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authorRalf Baechle <ralf@linux-mips.org>1999-06-13 16:29:25 +0000
committerRalf Baechle <ralf@linux-mips.org>1999-06-13 16:29:25 +0000
commitdb7d4daea91e105e3859cf461d7e53b9b77454b2 (patch)
tree9bb65b95440af09e8aca63abe56970dd3360cc57 /arch/ppc/boot/head.S
parent9c1c01ead627bdda9211c9abd5b758d6c687d8ac (diff)
Merge with Linux 2.2.8.
Diffstat (limited to 'arch/ppc/boot/head.S')
-rw-r--r--arch/ppc/boot/head.S116
1 files changed, 26 insertions, 90 deletions
diff --git a/arch/ppc/boot/head.S b/arch/ppc/boot/head.S
index 43facf7e2..552e82fa1 100644
--- a/arch/ppc/boot/head.S
+++ b/arch/ppc/boot/head.S
@@ -1,4 +1,3 @@
-#include <linux/config.h>
#include "../kernel/ppc_defs.h"
#include "../kernel/ppc_asm.tmpl"
#include <asm/processor.h>
@@ -7,43 +6,24 @@
.text
/*
- * $Id: head.S,v 1.26 1998/09/19 01:21:20 cort Exp $
+ * $Id: head.S,v 1.31 1999/04/22 06:32:00 davem Exp $
*
- * This code is loaded by the ROM loader at some arbitrary location.
- * Move it to high memory so that it can load the kernel at 0x0000.
- *
- * The MBX EPPC-Bug understands ELF, so it loads us into the location
- * specified in the header. This is a two step process. First, EPPC-Bug
- * loads the file into the intermediate buffer memory location specified
- * by the environment parameters. When it discovers this is an ELF
- * binary, it relocates to the link address for us. Unfortunately, the
- * header does not move with the file, so we have to find the
- * intermediate load location and read the header from there. From
- * information provided by Motorola (thank you), we know this intermediate
- * location can be found from the NVRAM environment.
- * All of these addresses must be somewhat carefully chosen to make sure
- * we don't overlap the regions. I chose to load the kernel at 0, the
- * compressed image loads at 0x00100000, and the MBX intermediate buffer
- * was set to 0x00200000. Provided the loaded kernel image never grows
- * over one megabyte (which I am going to ensure never happens :-), these
- * will work fine. When we get called from EPPC-Bug, registers are:
- * R1 - Stack pointer at a high memory address.
- * R3 - Pointer to Board Information Block.
- * R4 - Pointer to argument string.
- * Interrupts masked, cache and MMU disabled.
+ * 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_:
mr r11,r3 /* Save pointer to residual/board data */
-
-#ifndef CONFIG_MBX
- mfmsr r3 /* Turn off interrupts */
- li r4,0
- ori r4,r4,MSR_EE
- andc r3,r3,r4
+ mr r25,r5 /* Save OFW pointer */
+ li r3,MSR_IP /* Establish default MSR value */
mtmsr r3
/* check if we need to relocate ourselves to the link addr or were we
@@ -68,25 +48,6 @@ start_:
mr r7,r5
b start_ldr
1010:
-#if 0
-/* Copy relocation code down to location 0x0100 (where we hope it's safe!) */
- mflr r3
