Uboot for PXA (1)

UBOOT is a loader based on PPC boot loader.

The file structure is simply shown as below:

u-boot-arm
|_board
|_common
|_cpu
|_disk
|_doc
|_drivers
|_examples
|_fs
|_include
|_lib_arm
|_lib_avr32
|_lib_blackfin
|_lib_generic
|_lib_i386
|_lib_m68k
|_lib_microblaze
|_lib_mips
|_lib_nios
|_lib_nios2
|_lib_ppc
|_lib_sh
|_lib_sparc
|_libfdt
|_nand_spl
|_net
|_nenand_ipl
|_post
|_tools
...
...
...

board: All supporting target boards ard defined in this directory. For example \u-boot-arm\board\pxa\aspenite
A board_init function is defined in aspenite_168.c

cpu: All supoorting CPU type are defined in this directory. For example \u-boot-arm\cpu\pxa
All CPU env init including interrupts are defined. start.s is the first pieces of codes running
in the system. Its main task is to copy the whole uboot from flash into ram & start execution.

common: This is the directory stored all the uboot commands. We normally look at cmb_boot.c & cmd_bootm.c
It has the function to verify the kernel & doing decompression.)

drivers: This directory provides all the interface drivers.

fs: This directory provides all the supporting file system.

lib_arm: This directory providing all the common libraries for arm platform.

include: All headers are placed in this directory. For example u-boot-arm\include\asm-arm\arch-pxa & u-boot-arm\include\asm-arm\arch-pxa168