1. 汇编编程
为什么要学习汇编
1). Bootloader初始化
2). Linux kernel
3). 高效
2. ARM汇编分类
1. ARM标准汇编：ARM公司得汇编器适合在Windows平台下使用
2. GNU汇编：适用于GNU交叉编译工具链中的汇编器，适合Linux开发平台
3. 汇编程序框架
.section .data
<初始化的数据>
.setction .bss
<未初始化的数据>
.setction .text
.gobal _start
_start
<汇编代码>
程序入口在_start
.text
.gobal _start
__start:
建立汇编程序环境
[root@cfm880 ~]# cd /home/S3-ARM/
[root@cfm880 S3-ARM]# makdir Part3
-bash: makdir: command not found
[root@cfm880 S3-ARM]# mkdir Part3
[root@cfm880 S3-ARM]# cd Part3
[root@cfm880 Part3]# mkdir lesson1
[root@cfm880 Part3]# chmod 777 ./
[root@cfm880 Part3]# cd lesson1/
[root@cfm880 lesson1]# chmod 777 ./
[root@cfm880 lesson1]# ls
[root@cfm880 lesson1]# vim start.S
.text
.global _start
_start:
mov r1, #1
mov r2, #2
mov r3, #3
[root@cfm880 lesson1]# vim Makefile
all:start.o
arm-linux-ld -Ttext 0x50008000 -o start.elf $^
%.o:%.S
arm-linux-gcc -g -o $@ $^ -c
clean:
rm *.o *.elft
链接地址为什么是0x50008000而不是0x50000000
双击
# tiny6410_config
# connect to the J-Link gdb server
target remote localhost:2331
# Set JTAG speed to 30 kHz
monitor endian little
monitor speed 30
# Reset the target
monitor reset
monitor sleep 10
#
# CPU core initialization (to be done by user)
#
# Set the processor mode
monitor reg cpsr = 0xd3
#config MMU
#flush v3/v4 cache
monitor cp15 7, 7, 0, 0 = 0x0
#/* flush v4 TLB */
monitor cp15 8, 7, 0, 0 = 0x0
#disable MMU stuff and caches
monitor cp15 1, 0, 0, 0 =0x1002
#Peri port setup
monitor cp15 15, 2, 0, 4 = 0x70000013
#disable watchdog
monitor MemU32 0x7e004000 = 0x00000000
monitor sleep 10
#disable interrupt
monitor MemU32 0x71200014 = 0x00000000
monitor MemU32 0x71300014 = 0x00000000
monitor MemU32 0x7120000C = 0x00000000
monitor MemU32 0x7130000C = 0x00000000
monitor MemU32 0x71200F00 = 0x00000000
monitor MemU32 0x71300F00 = 0x00000000
#set clock
monitor MemU32 0x7e00f900 = 0x0000801e
monitor MemU32 0x7e00f000 = 0x0000ffff
monitor MemU32 0x7e00f004 = 0x0000ffff
monitor MemU32 0x7e00f020 = 0x01043310
monitor MemU32 0x7e00f00C = 0xc2150601
monitor MemU32 0x7e00f010 = 0xc2150601
monitor MemU32 0x7e00f024 = 0x00000003
monitor MemU32 0x7e00f014 = 0x00200102
monitor MemU32 0x7e00f018 = 0x00000000
monitor MemU32 0x7e00f01C = 0x14000007
#config sdram
monitor MemU32 0x7e00f120 = 0x00000008
monitor MemU32 0x7e001004 = 0x00000004
monitor MemU32 0x7e001010 = 0x0000040f
monitor MemU32 0x7e001014 = 0x00000006
monitor MemU32 0x7e001018 = 0x00000001
monitor MemU32 0x7e00101c = 0x00000002
monitor MemU32 0x7e001020 = 0x00000006
monitor MemU32 0x7e001024 = 0x0000000a
monitor MemU32 0x7e001028 = 0x0000000c
monitor MemU32 0x7e00102c = 0x0000018f
monitor MemU32 0x7e001030 = 0x0000000c
monitor MemU32 0x7e001034 = 0x00000002
monitor MemU32 0x7e001038 = 0x00000002
monitor MemU32 0x7e00103c = 0x00000002
monitor MemU32 0x7e001040 = 0x00000002
monitor MemU32 0x7e001044 = 0x00000013
monitor MemU32 0x7e001048 = 0x00000013
monitor MemU32 0x7e00100C = 0x00010012
monitor MemU32 0x7e00104C = 0x00000b45
monitor MemU32 0x7e001200 = 0x000150f8
monitor MemU32 0x7e001304 = 0x00000000
monitor MemU32 0x7e001008 = 0x000c0000
monitor MemU32 0x7e001008 = 0x00000000
monitor MemU32 0x7e001008 = 0x00040000
monitor MemU32 0x7e001008 = 0x00040000
monitor MemU32 0x7e001008 = 0x000a0000
monitor MemU32 0x7e001008 = 0x00080032
monitor MemU32 0x7e001004 = 0x00000000
# Setup GDB for faster downloads
#set remote memory-write-packet-size 1024
set remote memory-write-packet-size 4096
set remote memory-write-packet-size fixed
monitor speed 12000
break _start
load
点击Debug