[UBOOT] AM335x bootm trace（u-boot-2011.09）

do_run
{
	arg = getenv (argv[i]));////run的参数从环境变量中获得
	run_command (arg, flag);
}

bootcmd=run nand_boot
			nand_boot=1.echo Booting from nand ...; 
					  2.run nand_args; 
					  		nand_args=1.run bootargs_defaults;
		                   				    bootargs_defaults=setenv bootargs console=${console} ${optargs}		  		
					  				  2.setenv bootargs ${bootargs} root=${nand_root} noinitrd rootfstype=${nand_root_fs_type} ip=${ip_method}
*bootargs= console=ttyO0,115200n8 root=ubi0:rootfs rw ubi.mtd=3,2048 noinitrd rootfstype=ubifs rootwait=1 ip=none
					  3.nand read.i ${kloadaddr} ${nand_src_addr} ${nand_img_siz};
					  				  kloadaddr=0x80007fc0;nand_src_addr=0x280000;nand_img_siz=0x400000/4MB
					  4.bootm ${kloadaddr}
					 
					 
bootm 0x80007fc0=0x80008000-0x40
	do_bootm
	{
		bootm_start
		{
			bootm_start_lmb//??
			boot_get_kernel
			{
				genimg_get_format ((void *)img_addr); return IMAGE_FORMAT_LEGACY
				image_get_kernel (img_addr, images->verify)
				{
					image_check_magic
					image_check_hcrc//对image_header进行crc校验
					image_print_contents
					if (verify) image_check_dcrc//对数据区进行crc校验
					image_check_target_arch
				}	
				case IH_TYPE_KERNEL:
				images.os.image_start : *os_data = image_get_data (hdr);//返回内核的入口点地址,0x80008000
				images.os.image_len   : *os_len = image_get_data_size (hdr);
				
				return (void *)img_addr;//0x80007fc0
			}
			images.os.type = image_get_type (os_hdr);
			images.os.comp = image_get_comp (os_hdr);
			images.os.os = image_get_os (os_hdr);
			images.os.end = image_get_image_end (os_hdr);
			images.os.load = image_get_load (os_hdr);
			
			/* find kernel entry point */
			images.ep = image_get_ep (&images.legacy_hdr_os_copy);//0x80008000
			
			boot_get_ramdisk//return 0,No init Ramdisk
			
			images.os.start = (ulong)os_hdr;//0x80007fc0
			images.state = BOOTM_STATE_START;
			return 0;
		}
		disable_interrupts();
		usb_stop();
		bootm_load_os(images.os, &load_end, 1);
		{
			flush_cache(load, (*load_end - load) * sizeof(ulong));
			return BOOTM_ERR_OVERLAP;
		}
		lmb_reserve
		boot_fn = boot_os[images.os.os];//boot_os[5]=do_bootm_linux
		arch_preboot_os();

		boot_fn(0, argc, argv, &images);//do_bootm_linux
		{
			int	machid = bd->bi_arch_number;//3589
			char *commandline = getenv ("bootargs");
			//console=ttyO0,115200n8 root=ubi0:rootfs rw ubi.mtd=3,2048 noinitrd rootfstype=ubifs rootwait=1 ip=none	
			kernel_entry = (void (*)(int, int, uint))images->ep;//0x80008000
			
			//TAG 设置
			setup_start_tag (bd);
			{
				params = (struct tag *) bd->bi_boot_params;//0x80000100
				params->hdr.tag = ATAG_CORE;
				params->hdr.size = tag_size (tag_core);
				params->u.core.flags = 0;
				params->u.core.pagesize = 0;
				params->u.core.rootdev = 0;
				params = tag_next (params);
			}
			setup_memory_tags (bd);
			setup_commandline_tag (bd, commandline);
			{
				params->hdr.tag = ATAG_CMDLINE;
				params->hdr.size =(sizeof (struct tag_header) + strlen (p) + 1 + 4) >> 2;
				strcpy (params->u.cmdline.cmdline, p);
			    params = tag_next (params);
			}
			setup_end_tag(bd);
			announce_and_cleanup();
			{
				cleanup_before_linux();*******
				{
					
				}
			}
			kernel_entry(0, machid, bd->bi_boot_params);//machid=3589;bd->bi_boot_params=0x80000100,保存tag
			/* does not return */ //跳转到Linux kernel执行
		}
	}