1/*
2   Boot.S: boot loader for Siemens DVB-S card
3
4   Copyright (C) 2001 Convergence integrated media GmbH
5	              Written by Ralph Metzler
6		                 <rjkm@convergence.de>
7   Copyright (C) 2006 Matthieu CASTET <castet.mattheiu@free.fr>
8
9   This program is free software; you can redistribute it and/or
10   modify it under the terms of the GNU General Public License
11   as published by the Free Software Foundation; either version 2
12   of the License, or (at your option) any later version.
13
14   This program is distributed in the hope that it will be useful,
15   but WITHOUT ANY WARRANTY; without even the implied warranty of
16   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17   GNU General Public License for more details.
18
19   You should have received a copy of the GNU General Public License
20   along with this program; if not, write to the Free Software
21   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA.
22
23*/
24
25/*
26	check AV711x_3_1.pdf for some hardware infos
27	build it with :
28	$ cc -mbig-endian -c Boot.S
29	$ ld -Ttext 0x2c000000 -EB -o Boot Boot.o
30	$ objcopy -Obinary Boot
31*/
32
33	.text
34	.align
35	.globl _start
36_start:
37	b reset			// reset vector
38	movs  pc, r14           // undefined
39	subs  pc, r14, #4       // SWI
40	subs  pc, r14, #4       // prefetch abort
41	subs  pc, r14, #8       // data abort
42	subs  pc, r14, #4       // reserved
43	subs  pc, r14, #4       // IRQ
44	subs  pc, r14, #4       // FIQ
45
46	.word tbl               // table needed by firmware ROM
47tbl:	.word (endtbl - tbl)
48	.word 0
49  	.word conf
50endtbl:	.word 0
51conf:	.word 0xa5a55a5a
52	.word 0x001f1555
53	.word 0x00000009
54
55reset:	ldr	r13, buffer
56	ldr	r4, flag
57	mov	r0, #0
58	str	r0, [r4]
59	str	r0, [r4, #4]
60
61	ldr		r1, wait_address
62	ldr		r2, flag_address
63	ldr		r3, sram
64
65copycode: // copy the code HW Sram
66	ldmia	r1!, {r5-r12}
67	stmia	r3!, {r5-r12}
68	cmp		r1, r2
69	ble 	copycode
70	ldr		pc, sram // jump to the copied code
71
72wait:	ldrh	r1, [r4]        // wait for flag!=0
73 	cmp	r1, #0
74	beq	wait
75
76	mov	r1, r13         // buffer address
77 	ldr	r3, [r4,#4]     // destaddr
78
79 	ldrh	r2, [r4,#2]     // get segment length
80	add     r2, r2, #63     // round length to next 64 bytes
81	movs	r2, r2, lsr #6  // and divide by 64
82	moveq	r0, #2          // if 0, set flag to 2, else signal
83	strh	r0, [r4]        // that buffer is accepted by setting to 0
84        beq wait
85
86copyloop:
87	ldmia	r1!, {r5-r12}
88	stmia	r3!, {r5-r12}
89	ldmia	r1!, {r5-r12}
90	stmia	r3!, {r5-r12}
91 	subs	r2, r2, #1
92 	bne	copyloop
93
94	eor     r13, r13, #0x1400    // switch to other buffer
95	b	wait
96
97// flag is stored at 0x2c0003f8, length at 0x2c0003fa,
98// destaddr at 0x2c0003fc
99
100flag:	.word	0x2c0003f8
101
102
103// buffer 1 is at 0x2c000400, buffer 2 at 0x2c001000
104
105buffer:	.word	0x2c000400
106
107sram: .word   0x9e000800
108wait_address: .word   wait
109flag_address: .word   flag
110