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ARM·存儲器配置

作者： 時間：2016-11-24 來源：網(wǎng)絡(luò) 收藏
關(guān)于配置SDRAM的這個程序，因?yàn)檠芯苛?天，所以這里最后再復(fù)習(xí)一下
首先補(bǔ)充一下基本的知識：
運(yùn)行地址->鏈接地址
在SRAM或者SDRAM中執(zhí)行程序時，PC指向這個地址，那么命令就應(yīng)該在這個地址里面 ；
加載地址->存儲地址
程序保存在NAND FLSAH中的地址
位置無關(guān)碼：B，BL，MOV
位置有關(guān)碼：LDR PC，=Label
【關(guān)于Makefile】
sdram.bin : head.S leds.c
arm-linux-gcc -c -o head.o head.S
arm-linux-gcc -c -o leds.o leds.c
arm-linux-ld -Ttext 0x30000000 head.o leds.o -o sdram_elf
arm-linux-objcopy -O binary -S sdram_elf sdram.bin
arm-linux-objdump -D -m arm sdram_elf > sdram.dis
clean: rm -f sdram.dis sdram.bin sdram_elf *.o
這里我們看到這一句“arm-linux-ld -Ttext 0x30000000 head.o leds.o -o sdram_elf ”，說明該程序是放在0x3000 0000的地址中的，由mini2440存儲地址可知，那里是SDRAM的首地址
【head.S】（配置SDRAM）
@*************************************************************************
@ File：head.S
@ 功能：設(shè)置SDRAM，將程序復(fù)制到SDRAM，然后跳到SDRAM繼續(xù)執(zhí)行
@*************************************************************************
.equ MEM_CTL_BASE, 0x48000000
.equ SDRAM_BASE, 0x30000000
.text
.global _start
_start:
bl disable_watch_dog @ 關(guān)閉WATCHDOG，否則CPU會不斷重啟
bl memsetup @ 設(shè)置存儲控制器
bl copy_steppingstone_to_sdram @ 復(fù)制代碼到SDRAM中
ldr pc, =on_sdram @ 跳到SDRAM中繼續(xù)執(zhí)行
on_sdram:
ldr sp, =0x34000000 @ 設(shè)置堆棧
bl main
halt_loop:
b halt_loop
disable_watch_dog:
@ 往WATCHDOG寄存器寫0即可
mov r1, #0x53000000
mov r2, #0x0
str r2, [r1]
mov pc, lr @ 返回
copy_steppingstone_to_sdram:
@ 將Steppingstone的4K數(shù)據(jù)全部復(fù)制到SDRAM中去
@ Steppingstone起始地址為0x00000000，SDRAM中起始地址為0x30000000
mov r1, #0
ldr r2, =SDRAM_BASE
mov r3, #4*1024
1:
ldr r4, [r1],#4 @ 從Steppingstone讀取4字節(jié)的數(shù)據(jù)，并讓源地址加4
str r4, [r2],#4 @ 將此4字節(jié)的數(shù)據(jù)復(fù)制到SDRAM中，并讓目地地址加4
cmp r1, r3 @ 判斷是否完成：源地址等于Steppingstone的未地址？
bne 1b @ 若沒有復(fù)制完，繼續(xù)
mov pc, lr @ 返回
memsetup:
@ 設(shè)置存儲控制器以便使用SDRAM等外設(shè)
mov r1, #MEM_CTL_BASE @ 存儲控制器的13個寄存器的開始地址
adrl r2, mem_cfg_val @ 這13個值的起始存儲地址
add r3, r1, #52 @ 13*4 = 54
1:
ldr r4, [r2], #4 @ 讀取設(shè)置值，并讓r2加4
str r4, [r1], #4 @ 將此值寫入寄存器，并讓r1加4
cmp r1, r3 @ 判斷是否設(shè)置完所有13個寄存器
bne 1b @ 若沒有寫成，繼續(xù)
mov pc, lr @ 返回
.align 4
mem_cfg_val:
@ 存儲控制器13個寄存器的設(shè)置值
