PPC32: Kill off arch/ppc/boot/prep and rearrange some files.

arch/ppc/boot/Makefile

@@ -16,13 +16,12 @@ HOSTCFLAGS	+= -Iarch/$(ARCH)/boot/include
 BOOT_TARGETS	= zImage zImage.initrd znetboot znetboot.initrd
 
 bootdir-y			:= simple
-bootdir-$(CONFIG_PPC_OF)	:= openfirmware
-bootdir-$(CONFIG_PPC_PREP)	+= prep
+bootdir-$(CONFIG_PPC_OF)	+= openfirmware
 subdir-y			:= lib/ common/ images/
 subdir-$(CONFIG_PPC_OF)		+= of1275/
 
 # for cleaning
-subdir-				+= simple/ openfirmware/ prep/
+subdir-				+= simple/ openfirmware/
 
 host-progs := $(addprefix utils/, addnote mknote hack-coff mkprep mkbugboot mktree)
 

arch/ppc/boot/common/Makefile

@@ -9,8 +9,5 @@
 #
 
 lib-y					:= string.o util.o misc-common.o \
-						serial_stub.o
-lib-$(CONFIG_PPC_PREP)			+= mpc10x_memory.o
-lib-$(CONFIG_LOPEC)			+= mpc10x_memory.o
-lib-$(CONFIG_PAL4)			+= cpc700_memory.o
+						serial_stub.o bootinfo.o
 lib-$(CONFIG_SERIAL_8250_CONSOLE)	+= ns16550.o

arch/ppc/boot/common/util.S

@@ -14,7 +14,7 @@
  *	   trini@mvista.com
  * Derived from arch/ppc/boot/prep/head.S (Cort Dougan, many others).
  *
- * 2001-2003 (c) MontaVista, Software, Inc.  This file is licensed under
+ * 2001-2004 (c) MontaVista, Software, Inc.  This file is licensed under
  * the terms of the GNU General Public License version 2.  This program
  * is licensed "as is" without any warranty of any kind, whether express
  * or implied.
@@ -36,6 +36,13 @@ disable_6xx_mmu:
 	 */
 	li	r8,MSR_IP|MSR_FP
 	mtmsr	r8
+	isync
+
+	/* Test for a 601 */
+	mfpvr	r10
+	srwi	r10,r10,16
+	cmpi	0,r10,1		/* 601 ? */
+	beq	.clearbats_601
 
 	/* Clear BATs */
 	li	r8,0
@@ -47,6 +54,7 @@ disable_6xx_mmu:
 	mtspr	DBAT2L,r8
 	mtspr	DBAT3U,r8
 	mtspr	DBAT3L,r8
+.clearbats_601:
 	mtspr	IBAT0U,r8
 	mtspr	IBAT0L,r8
 	mtspr	IBAT1U,r8
@@ -68,6 +76,7 @@ disable_6xx_mmu:
 	addi	r8,r8,0x111	/* increment VSID */
 	addis	r10,r10,0x1000	/* address of next segment */
 	bdnz	3b
+	blr
 
 	.globl	disable_6xx_l1cache
 disable_6xx_l1cache:

arch/ppc/boot/lib/Makefile

@@ -2,4 +2,7 @@
 # Makefile for some libs needed by zImage.
 #
 
+CFLAGS_kbd.o	+= -Idrivers/char
+
 lib-y := zlib.o div64.o
+lib-$(CONFIG_VGA_CONSOLE) += vreset.o kbd.o

