do_bootm-如何使用-有什么中文资料面包板社区

/*uboot一般都是调用do_bootm命令来引导内核，这个命令基本上就是判断类型然后跳转到do_bootm_linux函数也是做了一些简单注释关键我也是简单看了一下留个笔记有问题还望指正*/ ulong load_addr = CFG_LOAD_ADDR; /* Default Load Address */ //CFG_LOAD_ADDR 这个宏一般在smdk2410定义，为内核的入口地址，就是内核执行的第一个函数的地址， //这个地址首先被赋给uimage的64字节结构体的hdr-ih_ep，然后又赋给了kernel这个函数指针，最后通过 //theKernel (0, bd-bi_arch_number, bd-bi_boot_params);这个函数来进入linux内核。 int do_bootm (cmd_tbl_t *cmdtp, int flag, int argc, char *argv ); image_header_t *hdr = header; s = getenv ("verify"); verify = (s (*s == 'n')) ? 0 : 1; if (argc 2) { addr = load_addr; } else { addr = simple_strtoul(argv , NULL, 16); } //如果argc小于2 说明就输入了一个bootm参数没有参数则使用默认地址 SHOW_BOOT_PROGRESS (1); printf ("## Booting image at %08lx ...\n", addr); /* Copy header so we can blank CRC field for re-calculation 。。。。crc校验*/ #ifdef CONFIG_HAS_DATAFLASH if (addr_dataflash(addr)){ read_dataflash(addr, sizeof(image_header_t), (char *)header); } else #endif memmove (header, (char *)addr, sizeof(image_header_t)); if (ntohl(hdr-ih_magic) != IH_MAGIC) { #ifdef __I386__ /* correct image format not implemented yet - fake it */ if (fake_header(hdr, (void*)addr, -1) != NULL) { /* to compensate for the addition below */ addr -= sizeof(image_header_t); /* turnof verify, * fake_header() does not fake the data crc */ verify = 0; } else #endif /* __I386__ */ { puts ("Bad Magic Number\n"); SHOW_BOOT_PROGRESS (-1); return 1; } } SHOW_BOOT_PROGRESS (2); data = (ulong)header; len = sizeof(image_header_t); checksum = ntohl(hdr-ih_hcrc); hdr-ih_hcrc = 0; if (crc32 (0, (uchar *)data, len) != checksum) { puts ("Bad Header Checksum\n"); SHOW_BOOT_PROGRESS (-2); return 1; } SHOW_BOOT_PROGRESS (3); #ifdef CONFIG_HAS_DATAFLASH if (addr_dataflash(addr)){ len = ntohl(hdr-ih_size) + sizeof(image_header_t); read_dataflash(addr, len, (char *)CFG_LOAD_ADDR); addr = CFG_LOAD_ADDR; } #endif /* for multi-file images we need the data part, too */ print_image_hdr ((image_header_t *)addr); data = addr + sizeof(image_header_t); len = ntohl(hdr-ih_size); if (verify) { puts (" Verifying Checksum ... "); if (crc32 (0, (uchar *)data, len) != ntohl(hdr-ih_dcrc)) { printf ("Bad Data CRC\n"); SHOW_BOOT_PROGRESS (-3); return 1; } puts ("OK\n"); } SHOW_BOOT_PROGRESS (4); len_ptr = (ulong *)data; #if defined(__PPC__) if (hdr-ih_arch != IH_CPU_PPC) #elif defined(__ARM__)//hdr为uimage64字节结构体变量。 if (hdr-ih_arch != IH_CPU_ARM) #elif defined(__I386__) if (hdr-ih_arch != IH_CPU_I386) #elif defined(__mips__) if (hdr-ih_arch != IH_CPU_MIPS) #elif defined(__nios__) if (hdr-ih_arch != IH_CPU_NIOS) #elif defined(__M68K__) if (hdr-ih_arch != IH_CPU_M68K) #elif defined(__microblaze__) if (hdr-ih_arch != IH_CPU_MICROBLAZE) #elif defined(__nios2__) if (hdr-ih_arch != IH_CPU_NIOS2) #elif defined(__blackfin__) if (hdr-ih_arch != IH_CPU_BLACKFIN) #elif defined(__avr32__) if (hdr-ih_arch != IH_CPU_AVR32) #else # error Unknown CPU type #endif { printf ("Unsupported Architecture 0x%x\n", hdr-ih_arch); SHOW_BOOT_PROGRESS (-4); return 1; } SHOW_BOOT_PROGRESS (5); //判断文件类型此处应该为kernel 各种类型在includ/image.h中有解释。 