Uboot work sequence< colibri_pxa270 >
Uboot work sequence< colibri_pxa270 >
1. Start.s <\arch\arm\cpu\pxa>
_start: b reset -->
reset: -->
bl _main -->
2. Crt0.s<\arch\arm\lib>
ENTRY(_main) -->
bl board_init_f -->
board_init_f() à < Board_f.c > run all the function in init_sequence_f
ldr pc, =board_init_r /* this is auto-relocated! */
3. Board_r.c<\common>
board_init_r --> run all the function in init_sequence_r
run_main_loop -->
main_loop() -->
4. Main.c<\common>
process_boot_delay --> run_command_list
parse_file_outer -->
parse_file_outer解析用户命令
对于uboot支持的每一个命令，是通过U_BOOT_CMD宏定义的
http://wenku.baidu.com/view/9ba118f7c8d376eeaeaa319a.html
#define CONFIG_BOOTCOMMAND \
"if mmc init && fatload mmc 0 0xa0000000 uImage; then " \
"bootm 0xa0000000; " \
"fi; " \
"if usb reset && fatload usb 0 0xa0000000 uImage; then " \
"bootm 0xa0000000; " \
"fi; " \
"bootm 0x80000;"
5. Cmd_bootm.c <\common>
U_BOOT_CMD(
bootm, CONFIG_SYS_MAXARGS, 1, do_bootm,
"boot application image from memory", bootm_help_text);
do_bootm -->
do_bootm_states --> boot_fn = boot_os[images->os.os];设置函数为下面的进入做准备
bootm_find_os ->
1) boot_get_kernel -> memmove(&images->legacy_hdr_os_copy, hdr,sizeof(image_header_t));
2) /* find kernel entry point */
if (images.legacy_hdr_valid) {
images.ep = image_get_ep(&images.legacy_hdr_os_copy);
boot_selected_os -->
boot_fn(state, argc, argv, images); --> do_bootm_linux -->
boot_jump_linux --> kernel_entry = (void (*)(int, int, uint))images->ep;
kernel_entry -->
Configure board: Colibri_pxa270.h (include\configs)