arch/ppc/boot/prep/Makefile

-# arch/ppc/boot/Makefile
-#
-# This file is subject to the terms and conditions of the GNU General Public
-# License.  See the file "COPYING" in the main directory of this archive
-# for more details.
-#
-# Tom Rini	January 2001
-#
-# Originally:
-# arch/ppc/boot/Makefile
-# Copyright (C) 1994 by Linus Torvalds
-# Adapted for PowerPC by Gary Thomas
-# modified by Cort (cort@cs.nmt.edu)
-#
-
-TFTPIMAGE		:= /tftpboot/zImage.prep
-ifeq ($(CONFIG_SMP),y)
-TFTPIMAGE		:= $(TFTPIMAGE).smp
-endif
-
-boot-y				:= head.o misc.o
-boot-$(CONFIG_VGA_CONSOLE)	+= vreset.o kbd.o
-
-boot	:= arch/ppc/boot
-common	:= $(boot)/common
-utils	:= $(boot)/utils
-bootlib	:= $(boot)/lib
-images	:= $(boot)/images
-simple	:= $(boot)/simple
-of1275	:= $(boot)/of1275
-
-OBJCOPYFLAGS	:= -O elf32-powerpc
-LIBS 		:= $(common)/lib.a $(bootlib)/lib.a $(of1275)/lib.a
-
-targets		:= $(boot-y) dummy.o ../simple/legacy.o
-OBJS		:= $(addprefix $(obj)/,$(boot-y)) $(simple)/legacy.o
-
-# Extra include search dirs
-CFLAGS_kbd.o			+= -Idrivers/char
-
-zImage: initrd :=
-zImage: $(images)/zImage.prep
-	@echo '  kernel: $@ is ready ($<)'
-
-zImage.initrd: initrd := .initrd
-zImage.initrd: $(images)/zImage.initrd.prep
-	@echo '  kernel: $@ is ready ($<)'
-
-$(images)/ramdisk.image.gz:
-	@echo '  MISSING $@'
-	@echo '          RAM disk image must be provided separately'
-	@/bin/false
-
-OBJCOPYFLAGS_image.o   := \
-	--add-section=.image=$(images)/vmlinux.gz \
-	--set-section-flags=.image=contents,alloc,load,readonly,data
-targets	+= image.o
-$(obj)/image.o: $(obj)/dummy.o $(images)/vmlinux.gz
-	$(call if_changed,objcopy)
-
-OBJCOPYFLAGS_image.initrd.o    := \
-	--add-section=.ramdisk=$(images)/ramdisk.image.gz \
-	--set-section-flags=.ramdisk=contents,alloc,load,readonly,data \
-	--add-section=.image=$(images)/vmlinux.gz \
-	--set-section-flags=.image=contents,alloc,load,readonly,data
-targets	+= image.initrd.o
-$(obj)/image.initrd.o: $(obj)/dummy.o $(images)/vmlinux.gz $(images)/ramdisk.image.gz
-	$(call if_changed,objcopy)
-
-LDFLAGS_zImage.bin		:= -Ttext 0x00800000 -Bstatic -T
-LDFLAGS_zImage.initrd.bin	:= -Ttext 0x00800000 -Bstatic -T
-targets += zImage.bin
-$(obj)/zImage.bin: $(boot)/ld.script $(OBJS) $(obj)/image.o $(LIBS)
-	$(call if_changed,ld)
-targets += zImage.initrd.bin
-$(obj)/zImage.initrd.bin: $(boot)/ld.script $(OBJS) $(obj)/image.initrd.o $(LIBS)
-	$(call if_changed,ld)
-
-OBJCOPYFLAGS_zImage		:= -R .comment -R .stab -R .stabstr
-OBJCOPYFLAGS_zImage.initrd	:= -R .comment -R .stab -R .stabstr
-targets += zImage
-$(obj)/zImage: %: %.bin FORCE
-	$(call if_changed,objcopy)
-targets += zImage.initrd
-$(obj)/zImage.initrd: %: %.bin FORCE
-	$(call if_changed,objcopy)
-
-quiet_cmd_mkprep = MKPREP  $@
-      cmd_mkprep = $(utils)/mkprep -pbp $< $@
-
-$(images)/zImage.prep: $(obj)/zImage $(utils)/mkprep
-	$(call cmd,mkprep)
-$(images)/zImage.initrd.prep: $(obj)/zImage.initrd $(utils)/mkprep
-	$(call cmd,mkprep)
-
-#
-# Convinient shorthands for various targets
-#
-floppy: zImage
-	dd if=$(images)/zImage.prep of=/dev/fd0H1440 bs=64b
-
-znetboot : zImage
-	cp $(images)/zImage.prep $(TFTPIMAGE)
-	@echo '  kernel: $@ is ready ($<)'
-
-znetboot.initrd : zImage.initrd
-	cp $(images)/zImage.initrd.prep $(TFTPIMAGE)
-	@echo '  kernel: $@ is ready ($<)'
-

