??????Boot Loader??

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??????Boot Loader??

• ???
• ?????????
• 2009?5?

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????

• 1. Boot Loader???????
• 2. Boot Loader???????
• 3. Boot Loader??
• ??? Boot Loader????
• ??? U-BOOT??????

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1. Boot Loader???????

• Boot Loader?????????????????????
• ??????????????????
• ??????????????????,?????????????????????
• ???Boot Loader?????????0x00000000 ?

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• Boot Loader????????
• ?????CPU?????????Boot Loader
• Boot Loader?????
• Boot Loader????????
• ??????????????????
• Boot Loader?????

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• Boot Loader?????
• ??????
• ????
• Boot Loader?????????????

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2. Boot Loader???????

• ????????,Boot Loader????????????????
• ???Boot Loader?????1???2????
• ??1?????CPU???????
• ??2?????????

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2.1 Boot Loader??1??

• Boot Loader ???1????????
• 1)????????
• ???????
• ??CPU????????
• RAM???
• ???LED
• ??CPU????/??Cache

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• 2)?????2??RAM??
• ????2?????????,?????????????
• ?????????????????????RAM??

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• 3)????2?RAM?
• 4)??????sp
• 5)?????2?C???
• Boot Loader ? ??2 ?????????? RAM ??????????,???

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(No Transcript)
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2.2 Boot Loader??2??

• 1)???????????????
• ?????????,?????????I/O????
• ???????

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• 2)?????????
• ???????
• ????????????RAM???????????????
• ???????

typedef struct memory_area_struct u32 start / ??????? / u32 size / ??????? / int used memory_area_t
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• 3)??????????????
• ?????????
• ????????????
• MEM_START 0X8000
• ?????????????
• MEM_START 0X00100000
• ?Flash???
• While??

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• 4)?????????
• ????(tagged list)??????????,???????????ATAG_CORE??
  ,???ATAG_NONE??
• ???Linux???,?????Boot Loader??????????ATAG_CORE?A
  TAG_MEM?ATAG_CMDLINE?ATAG_RAMDISK?ATAG_INITRD

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• ???ATAG_CORE?????

params (struct tag )BOOT_PARAMS params-gthdr.tag ATAG_CORE params-gthdr.size tag_size(tag_core) params-gtu.core.flags 0 params-gtu.core.pagesize 0 params-gtu.core.rootdev 0 params tag_next(params)
BOOT_PARAMS ??????????????????,??params???struct
tag???????tag_next()??????????????,???????????????
???
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• 5)????
• CPU??????
• R00
• R1????ID???????,????
• linux/arch/arm/tools/mach-types?
• R2?????????RAM??????
• CPU ??
• ??????(IRQs?FIQs)
• CPU??SVC??
• Cache?MMU???
• MMU????
• ??Cache?????????
• ??Cache????

HOW TO CALL ?
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2.3 ??????

• ??????????????????????????
• ??????????????????????,?????
• Boot Loader ????????????
• ???host ?????????????????

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• Boot Loader ???????????????????
• ?????????????????????,?????????????
• Boot Loader ?????????????????????????
• ???? Boot Loader ?????????????????????????????

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3. Boot Loader??

• ??? Boot Loader????
• ??? U-BOOT??????

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??? Boot Loader????(1)

• ??XsBase255?BootLoader
• ????XsBase255???JTAG?? Jflash-XSBase255
• ????XSBase?Boot Loader x-boot255
• ????
• ??JTAG??BootLoader

root_at_XSBase JTAG ./Jflash-XSBase255 x-boot255
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??? Boot Loader????(2)

• ???? Bootloader ??,???????????????
  description????

Usage Help
Description ????????????
Arguments None
Example X-HYPER255gt Help
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Usage Reload kernel/ramdisk
Description ?Flash????image???SDRAM ???? kernel image? SDRAM, Autoboot?????
Arguments Kernel ?flash? kernel image??? SDRAM 0xa0008000 Ramdisk ?flash? ramdisk??? SDRAM 0xa0800000
Example X-HYPER255gt reload kernel
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Usage Tftp file loader/kernel/root/ramdisk Tftp file addr
Description ??Ethernet? Host????????SDRAM?
Arguments Loader??????????loader?SDRAM 0xa0000000 Kernel??????????kernel? SDRAM 0xa0008000 Root ?????????? 0xa0000000 Ramdisk ?????????? 0xA0800000? Addr SDRAM????????????
Example X-HYPER255gt tftp zImage kernel X-HYPER255gt tftp zImage 0xa0000000
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Usage Flash loader/kernel/root/ramdisk Flash dest src len
Description ?SDRAM???????flash?????
Arguments Loader-?SDRAM?loader 0xa00000000???flash?0x0?? Kernel-?SDRAM?Kernel 0xa00080000???flash?0xc0000 ?? Root-?SDRAM?root 0xa0000000???flash?0x1c0000?? Ramdisk-?SDRAM?ramdisk 0xA0800000???Flash?0x1c00 00?? Dest-???flash???? Src-????????? Len-?????
Example XSBASE255gt flash kernel XSBASE255gt flash 0xc0000 0xa0000000 0x100000
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Usage Boot Boot opt1 opt2 Boot addr opt1 opt2
Description ??SDRAM?? kernel ???? arguments ?? ?????????kernel?
Arguments Opt1 kernel option(Only 0) Opt2 machine type( X-Hyer255 200) Addr kernel image address
Example XSBASE255gt boot XSBASE255gt boot 0 200 XSBASE255gt boot 0xa0008000 0 200
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??? U-BOOT??????(1)

• U-BOOT???
• ????Flash?DOC?IDE?IIC?EEROM?RTC
  ??????BOOT-LOADER???IDE?DOC??????
• ?????kermit?S-record????
• ??????ELF32?uImage???Image,?Linux????????
• ?????????

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• ??????(??BASH??)
• ??WatchDog?LCD logo???????
• ??MTD?????
• ????
• ???????

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??? U-BOOT??????(2)

• U-BOOT?????
• /board?????????????
• /common??????????,???????C??
• /cpuCPU????
• /diskdisk?????????
• /doc??
• /drivers????????,?????USB?

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• /fs?????????
• /net????????
• /lib_arm?ARM?????????
• /tools??S-Record???? ?U-BOOT images???

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??? U-BOOT??????(3)

• ?U-BOOT???
• ???????????????
• ?include/configs????????xsbase.h
• ?board/?????xsbase??,??????flash.c?memsetup.S?xsb
  ase.c?Makefile?u-boot.lds
• ??????????,cs8900?????????cs8900.c ?cs8900.h

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??? U-BOOT??????(4)

• ??Makefile
• ?u-boot-1.1.2/Makefile???
• xsbase_config unconfig
• _at_./mkconfig (_at__config) arm pxa xsbase

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??? U-BOOT??????(5)

• ??????
• ???make clean
• ????make xsbase_config
• ???make all
• ??????
• u-bootELF?????,??????Debug?????
• u-boot.bin???bin??,??????????????????
• u-boot.srecMotorola S-Record??,??????????????

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??? U-BOOT??????(6)

• ??JTAG??u-boot.bin???Flash????,?????u-boot
• ??help????????