From: Tom Rini <trini@kernel.crashing.org>
Re-add support to the bootwrapper for talking with OF on PReP machines.
This fixes memory detection of some machines.
---
arch/ppc/boot/prep/Makefile | 3 +-
arch/ppc/boot/prep/head.S | 26 +++++++++++++++++++---
arch/ppc/boot/prep/misc.c | 52 ++++++++++++++++++++++++++++++++++++++------
3 files changed, 70 insertions(+), 11 deletions(-)
diff -puN arch/ppc/boot/prep/head.S~ppc32-of-bootwrapper-support arch/ppc/boot/prep/head.S
--- 25/arch/ppc/boot/prep/head.S~ppc32-of-bootwrapper-support 2004-01-08 10:47:25.000000000 -0800
+++ 25-akpm/arch/ppc/boot/prep/head.S 2004-01-08 10:47:25.000000000 -0800
@@ -35,9 +35,28 @@ start_:
mr r11,r3 /* Save pointer to residual/board data */
- /* Establish default MSR value */
- li r3,MSR_IP|MSR_FP
- mtmsr r3
+/*
+ * 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
@@ -111,6 +130,7 @@ start_ldr:
mr r4,r7 /* Program length */
mr r5,r6 /* Checksum */
mr r6,r11 /* Residual data */
+ mr r7,r25 /* Validated OFW interface */
bl decompress_kernel
/*
diff -puN arch/ppc/boot/prep/Makefile~ppc32-of-bootwrapper-support arch/ppc/boot/prep/Makefile
--- 25/arch/ppc/boot/prep/Makefile~ppc32-of-bootwrapper-support 2004-01-08 10:47:25.000000000 -0800
+++ 25-akpm/arch/ppc/boot/prep/Makefile 2004-01-08 10:47:25.000000000 -0800
@@ -27,9 +27,10 @@ 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
+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
diff -puN arch/ppc/boot/prep/misc.c~ppc32-of-bootwrapper-support arch/ppc/boot/prep/misc.c
--- 25/arch/ppc/boot/prep/misc.c~ppc32-of-bootwrapper-support 2004-01-08 10:47:25.000000000 -0800
+++ 25-akpm/arch/ppc/boot/prep/misc.c 2004-01-08 10:47:25.000000000 -0800
@@ -19,7 +19,7 @@
#include <asm/bootinfo.h>
#include <asm/mmu.h>
#include <asm/byteorder.h>
-
+#include "of1275.h"
#include "nonstdio.h"
#include "zlib.h"
@@ -114,17 +114,19 @@ scroll(void)
unsigned long
decompress_kernel(unsigned long load_addr, int num_words, unsigned long cksum,
- RESIDUAL *residual)
+ RESIDUAL *residual, void *OFW_interface)
{
int timer = 0;
extern unsigned long start;
char *cp, ch;
unsigned long TotalMemory;
- unsigned char board_type;
- unsigned char base_mod;
int start_multi = 0;
unsigned int pci_viddid, pci_did, tulip_pci_base, tulip_base;
+ /* If we have Open Firmware, initialise it immediately */
+ if (OFW_interface)
+ ofinit(OFW_interface);
+
serial_fixups();
#if defined(CONFIG_SERIAL_8250_CONSOLE)
com_port = serial_init(0, NULL);
@@ -163,7 +165,8 @@ decompress_kernel(unsigned long load_add
/* Is this Motorola PPCBug? */
if ((1 & residual->VitalProductData.FirmwareSupports) &&
(1 == residual->VitalProductData.FirmwareSupplier)) {
- board_type = inb(0x800) & 0xF0;
+ unsigned char base_mod;
+ unsigned char board_type = inb(0x800) & 0xF0;
/*
* Reset the onboard 21x4x Ethernet
@@ -229,8 +232,31 @@ decompress_kernel(unsigned long load_add
/* If it's not, see if we have anything in the residual data. */
else if (residual && residual->TotalMemory)
TotalMemory = residual->TotalMemory;
- /* Fall back to hard-coding 32MB. */
- else
+ else if (OFW_interface) {
+ /*
+ * This is a 'best guess' check. We want to make sure
+ * we don't try this on a PReP box without OF
+ * -- Cort
+ */
+ while (OFW_interface)
+ {
+ phandle dev_handle;
+ int mem_info[2];
+
+ /* get handle to memory description */
+ if (!(dev_handle = finddevice("/memory@0")))
+ break;
+
+ /* get the info */
+ if (getprop(dev_handle, "reg", mem_info,
+ sizeof(mem_info)) != 8)
+ break;
+
+ TotalMemory = mem_info[1];
+ break;
+ }
+ } else
+ /* Fall back to hard-coding 32MB. */
TotalMemory = 32*1024*1024;
@@ -304,6 +330,18 @@ decompress_kernel(unsigned long load_add
*cp = 0;
puts("\nUncompressing Linux...");
+ /*
+ * If we have OF, then we have deferred setting the MSR.
+ * We must set it now because we are about to overwrite
+ * the exception table. The new MSR value will disable
+ * machine check exceptions and point the exception table
+ * to the ROM.
+ */
+ if (OFW_interface) {
+ mtmsr(MSR_IP | MSR_FP);
+ asm volatile("isync");
+ }
+
gunzip(0, 0x400000, zimage_start, &zimage_size);
puts("done.\n");
_