arch/ppc/boot/prep/dummy.c

-int main(void)
-{
-	return 0;
-}

arch/ppc/boot/prep/head.S

-#include <asm/ppc_asm.h>
-#include <asm/reg.h>
-#include <asm/cache.h>
-
-	.text
-
-/*
- * Boot loader philosophy:
- *      ROM loads us to some arbitrary location
- *      Move the boot code to the link address (8M)
- *      Call decompress_kernel()
- *         Relocate the initrd, zimage and residual data to 8M
- *         Decompress the kernel to 0
- *      Jump to the kernel entry
- *            -- Cort
- */
-	.globl	start
-start:
-	bl	start_
-start_:
-
-        /* Enable, invalidate, Disable L1 icache/dcache */
-	li	r8, 0
-	ori	r8, r8, (HID0_ICE|HID0_DCE|HID0_ICFI|HID0_DCI)
-	mfspr	r11,HID0
-	or	r11,r11,r8
-	andc	r10,r11,r8
-	isync
-	mtspr	HID0,r8
-	sync
-	isync
-	mtspr	HID0,r10
-	sync
-	isync
-
-	mr	r11,r3		/* Save pointer to residual/board data */
-
-/*
- * Save the OF pointer to r25, but only if the entry point is in a sane
- * location; if not we store 0.  If there is no entry point, or it is
- * invalid, we establish the default MSR value immediately.  Otherwise,
- * we defer doing that, to allow OF functions to be called, until we
- * begin uncompressing the kernel.
- */
-	lis	r3,0x0fff		/* r3 = 0x0fffffff */
-	ori	r3,r3,0xffff
-
-	subc	r3,r3,r5		/* r3 = (r5 <= r3) ? ~0 : 0 */
-	subfe	r3,r3,r3
-	nand	r3,r3,r3
-
-	and.	r5,r5,r3		/* r5 will be cleared if (r5 > r3) */
-	bne+	haveOF
-
-	li	r3,MSR_IP|MSR_FP	/* Not OF: set MSR immediately */
-  	mtmsr	r3
-	isync
-haveOF:
-	mr	r25,r5
-
-	/* compute the size of the whole image in words. */
-	lis	r4,start@h
-	ori	r4,r4,start@l
-	lis	r5,end@h
-	ori	r5,r5,end@l
-	addi	r5,r5,3		/* round up */
-	sub	r5,r5,r4	/* end - start */
-	srwi	r5,r5,2
-	mr	r7,r5		/* Save for later use. */
-
-	/* check if we need to relocate ourselves to the link addr or were
-	 * we loaded there to begin with -- Cort */
-	mflr	r3
-	subi	r3,r3,4		/* we get the nip, not the ip of the branch */
-	mr	r8,r3
-	cmp	0,r3,r4
-	beq	start_ldr	/* If 0, we don't need to relocate */
-/*
- * no matter where we're loaded, move ourselves to -Ttext address
- */
-relocate:
-	mflr	r3		/* Compute code bias */
-	subi	r3,r3,4
-	mr	r8,r3
-	lis	r4,start@h
-	ori	r4,r4,start@l
-	mr	r5,r7		/* Get the # of longwords again */
-	mtctr	r5		/* Setup for loop */
-	li	r6,0
-	subi	r3,r3,4
-	subi	r4,r4,4
-00:	lwzu	r5,4(r3)
-	stwu	r5,4(r4)
-	xor	r6,r6,r5
-	bdnz	00b
-  	lis	r3,start_ldr@h
-	ori	r3,r3,start_ldr@l
-	mtlr	r3		/* Easiest way to do an absolute jump */
-	blr
-
-start_ldr:
-/* Some boards don't boot up with the I-cache enabled.  Do that
- * now because the decompress runs much faster that way.
- * As a side effect, we have to ensure the data cache is not enabled
- * so we can access the serial I/O without trouble.
- */
-	bl	flush_instruction_cache
-
-/* Clear all of BSS */
-	lis	r3,edata@h
-	ori	r3,r3,edata@l
-	lis	r4,end@h
-	ori	r4,r4,end@l
-	subi	r3,r3,4
-	subi	r4,r4,4
-	li	r0,0
-50:	stwu	r0,4(r3)
-	cmp	0,r3,r4
-	bne	50b
-90:	mr	r9,r1			/* Save old stack pointer (in case it matters) */
-	lis	r1,.stack@h
-	ori	r1,r1,.stack@l
-	addi	r1,r1,4096*2
-	subi	r1,r1,256
-	li	r2,0x000F		/* Mask pointer to 16-byte boundary */
-	andc	r1,r1,r2
-
-/* Run loader */
-	mr	r3,r8			/* Load point */
-	mr	r4,r7			/* Program length */
-	mr	r5,r6			/* Checksum */
-	mr	r6,r11			/* Residual data */
-	mr      r7,r25                  /* Validated OFW interface */
-	bl	decompress_kernel
-
-	/*
-	 * We have to do this after decompress_kernel, just to make
-	 * sure we don't wipe out things mapped in BATs which we need.
-	 * -- Tom
-	 */
-	li      r6,0
-	/* Test for a 601 */
-	mfspr	r9,PVR
-	srwi	r9,r9,16
-	cmpi	0,r9,1          /* 601 ? */
-	beq	.clearbats_601
-
-	/* Clear BATS */
-	mtspr   DBAT0U,r6
-	mtspr	DBAT0L,r6
-	mtspr   DBAT1U,r6
-	mtspr	DBAT1L,r6
-	mtspr   DBAT2U,r6
-	mtspr	DBAT2L,r6
-	mtspr   DBAT3U,r6
-	mtspr	DBAT3L,r6
-.clearbats_601:
-	mtspr   IBAT0U,r6
-	mtspr	IBAT0L,r6
-	mtspr   IBAT1U,r6
-	mtspr	IBAT1L,r6
-	mtspr	IBAT2U,r6
-	mtspr   IBAT2L,r6
-	mtspr   IBAT3U,r6
-	mtspr	IBAT3L,r6
-	isync
-	sync
-	sync
-
-	/* Set segment registers */
-	li	r6,16		/* load up segment register values */
-	mtctr	r6		/* for context 0 */
-	lis	r6,0x2000	/* Ku = 1, VSID = 0 */
-	li	r10,0
-3:	mtsrin	r6,r10
-	addi	r6,r6,0x111	/* increment VSID */
-	addis	r10,r10,0x1000	/* address of next segment */
-	bdnz	3b
-
-	/* tell kernel we're prep, by putting 0xdeadc0de at KERNELLOAD,
-	 * and tell the kernel to start on the 4th instruction since we
-	 * overwrite the first 3 sometimes (which are 'nop').
-	 */
-	li	r9,0xc
-	mtlr	r9
-	lis	r10,0xdeadc0de@h
-	ori	r10,r10,0xdeadc0de@l
-	li	r9,0
-	stw	r10,0(r9)
-	blr
-
-	.comm	.stack,4096*2,4

