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kernel/linux-imx6_3.14.28/firmware/av7110/Boot.S 2.75 KB
6b13f685e   김민수   BSP 최초 추가
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  /*
     Boot.S: boot loader for Siemens DVB-S card
  
     Copyright (C) 2001 Convergence integrated media GmbH
  	              Written by Ralph Metzler
  		                 <rjkm@convergence.de>
     Copyright (C) 2006 Matthieu CASTET <castet.mattheiu@free.fr>
  
     This program is free software; you can redistribute it and/or
     modify it under the terms of the GNU General Public License
     as published by the Free Software Foundation; either version 2
     of the License, or (at your option) any later version.
  
     This program is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     GNU General Public License for more details.
  
     You should have received a copy of the GNU General Public License
     along with this program; if not, write to the Free Software
     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA.
  
  */
  
  /*
  	check AV711x_3_1.pdf for some hardware infos
  	build it with :
  	$ cc -mbig-endian -c Boot.S
  	$ ld -Ttext 0x2c000000 -EB -o Boot Boot.o
  	$ objcopy -Obinary Boot
  */
  
  	.text
  	.align
  	.globl _start
  _start:
  	b reset			// reset vector
  	movs  pc, r14           // undefined
  	subs  pc, r14, #4       // SWI
  	subs  pc, r14, #4       // prefetch abort
  	subs  pc, r14, #8       // data abort
  	subs  pc, r14, #4       // reserved
  	subs  pc, r14, #4       // IRQ
  	subs  pc, r14, #4       // FIQ
  
  	.word tbl               // table needed by firmware ROM
  tbl:	.word (endtbl - tbl)
  	.word 0
    	.word conf
  endtbl:	.word 0
  conf:	.word 0xa5a55a5a
  	.word 0x001f1555
  	.word 0x00000009
  
  reset:	ldr	r13, buffer
  	ldr	r4, flag
  	mov	r0, #0
  	str	r0, [r4]
  	str	r0, [r4, #4]
  
  	ldr		r1, wait_address
  	ldr		r2, flag_address
  	ldr		r3, sram
  
  copycode: // copy the code HW Sram
  	ldmia	r1!, {r5-r12}
  	stmia	r3!, {r5-r12}
  	cmp		r1, r2
  	ble 	copycode
  	ldr		pc, sram // jump to the copied code
  
  wait:	ldrh	r1, [r4]        // wait for flag!=0
   	cmp	r1, #0
  	beq	wait
  
  	mov	r1, r13         // buffer address
   	ldr	r3, [r4,#4]     // destaddr
  
   	ldrh	r2, [r4,#2]     // get segment length
  	add     r2, r2, #63     // round length to next 64 bytes
  	movs	r2, r2, lsr #6  // and divide by 64
  	moveq	r0, #2          // if 0, set flag to 2, else signal
  	strh	r0, [r4]        // that buffer is accepted by setting to 0
          beq wait
  	
  copyloop:
  	ldmia	r1!, {r5-r12}
  	stmia	r3!, {r5-r12}
  	ldmia	r1!, {r5-r12}
  	stmia	r3!, {r5-r12}
   	subs	r2, r2, #1
   	bne	copyloop
  
  	eor     r13, r13, #0x1400    // switch to other buffer
  	b	wait
  
  // flag is stored at 0x2c0003f8, length at 0x2c0003fa,
  // destaddr at 0x2c0003fc
  
  flag:	.word	0x2c0003f8
  
  
  // buffer 1 is at 0x2c000400, buffer 2 at 0x2c001000
  
  buffer:	.word	0x2c000400
  
  sram: .word   0x9e000800
  wait_address: .word   wait
  flag_address: .word   flag