot/ops.h  |    2 +-
 arch/powerpc/boot/reg.h  |   22 ++++++++++++++++++++++
 4 files changed, 26 insertions(+), 4 deletions(-)

Index: working-2.6/arch/powerpc/boot/reg.h
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ working-2.6/arch/powerpc/boot/reg.h	2007-03-21 17:28:38.000000000 +1100
@@ -0,0 +1,22 @@
+#ifndef _PPC_BOOT_REG_H
+#define _PPC_BOOT_REG_H
+/*
+ * Copyright 2007 Davud Gibson, IBM Corporation.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+static inline u32 mfpvr(void)
+{
+	u32 pvr;
+	asm volatile ("mfpvr	%0" : "=r"(pvr));
+	return pvr;
+}
+
+register void *__stack_pointer asm("r1");
+#define get_sp()	(__stack_pointer)
+
+#endif	/* _PPC_BOOT_REG_H */
Index: working-2.6/arch/powerpc/boot/crt0.S
===================================================================
--- working-2.6.orig/arch/powerpc/boot/crt0.S	2007-03-21 17:24:48.000000000 +1100
+++ working-2.6/arch/powerpc/boot/crt0.S	2007-03-21 17:24:48.000000000 +1100
@@ -97,5 +97,4 @@ _zimage_start_lib:
 	bl	platform_init
 
 	/* Call start */
-	mr	r3,r1
 	b	start
Index: working-2.6/arch/powerpc/boot/main.c
===================================================================
--- working-2.6.orig/arch/powerpc/boot/main.c	2007-03-21 17:24:48.000000000 +1100
+++ working-2.6/arch/powerpc/boot/main.c	2007-03-21 17:24:48.000000000 +1100
@@ -17,6 +17,7 @@
 #include "ops.h"
 #include "gunzip_util.h"
 #include "flatdevtree.h"
+#include "reg.h"
 
 extern char _start[];
 extern char __bss_start[];
@@ -230,7 +231,7 @@ struct dt_ops dt_ops;
 struct console_ops console_ops;
 struct loader_info loader_info;
 
-void start(void *sp)
+void start(void)
 {
 	struct addr_range vmlinux, initrd;
 	kernel_entry_t kentry;
@@ -249,7 +250,7 @@ void start(void *sp)
 		platform_ops.fixups();
 
 	printf("\n\rzImage starting: loaded at 0x%p (sp: 0x%p)\n\r",
-	       _start, sp);
+	       _start, get_sp());
 
 	/* Ensure that the device tree has a /chosen node */
 	if (! finddevice("/chosen"))
Index: working-2.6/arch/powerpc/boot/ops.h
===================================================================
--- working-2.6.orig/arch/powerpc/boot/ops.h	2007-03-21 17:24:48.000000000 +1100
+++ working-2.6/arch/powerpc/boot/ops.h	2007-03-21 17:24:48.000000000 +1100
@@ -75,7 +75,7 @@ struct loader_info {
 };
 extern struct loader_info loader_info;
 
-void start(void *sp);
+void start(void);
 int ft_init(void *dt_blob, unsigned int max_size, unsigned int max_find_device);
 int serial_console_init(void);
 int ns16550_console_init(void *devp, struct serial_console_data *scdp);