arch/ppc/boot/simple/Makefile

@@ -26,11 +26,12 @@ common				:= $(boot)/common
 utils				:= $(boot)/utils
 bootlib				:= $(boot)/lib
 images				:= $(boot)/images
+of1275				:= $(boot)/of1275
 tftpboot			:= /tftpboot
 
 # Normally, we use the 'misc.c' file for decompress_kernel and
 # whatnot.  Sometimes we need to override this however.
-misc-y	:= misc.o ../common/bootinfo.o
+misc-y	:= misc.o
 
 # Normally, we have our images end in .elf, but something we want to
 # change this.
@@ -89,6 +90,7 @@ zimageinitrd-$(motorola)		:= zImage.initrd-PPLUS
 
 # Overrides previous assingment
      extra.o-$(CONFIG_PPLUS)		:= legacy.o
+     extra.o-$(CONFIG_LOPEC)		:= mpc10x_memory.o
 
       zimage-$(pcore)			:= zImage-STRIPELF
 zimageinitrd-$(pcore)			:= zImage.initrd-STRIPELF
@@ -96,6 +98,12 @@ zimageinitrd-$(pcore)			:= zImage.initrd-STRIPELF
          end-$(pcore)			:= pcore
    cacheflag-$(pcore)			:= -include $(clear_L2_L3)
 
+      zimage-$(CONFIG_PPC_PREP)		:= zImage-PPLUS
+zimageinitrd-$(CONFIG_PPC_PREP)		:= zImage.initrd-PPLUS
+     extra.o-$(CONFIG_PPC_PREP)		:= legacy.o
+        misc-$(CONFIG_PPC_PREP)		+= misc-prep.o mpc10x_memory.o
+         end-$(CONFIG_PPC_PREP)		:= prep
+
          end-$(CONFIG_SANDPOINT)	:= sandpoint
    cacheflag-$(CONFIG_SANDPOINT)	:= -include $(clear_L2_L3)
 
@@ -138,6 +146,9 @@ boot-$(CONFIG_GT64260_CONSOLE)	+= gt64260_tty.o
 endif
 
 LIBS				:= $(common)/lib.a $(bootlib)/lib.a
+ifeq ($(CONFIG_PPC_PREP),y)
+LIBS 				+= $(of1275)/lib.a
+endif
 
