patch-2.4.2 linux/arch/cris/boot/compressed/head.S

• Lines: 101
• Date: Thu Feb 8 16:32:44 2001
• Orig file: v2.4.1/linux/arch/cris/boot/compressed/head.S
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.1/linux/arch/cris/boot/compressed/head.S linux/arch/cris/boot/compressed/head.S
@@ -0,0 +1,100 @@
+/*
+ *  arch/etrax100/boot/compressed/head.S
+ *
+ *  Copyright (C) 1999 Axis Communications AB
+ *
+ *  Code that sets up the DRAM registers, calls the
+ *  decompressor to unpack the piggybacked kernel, and jumps.
+ *
+ */
+
+#include <linux/config.h>
+#define ASSEMBLER_MACROS_ONLY
+#include <asm/sv_addr_ag.h>
+
+	;; Exported symbols
+	
+	.globl	_input_data
+
+	
+	.text
+
+	nop
+	di
+
+#ifndef CONFIG_SVINTO_SIM	
+
+	;; We need to setup the bus registers before we start using the DRAM
+
+	move.d   DEF_R_WAITSTATES, r0
+	move.d   r0, [R_WAITSTATES]
+
+	move.d   DEF_R_BUS_CONFIG, r0
+	move.d   r0, [R_BUS_CONFIG]
+  
+	move.d   DEF_R_DRAM_CONFIG, r0
+	move.d   r0, [R_DRAM_CONFIG]
+
+	move.d   DEF_R_DRAM_TIMING, r0
+	move.d   r0, [R_DRAM_TIMING]
+
+#endif
+
+	;; Setup the stack to a suitably high address.
+	;; We assume 8 MB is the minimum DRAM in an eLinux
+	;; product and put the sp at the top for now.
+
+	move.d	0x40800000, sp
+
+	;; Figure out where the compressed piggyback image is
+	;; in the flash (since we wont try to copy it to DRAM
+	;; before unpacking). It is at _edata, but in flash.
+	;; Use (_edata - basse) as offset to the current PC.
+	
+basse:	move.d	pc, r5
+	and.d	0x7fffffff, r5	; strip any non-cache bit
+	subq	2, r5		; compensate for the move.d pc instr
+	move.d	r5, r0		; save for later - flash address of 'basse'
+	add.d	_edata, r5
+	sub.d	basse, r5	; r5 = flash address of '_edata'
+	
+	;; Copy text+data to DRAM
+	
+	move.d	basse, r1	; destination
+	move.d	_edata, r2	; end destination
+1:	move.w	[r0+], r3
+	move.w	r3, [r1+]
+	cmp.d	r2, r1
+	bcs	1b
+	nop
+
+	move.d	r5, [_input_data] ; for the decompressor
+
+	;; Clear the decompressors BSS (between _edata and _end)
+	
+	moveq	0, r0
+	move.d	_edata, r1
+	move.d	_end, r2
+1:	move.w	r0, [r1+]
+	cmp.d	r2, r1
+	bcs	1b
+	nop
+	
+	;; Do the decompression and save compressed size in _inptr
+	
+	jsr	_decompress_kernel
+
+	;; Put start address of cramfs in r9 so the kernel can use it
+	;; when mounting from flash
+
+	move.d	[_input_data], r9	; flash address of compressed kernel
+	add.d	[_inptr], r9		; size of compressed kernel
+
+	;; Enter the decompressed kernel
+		
+	jump	0x40004000	; kernel is linked to this address
+	
+	.data
+
+_input_data:
+	.dword	0		; used by the decompressor