1/*
2 *  arch/cris/boot/compressed/head.S
3 *
4 *  Copyright (C) 1999, 2001 Axis Communications AB
5 *
6 *  Code that sets up the DRAM registers, calls the
7 *  decompressor to unpack the piggybacked kernel, and jumps.
8 *
9 */
10
11#define ASSEMBLER_MACROS_ONLY
12#include <arch/sv_addr_ag.h>
13
14#define RAM_INIT_MAGIC 0x56902387
15#define COMMAND_LINE_MAGIC 0x87109563
16
17	;; Exported symbols
18
19	.globl	input_data
20
21
22	.text
23
24	nop
25	di
26
27;; We need to initialze DRAM registers before we start using the DRAM
28
29	cmp.d	RAM_INIT_MAGIC, $r8	; Already initialized?
30	beq	dram_init_finished
31	nop
32
33#include "../../arch-v10/lib/dram_init.S"
34
35dram_init_finished:
36
37	;; Initiate the PA and PB ports
38
39	move.b   CONFIG_ETRAX_DEF_R_PORT_PA_DATA, $r0
40	move.b   $r0, [R_PORT_PA_DATA]
41
42	move.b   CONFIG_ETRAX_DEF_R_PORT_PA_DIR, $r0
43	move.b   $r0, [R_PORT_PA_DIR]
44
45	move.b   CONFIG_ETRAX_DEF_R_PORT_PB_DATA, $r0
46	move.b   $r0, [R_PORT_PB_DATA]
47
48	move.b   CONFIG_ETRAX_DEF_R_PORT_PB_DIR, $r0
49	move.b   $r0, [R_PORT_PB_DIR]
50
51	;; Setup the stack to a suitably high address.
52	;; We assume 8 MB is the minimum DRAM in an eLinux
53	;; product and put the sp at the top for now.
54
55	move.d	0x40800000, $sp
56
57	;; Figure out where the compressed piggyback image is
58	;; in the flash (since we wont try to copy it to DRAM
59	;; before unpacking). It is at _edata, but in flash.
60	;; Use (_edata - basse) as offset to the current PC.
61
62basse:	move.d	$pc, $r5
63	and.d	0x7fffffff, $r5	; strip any non-cache bit
64	subq	2, $r5		; compensate for the move.d $pc instr
65	move.d	$r5, $r0		; save for later - flash address of 'basse'
66	add.d	_edata, $r5
67	sub.d	basse, $r5	; $r5 = flash address of '_edata'
68
69	;; Copy text+data to DRAM
70
71	move.d	basse, $r1	; destination
72	move.d	_edata, $r2	; end destination
731:	move.w	[$r0+], $r3
74	move.w	$r3, [$r1+]
75	cmp.d	$r2, $r1
76	bcs	1b
77	nop
78
79	move.d	$r5, [input_data] ; for the decompressor
80
81
82	;; Clear the decompressors BSS (between _edata and _end)
83
84	moveq	0, $r0
85	move.d	_edata, $r1
86	move.d	_end, $r2
871:	move.w	$r0, [$r1+]
88	cmp.d	$r2, $r1
89	bcs	1b
90	nop
91
92	;;  Save command line magic and address.
93	move.d	_cmd_line_magic, $r12
94	move.d  $r10, [$r12]
95	move.d	_cmd_line_addr, $r12
96	move.d  $r11, [$r12]
97
98	;; Do the decompression and save compressed size in inptr
99
100	jsr	decompress_kernel
101
102	;; Put start address of root partition in $r9 so the kernel can use it
103	;; when mounting from flash
104
105	move.d	[input_data], $r9	; flash address of compressed kernel
106	add.d	[inptr], $r9		; size of compressed kernel
107
108	;; Restore command line magic and address.
109	move.d  _cmd_line_magic, $r10
110	move.d  [$r10], $r10
111	move.d  _cmd_line_addr, $r11
112	move.d  [$r11], $r11
113
114	;; Enter the decompressed kernel
115	move.d	RAM_INIT_MAGIC, $r8	; Tell kernel that DRAM is initialized
116	jump	0x40004000	; kernel is linked to this address
117
118	.data
119
120input_data:
121	.dword	0		; used by the decompressor
122_cmd_line_magic:
123	.dword 0
124_cmd_line_addr:
125	.dword 0
126#include "../../arch-v10/lib/hw_settings.S"
127