 OBJS				:= $(addprefix $(obj)/,$(boot-y))
 
@@ -199,10 +210,10 @@ $(images)/zImage.initrd-TREE: $(obj)/zvmlinux.initrd $(MKTREE)
 	$(MKTREE) $(obj)/zvmlinux.initrd $(images)/zImage.initrd.$(end-y) \
 		$(ENTRYPOINT)
 
-$(images)/zImage-PPLUS: $(obj)/zvmlinux $(MKPREP) $(MKBUGBOOT)
-	$(MKPREP) -pbp $(obj)/zvmlinux $(images)/zImage.pplus
+$(images)/zImage-PPLUS: $(obj)/zvmlinux $(utils)/mkprep $(MKBUGBOOT)
+	$(MKPREP) -pbp $(obj)/zvmlinux $(images)/zImage.$(end-y)
 	$(MKBUGBOOT) $(obj)/zvmlinux $(images)/zImage.bugboot
 
-$(images)/zImage.initrd-PPLUS: $(obj)/zvmlinux.initrd $(MKPREP) $(MKBUGBOOT)
-	$(MKPREP) -pbp $(obj)/zvmlinux.initrd $(images)/zImage.initrd.pplus
+$(images)/zImage.initrd-PPLUS: $(obj)/zvmlinux.initrd $(utils)/mkprep $(MKBUGBOOT)
+	$(MKPREP) -pbp $(obj)/zvmlinux.initrd $(images)/zImage.initrd.$(end-y)
 	$(MKBUGBOOT) $(obj)/zvmlinux.initrd $(images)/zImage.initrd.bugboot

arch/ppc/boot/simple/head.S

@@ -7,7 +7,7 @@
  *	   trini@mvista.com
  * Derived from arch/ppc/boot/prep/head.S (Cort Dougan, many others).
  *
- * 2001-2003 (c) MontaVista, Software, Inc.  This file is licensed under
+ * 2001-2004 (c) MontaVista, Software, Inc.  This file is licensed under
  * the terms of the GNU General Public License version 2.  This program
  * is licensed "as is" without any warranty of any kind, whether express
  * or implied.
@@ -57,10 +57,11 @@ start_:
 	isync
 #endif
 
-#if defined(CONFIG_MBX) || defined(CONFIG_RPX6)
+#if defined(CONFIG_MBX) || defined(CONFIG_RPX6) || defined(CONFIG_PPC_PREP)
 	mr	r29,r3	/* On the MBX860, r3 is the board info pointer.
-			 * On the RPXSUPER, r3 points to the
-			 * NVRAM configuration keys.
+			 * On the RPXSUPER, r3 points to the NVRAM
+			 * configuration keys.
+			 * On PReP, r3 is the pointer to the residual data.
 			 */
 #endif
 
@@ -69,7 +70,36 @@ start_:
 	/* The following functions we call must not modify r3 or r4.....
 	*/
 #ifdef CONFIG_6xx
+	/* On PReP we must look at the OpenFirmware pointer and sanity
+	 * test it.  On other platforms, we disable the MMU right now
+	 * and other bits.
+	 */
+#ifdef CONFIG_PPC_PREP
+/*
+ * Save the OF pointer to r25, but only if the entry point is in a sane
+ * location; if not we store 0.  If there is no entry point, or it is
+ * invalid, we establish the default MSR value immediately.  Otherwise,
+ * we defer doing that, to allow OF functions to be called, until we
+ * begin uncompressing the kernel.
+ */
+	lis	r8,0x0fff		/* r8 = 0x0fffffff */
+	ori	r8,r8,0xffff
+
+	subc	r8,r8,r5		/* r8 = (r5 <= r8) ? ~0 : 0 */
+	subfe	r8,r8,r8
+	nand	r8,r8,r8
+
+	and.	r5,r5,r8		/* r5 will be cleared if (r5 > r8) */
+	bne+	haveOF
+
+	li	r8,MSR_IP|MSR_FP	/* Not OF: set MSR immediately */
+  	mtmsr	r8
+	isync
+haveOF:
+	mr	r25,r5
+#else
 	bl	disable_6xx_mmu
+#endif
 	bl	disable_6xx_l1cache
 