.long 0x22011110 @ BWSCON
.long 0x00000700 @ BANKCON0
.long 0x00000700 @ BANKCON1
.long 0x00000700 @ BANKCON2
.long 0x00000700 @ BANKCON3
.long 0x00000700 @ BANKCON4
.long 0x00000700 @ BANKCON5
.long 0x00018005 @ BANKCON6
.long 0x00018005 @ BANKCON7
.long 0x008C07A3 @ REFRESH
.long 0x000000B1 @ BANKSIZE
.long 0x00000030 @ MRSRB6
.long 0x00000030 @ MRSRB7
【反匯編】
sdram_elf: file format elf32-littlearm
Disassembly of section .text:
30000000 <_start>:
30000000: eb000005 bl 3000001c
30000004: eb000010 bl 3000004c
30000008: eb000007 bl 3000002c
3000000c: e59ff090 ldr pc, [pc, #144] ; 300000a4
30000010 :
30000010: e3a0d30d mov sp, #872415232 ; 0x34000000
30000014: eb000035 bl 300000f0
30000018 :
30000018: eafffffe b 30000018
3000001c :
3000001c: e3a01453 mov r1, #1392508928 ; 0x53000000
30000020: e3a02000 mov r2, #0 ; 0x0
30000024: e5812000 str r2, [r1]
30000028: e1a0f00e mov pc, lr
3000002c :
3000002c: e3a01000 mov r1, #0 ; 0x0
30000030: e3a02203 mov r2, #805306368 ; 0x30000000
30000034: e3a03a01 mov r3, #4096 ; 0x1000
30000038: e4914004 ldr r4, [r1], #4
3000003c: e4824004 str r4, [r2], #4
30000040: e1510003 cmp r1, r3
30000044: 1afffffb bne 30000038
30000048: e1a0f00e mov pc, lr
3000004c :
3000004c: e3a01312 mov r1, #1207959552 ; 0x48000000
30000050: e28f2018 add r2, pc, #24 ; 0x18
30000054: e1a00000 nop (mov r0,r0)
30000058: e2813034 add r3, r1, #52 ; 0x34
3000005c: e4924004 ldr r4, [r2], #4
30000060: e4814004 str r4, [r1], #4
30000064: e1510003 cmp r1, r3
30000068: 1afffffb bne 3000005c
3000006c: e1a0f00e mov pc, lr
30000070 :
30000070: 22011110 .word 0x22011110
30000074: 00000700 .word 0x00000700
30000078: 00000700 .word 0x00000700
3000007c: 00000700 .word 0x00000700
30000080: 00000700 .word 0x00000700
30000084: 00000700 .word 0x00000700
30000088: 00000700 .word 0x00000700
3000008c: 00018005 .word 0x00018005
30000090: 00018005 .word 0x00018005
30000094: 008c07a3 .word 0x008c07a3
30000098: 000000b1 .word 0x000000b1
3000009c: 00000030 .word 0x00000030
300000a0: 00000030 .word 0x00000030
300000a4: 30000010 .word 0x30000010
300000a8: e1a00000 .word 0xe1a00000
300000ac: e1a00000 .word 0xe1a00000
300000b0 :
300000b0: e52db004 push {fp} ; (str fp, [sp, #-4]!)
