U-Boot啟動Linux內核

日期：2017/3/1 10:24:08 编辑：Linux內核

1、

U_BOOT_CMD(
bootm, CFG_MAXARGS, 1,do_bootm,
"bootm - boot application image from memory\n",
"[addr [arg ...]]\n - boot application image stored in memory\n"
"\tpassing arguments 'arg ...'; when booting a Linux kernel,\n"
"\t'arg' can be the address of an initrd image\n"
#ifdef CONFIG_OF_FLAT_TREE
"\tWhen booting a Linux kernel which requires a flat device-tree\n"
"\ta third argument is required which is the address of the of the\n"
"\tdevice-tree blob. To boot that kernel without an initrd image,\n"
"\tuse a '-' for the second argument. If you do not pass a third\n"
"\ta bd_info struct will be passed instead\n"
#endif
);

根據上面可知：bootm命令的執行函數是do_bootm，函數的最大參數是CFG_MAXARGS。

U-Boot源代碼下載地址 http://www.linuxidc.com/Linux/2011-07/38897.htm

2、do_bootm函數源碼摘要：

SHOW_BOOT_PROGRESS (8);

#if defined(CONFIG_ZIMAGE_BOOT) || defined(CONFIG_IMAGE_BOOT)
after_header_check:
#endif
switch (hdr->ih_os) {
default: /* handled by (original) Linux case */
case IH_OS_LINUX:
#ifdef CONFIG_SILENT_CONSOLE
fixup_silent_linux();
#endif
do_bootm_linux (cmdtp, flag, argc, argv,
addr, len_ptr, verify);
break;
case IH_OS_NETBSD:
do_bootm_netbsd (cmdtp, flag, argc, argv,
addr, len_ptr, verify);
break;

#ifdef CONFIG_LYNXKDI
case IH_OS_LYNXOS:
do_bootm_lynxkdi (cmdtp, flag, argc, argv,
addr, len_ptr, verify);
break;
#endif

case IH_OS_RTEMS:
do_bootm_rtems (cmdtp, flag, argc, argv,
addr, len_ptr, verify);
break;

#if (CONFIG_COMMANDS & CFG_CMD_ELF)
case IH_OS_VXWORKS:
do_bootm_vxworks (cmdtp, flag, argc, argv,
addr, len_ptr, verify);
break;
case IH_OS_QNX:
do_bootm_qnxelf (cmdtp, flag, argc, argv,
addr, len_ptr, verify);
break;
#endif /* CFG_CMD_ELF */
#ifdef CONFIG_ARTOS
case IH_OS_ARTOS:
do_bootm_artos (cmdtp, flag, argc, argv,
addr, len_ptr, verify);
break;
#endif
}