 	CLEAR_CACHES
@@ -99,7 +129,7 @@ start_:
 	mr	r3, r29
 #endif
 
-#if defined(CONFIG_MBX) || defined(CONFIG_RPX6)
+#if defined(CONFIG_MBX) || defined(CONFIG_RPX6) || defined(CONFIG_PPC_PREP)
 	mr	r4,r29	/* put the board info pointer where the relocate
 			 * routine will find it
 			 */

arch/ppc/boot/simple/misc-spruce.c

@@ -174,7 +174,8 @@ get_mem_size(void)
 }
 
 unsigned long
-load_kernel(unsigned long load_addr, int num_words, unsigned long cksum)
+load_kernel(unsigned long load_addr, int num_words, unsigned long cksum,
+		void *ign1, void *ign2)
 {
 	int csr0;
 	int csr_id;

arch/ppc/boot/simple/misc.c

@@ -99,7 +99,9 @@ decompress_kernel(unsigned long load_addr, int num_words, unsigned long cksum)
 	unsigned long initrd_loc, TotalMemory = 0;
 
 	serial_fixups();
+#ifdef CONFIG_SERIAL_8250_CONSOLE
 	com_port = serial_init(0, NULL);
+#endif
 
 #ifdef CONFIG_44x
 	/* Reset MAL */
@@ -269,7 +271,8 @@ decompress_kernel(unsigned long load_addr, int num_words, unsigned long cksum)
 
 /* Allow decompress_kernel to be hooked into.  This is the default. */
 void * __attribute__ ((weak))
-load_kernel(unsigned long load_addr, int num_words, unsigned long cksum)
+load_kernel(unsigned long load_addr, int num_words, unsigned long cksum,
+		void *ign1, void *ign2)
 {
 		return decompress_kernel(load_addr, num_words, cksum);
 }

arch/ppc/boot/common/mpc10x_memory.c → arch/ppc/boot/simple/mpc10x_memory.c

@@ -52,8 +52,12 @@ MPC10X_PCI_OP(read, dword, u32 *, in_le32, 0)
  * the system.  This assumes that the firmware has correctly set up the memory
  * controller registers.  On CONFIG_PPC_PREP, we know we are being called
  * under a PReP memory map. On all other machines, we assume we are under
- * a CHRP memory map.
+ * a CHRP memory map.  Further, on CONFIG_PPC_MULTIPLATFORM we must rename
+ * this function.
  */
+#ifdef CONFIG_PPC_MULTIPLATFORM
+#define get_mem_size mpc10x_get_mem_size
+#endif
 unsigned long
 get_mem_size(void)
 {

arch/ppc/boot/simple/relocate.S

@@ -9,7 +9,7 @@
  *	   trini@mvista.com
  * Derived from arch/ppc/boot/prep/head.S (Cort Dougan, many others).
  *
- * 2001-2002 (c) MontaVista, Software, Inc.  This file is licensed under
+ * 2001-2004 (c) MontaVista, Software, Inc.  This file is licensed under
  * the terms of the GNU General Public License version 2.  This program
  * is licensed "as is" without any warranty of any kind, whether express
  * or implied.
@@ -102,7 +102,7 @@ relocate:
 	GETSYM(r5, do_relocate)
 
 	sub	r4,r5,r4	/* Get entry point for do_relocate in
-	add	r6,r6,r4       * relocated section */
+	add	r6,r6,r4	* relocated section */
 
 	/* This will return to the relocated do_relocate */
 	mtlr	r6
@@ -182,6 +182,7 @@ start_ldr:
 	mr	r4,r7		/* Program length */
 	mr	r5,r6		/* Checksum */
 	mr	r6,r11		/* Residual data */
+	mr	r7,r25		/* Validated OFW interface */
 	bl	load_kernel
 
 	/*
@@ -195,8 +196,18 @@ start_ldr:
 	/*
 	 * Start at the begining.
 	 */
-	li	r9,0x0000
+	li	r9,0xc
 	mtlr	r9
+#ifdef CONFIG_PPC_MULTIPLATFORM
+	/* tell kernel we're prep, by putting 0xdeadc0de at KERNELLOAD,
+	 * and tell the kernel to start on the 4th instruction since we
+	 * overwrite the first 3 sometimes (which are 'nop').
+	 */
+	lis	r10,0xdeadc0de@h
+	ori	r10,r10,0xdeadc0de@l
+	li	r9,0
+	stw	r10,0(r9)
+#endif
 	blr
 
 	.comm	.stack,4096*2,4