U-boot 2014 启动流程详细分析

来源：互联网发布：中国国民收入数据库编辑：程序博客网时间：2024/04/30 12:36

U-boot 2014 启动流程：

-> _start: b reset (arch/arm/cpu/armv7/start.S line 28)

-> bl _main (line 151)

->ENTRY(_main) (arch/arm/lib/crt0.S line 58)

-> bl board_init_f (line 74)

->void __weak board_init_f(ulong dummy) (arch/arm/lib/spl.c line 26)

->board_init_r(NULL, 0); (line 34)

->void board_init_r(gd_t *id, ulong dest_addr) (arch/arm/lib/board.c line 513)

->board_init(); (line 529)

->mem_malloc_init (malloc_start, TOTAL_MALLOC_LEN); (line 552)

->flash_init(); (line 562)

->nand_init(); (line 588)

->mmc_initialize(gd->bd); (line 597)

->env_relocate(); (line 607)

->console_init_r(); (line 624)

->interrupt_init(); (line 645)

->enable_interrupts(); (line 647)

->eth_initialize(gd->bd); (line 661)

->main_loop(); (line 697)

->void main_loop(void) (common/main.c line 416)

->process_boot_delay(); (line 475) //串口监听实现

->static void process_boot_delay(void) (common/main.c line 322)

->s = getenv ("bootdelay"); (line 342)

->bootdelay = s ? (int)simple_strtol(s, NULL, 10) : CONFIG_BOOTDELAY; (line 343)

->if (bootdelay != -1 && s && !abortboot(bootdelay)) (line 394)

->run_command_list(s, -1, 0); (line 399) //启动内核的入口函数 s = getenv ("bootcmd");

->查找bootcmd环境变量指定命令->最终执行bootm命令

->bootm, CONFIG_SYS_MAXARGS, 1, do_bootm, (common/cmd_bootm.c line 1054 ~ line 1057)

->int do_bootm(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) (common/cmd_bootm.c line 777)

->return do_bootm_states(cmdtp, flag, argc, argv, BOOTM_STATE_START | (line 816)

->static int do_bootm_states(cmd_tbl_t *cmdtp, int flag, int argc, (common/cmd_bootm.c line 619)

->boot_fn = boot_os[images->os.os]; (line 687)

->static boot_os_fn *boot_os[] = { (common/cmd_bootm.c line 144)

->[IH_OS_LINUX] = do_bootm_linux, (line 147)

->int do_bootm_linux(int flag, int argc, char *argv[], bootm_headers_t *images)

(arch/arm/lib/bootm.c line 301)

->boot_jump_linux(images, flag); (line 318)

->static void boot_jump_linux(。。。。) (arch/arm/lib/bootm.c line 249)

->kernel_entry(0, machid, r2); (line 291) // linux kernel run

->parse_file_outer(); (common/main.c line 481) //进入u-boot命令行进行命令解析

->static int parse_file_outer(FILE *f) (common/hush.c line 3248)

->rcode = parse_stream_outer(&input, FLAG_PARSE_SEMICOLON); ( line 3260)

->static int parse_stream_outer(struct in_str *inp, int flag) (common/hush.cline 3150)

->run_list(ctx.list_head); (line 3179)

->static int run_list(struct pipe *pi) (common/hush.c line 1996)

->rcode = run_list_real(pi); (line 2002)

->static int run_list_real(struct pipe *pi) (common/hush.c line 1740)

->rcode = run_pipe_real(pi); (line 1854)

->static int run_pipe_real(struct pipe *pi) (common/hush.c line 1514)

->return cmd_process(flag, child->argc, child->argv, (line 1656)

->enum command_ret_t cmd_process(。。。) (common/command.c/line 499)

->cmdtp = find_cmd(argv[0]); (line 506)

->else if (cmdtp->cmd == do_bootd) { (line 518) //命令解析并执行完成

函数流程跟踪记录规则

有函数跳转时，另起一行并分级，然后加上文件路径和行号。

没有函数跳转时，另起一行不分级，然后加上行号即可，不需要文件路径，因为没有跳转。

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