300000b4: e28db000 add fp, sp, #0 ; 0x0
300000b8: e24dd00c sub sp, sp, #12 ; 0xc
300000bc: e50b0008 str r0, [fp, #-8]
300000c0: e51b2008 ldr r2, [fp, #-8]
300000c4: e3520000 cmp r2, #0 ; 0x0
300000c8: 03a03000 moveq r3, #0 ; 0x0
300000cc: 13a03001 movne r3, #1 ; 0x1
300000d0: e20310ff and r1, r3, #255 ; 0xff
300000d4: e2423001 sub r3, r2, #1 ; 0x1
300000d8: e50b3008 str r3, [fp, #-8]
300000dc: e3510000 cmp r1, #0 ; 0x0
300000e0: 1afffff6 bne 300000c0
300000e4: e28bd000 add sp, fp, #0 ; 0x0
300000e8: e8bd0800 pop {fp}
300000ec: e12fff1e bx lr
300000f0 :
300000f0: e92d4800 push {fp, lr}
300000f4: e28db004 add fp, sp, #4 ; 0x4
300000f8: e3a02456 mov r2, #1442840576 ; 0x56000000
300000fc: e2822010 add r2, r2, #16 ; 0x10
30000100: e3a03456 mov r3, #1442840576 ; 0x56000000
30000104: e2833010 add r3, r3, #16 ; 0x10
30000108: e5933000 ldr r3, [r3]
3000010c: e3c33bff bic r3, r3, #261120 ; 0x3fc00
30000110: e5823000 str r3, [r2]
30000114: e3a02456 mov r2, #1442840576 ; 0x56000000
30000118: e2822010 add r2, r2, #16 ; 0x10
3000011c: e3a03456 mov r3, #1442840576 ; 0x56000000
30000120: e2833010 add r3, r3, #16 ; 0x10
30000124: e5933000 ldr r3, [r3]
30000128: e3833b55 orr r3, r3, #87040 ; 0x15400
3000012c: e5823000 str r3, [r2]
30000130: e3a02456 mov r2, #1442840576 ; 0x56000000
30000134: e2822014 add r2, r2, #20 ; 0x14
30000138: e3a03456 mov r3, #1442840576 ; 0x56000000
3000013c: e2833014 add r3, r3, #20 ; 0x14
30000140: e5933000 ldr r3, [r3]
30000144: e3833e1e orr r3, r3, #480 ; 0x1e0
30000148: e5823000 str r3, [r2]
3000014c: e3a02456 mov r2, #1442840576 ; 0x56000000
30000150: e2822014 add r2, r2, #20 ; 0x14
30000154: e3a03456 mov r3, #1442840576 ; 0x56000000
30000158: e2833014 add r3, r3, #20 ; 0x14
3000015c: e5933000 ldr r3, [r3]
30000160: e3c33020 bic r3, r3, #32 ; 0x20
30000164: e5823000 str r3, [r2]
30000168: e3a00064 mov r0, #100 ; 0x64
3000016c: ebffffcf bl 300000b0
30000170: eafffff5 b 3000014c
Disassembly of section .comment:
00000000 <.comment>:
0: 43434700 movtmi r4, #14080 ; 0x3700
4: 5328203a teqpl r8, #58 ; 0x3a
8: 6372756f cmnvs r2, #465567744 ; 0x1bc00000
c: 20797265 rsbscs r7, r9, r5, ror #4
10: 202b2b47 eorcs r2, fp, r7, asr #22
14: 6574694c ldrbvs r6, [r4, #-2380]!
18: 30303220 eorscc r3, r0, r0, lsr #4
1c: 2d337138 ldfcss f7, [r3, #-224]!
20: 20293237 eorcs r3, r9, r7, lsr r2
24: 2e332e34 mrccs 14, 1, r2, cr3, cr4, {1}
28: Address 0x00000028 is out of bounds.
Disassembly of section .ARM.attributes:
00000000 <.ARM.attributes>:
0: 00002541 andeq r2, r0, r1, asr #10
4: 61656100 cmnvs r5, r0, lsl #2
8: 01006962 tsteq r0, r2, ror #18
c: 0000001b andeq r0, r0, fp, lsl r0
10: 00543405 subseq r3, r4, r5, lsl #8
14: 01080206 tsteq r8, r6, lsl #4
18: 01140412 tsteq r4, r2, lsl r4
1c: 03170115 tsteq r7, #1073741829 ; 0x40000005
20: 01190118 tsteq r9, r8, lsl r1
24: Address 0x00000024 is out of bounds.
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