- addi r5,r3,start_ldr-start_
- addi r3,r3,relocate-start_
- li r4,0x0100
- mtctr r4
- subi r3,r3,4
- subi r4,r4,4
-00: lwzu r6,4(r3)
- stwu r6,4(r4)
- cmp 0,r3,r5
- bne 00b
- mflr r21
- mfctr r22
- mtlr r21
- mtctr r22
- bctr /* Jump to code */
-#endif
/*
* no matter where we're loaded, move ourselves to -Ttext address
*/
@@ -96,13 +57,8 @@ relocate:
mr r8,r3
lis r4,start@h
ori r4,r4,start@l
-#if 0
- lis r5,edata@h
- ori r5,r5,edata@l
-#else
lis r5,end@h
ori r5,r5,end@l
-#endif
addi r5,r5,3 /* Round up - just in case */
sub r5,r5,r4 /* Compute # longwords to move */
srwi r5,r5,2
@@ -120,7 +76,6 @@ relocate:
mtlr r3 /* Easiest way to do an absolute jump */
blr
start_ldr:
-#endif /* ndef CONFIG_MBX */
/* Clear all of BSS */
lis r3,edata@h
ori r3,r3,edata@l
@@ -140,31 +95,11 @@ start_ldr:
li r2,0x000F /* Mask pointer to 16-byte boundary */
andc r1,r1,r2
/* Run loader */
-#ifdef CONFIG_MBX
- mr r3, r11
- mr r21, r11
- bl serial_init /* Init MBX serial port */
-
- lis r8, 0xfa200000@h /* Disable Ethernet SCC */
- li r0, 0
- stw r0, 0x0a00(r8)
-
- mr r11, r21
- lis r8,start@h
- ori r8,r8,start@l
- li r9,end@h
- ori r9,r9,end@l
- sub r7,r8,r9
- srwi r7,r7,2
-#define ILAP_ADDRESS 0xfa000020
- lis r8, ILAP_ADDRESS@h
- lwz r8, ILAP_ADDRESS@l(r8)
- addis r8, r8, 1 /* Add 64K */
-#endif
mr r3,r8 /* Load point */
mr r4,r7 /* Program length */
mr r5,r6 /* Checksum */
mr r6,r11 /* Residual data */
+ mr r7,r25 /* OFW interfaces */
bl decompress_kernel
/* changed to use r3 (as firmware does) for kernel
@@ -193,12 +128,24 @@ start_ldr:
li r9,0x0
lwz r9,0(r9)
mtlr r9
-#ifndef CONFIG_MBX
li r9,0
lis r10,0xdeadc0de@h
ori r10,r10,0xdeadc0de@l
stw r10,0(r9)
-#endif
+/*
+ * The Radstone firmware maps PCI memory at 0xc0000000 using BAT2
+ * so disable BATs before setting this to avoid a clash
+ */
+ li r8,0
+ mtspr DBAT0U,r8
+ mtspr DBAT1U,r8
+ mtspr DBAT2U,r8
+ mtspr DBAT3U,r8
+ mtspr IBAT0U,r8
+ mtspr IBAT1U,r8
+ mtspr IBAT2U,r8
+ mtspr IBAT3U,r8
+
blr
hang:
b hang
@@ -269,7 +216,6 @@ _put_MSR:
_GLOBAL(flush_instruction_cache)
mflr r5
bl flush_data_cache
-#ifndef CONFIG_MBX
mfspr r3,HID0 /* Caches are controlled by this register */
li r4,0
ori r4,r4,(HID0_ICE|HID0_ICFI)
@@ -278,18 +224,12 @@ _GLOBAL(flush_instruction_cache)
andc r3,r3,r4
ori r3,r3,HID0_ICE /* Enable cache */
mtspr HID0,r3
-#endif
mtlr r5
blr
#define NUM_CACHE_LINES 128*8
#define CACHE_LINE_SIZE 32
-#if 0
-cache_flush_buffer:
- .space NUM_CACHE_LINES*CACHE_LINE_SIZE /* CAUTION! these need to match hardware */
-#else
#define cache_flush_buffer 0x1000
-#endif
/*
* Flush data cache
@@ -300,11 +240,7 @@ _GLOBAL(flush_data_cache)
ori r3,r3,cache_flush_buffer@l
li r4,NUM_CACHE_LINES
mtctr r4
-#if 0
-00: dcbz 0,r3 /* Flush cache line with minimal BUS traffic */
-#else
00: lwz r4,0(r3)
-#endif
addi r3,r3,CACHE_LINE_SIZE /* Next line, please */
bdnz 00b
10: blr