switch (hdr-ih_type) { case IH_TYPE_STANDALONE: name = "Standalone Application"; /* A second argument overwrites the load address */ if (argc 2) { hdr-ih_load = htonl(simple_strtoul(argv , NULL, 16)); } break; case IH_TYPE_KERNEL://kernel name = "Kernel Image"; break; case IH_TYPE_MULTI: name = "Multi-File Image"; len = ntohl(len_ptr ); /* OS kernel is always the first image */ data += 8; /* kernel_len + terminator */ for (i=1; len_ptr ; ++i) data += 4; break; default: printf ("Wrong Image Type for %s command\n", cmdtp-name); SHOW_BOOT_PROGRESS (-5); return 1; } SHOW_BOOT_PROGRESS (6); /* * We have reached the point of no return: we are going to * overwrite all exception vector code, so we cannot easily * recover from any failures any more... */ iflag = disable_interrupts(); #ifdef CONFIG_AMIGAONEG3SE /* * We've possible left the caches enabled during * bios emulation, so turn them off again */ icache_disable(); invalidate_l1_instruction_cache(); flush_data_cache(); dcache_disable(); #endif //判断压缩格式，然后解压 switch (hdr-ih_comp) { case IH_COMP_NONE: if(ntohl(hdr-ih_load) == addr) { printf (" XIP %s ... ", name); } else { #if defined(CONFIG_HW_WATCHDOG) || defined(CONFIG_WATCHDOG) size_t l = len; void *to = (void *)ntohl(hdr-ih_load); void *from = (void *)data; printf (" Loading %s ... ", name); while (l 0) { size_t tail = (l CHUNKSZ) ? CHUNKSZ : l; WATCHDOG_RESET(); memmove (to, from, tail); to += tail; from += tail; l -= tail; } #else /* !(CONFIG_HW_WATCHDOG || CONFIG_WATCHDOG) */ memmove ((void *) ntohl(hdr-ih_load), (uchar *)data, len); #endif /* CONFIG_HW_WATCHDOG || CONFIG_WATCHDOG */ } break; case IH_COMP_GZIP: printf (" Uncompressing %s ... ", name); if (gunzip ((void *)ntohl(hdr-ih_load), unc_len, (uchar *)data, len) != 0) { puts ("GUNZIP ERROR - must RESET board to recover\n"); SHOW_BOOT_PROGRESS (-6); do_reset (cmdtp, flag, argc, argv); } break; #ifdef CONFIG_BZIP2 case IH_COMP_BZIP2: printf (" Uncompressing %s ... ", name); /* * If we've got less than 4 MB of malloc() space, * use slower decompression algorithm which requires * at most 2300 KB of memory. */ i = BZ2_bzBuffToBuffDecompress ((char*)ntohl(hdr-ih_load), unc_len, (char *)data, len, CFG_MALLOC_LEN (4096 * 1024), 0); if (i != BZ_OK) { printf ("BUNZIP2 ERROR %d - must RESET board to recover\n", i); SHOW_BOOT_PROGRESS (-6); udelay(100000); do_reset (cmdtp, flag, argc, argv); } break; #endif /* CONFIG_BZIP2 */ default: if (iflag) enable_interrupts(); printf ("Unimplemented compression type %d\n", hdr-ih_comp); SHOW_BOOT_PROGRESS (-7); return 1; } puts ("OK\n"); SHOW_BOOT_PROGRESS (7); switch (hdr-ih_type) { case IH_TYPE_STANDALONE: if (iflag) enable_interrupts(); /* load (and uncompress), but don't start if "autostart" * is set to "no" */ if (((s = getenv("autostart")) != NULL) (strcmp(s,"no") == 0)) { char buf ; sprintf(buf, "%lX", len); setenv("filesize", buf); return 0; } appl = (int (*)(int, char * ); return 0; case IH_TYPE_KERNEL: case IH_TYPE_MULTI: /* handled below */ break; default: if (iflag) enable_interrupts(); printf ("Can't boot image type %d\n", hdr-ih_type); SHOW_BOOT_PROGRESS (-8); return 1; } SHOW_BOOT_PROGRESS (8); //判断操作系统有linux vxworks等然后跳转到对应的执行函数中去 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);//这个函数在lib_arm/中的armlinux.c中 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 } SHOW_BOOT_PROGRESS (-9); #ifdef DEBUG puts ("\n## Control returned to monitor - resetting...\n"); do_reset (cmdtp, flag, argc, argv); #endif return 1; }

标签: do_bootm