mini6410板uboot的Armlinux.c

void do_bootm_linux (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[],
ulong addr, ulong *len_ptr, int verify)
{
ulong len = 0, checksum;
ulong initrd_start, initrd_end;
ulong data;
void (*theKernel)(int zero, int arch, uint params);
image_header_t *hdr = &header;
bd_t *bd = gd->bd;

#ifdef CONFIG_CMDLINE_TAG
char *commandline = getenv (“bootargs”);
#endif

theKernel = (void (*)(int, int, uint))ntohl(hdr->ih_ep);

/*
* Check if there is an initrd image
*/
if (argc >= 3) {
SHOW_BOOT_PROGRESS (9);

addr = simple_strtoul (argv[2], NULL, 16);

printf (“## Loading Ramdisk Image at %08lx …\n”, addr);

/* Copy header so we can blank CRC field for re-calculation */
#ifdef CONFIG_HAS_DATAFLASH
if (addr_dataflash (addr)) {
read_dataflash (addr, sizeof (image_header_t),
(char *) &header);
} else
#endif
memcpy (&header, (char *) addr,
sizeof (image_header_t));

if (ntohl (hdr->ih_magic) != IH_MAGIC) {
printf (“Bad Magic Number\n”);
SHOW_BOOT_PROGRESS (-10);
do_reset (cmdtp, flag, argc, argv);
}

data = (ulong) & header;
len = sizeof (image_header_t);

checksum = ntohl (hdr->ih_hcrc);
hdr->ih_hcrc = 0;

if (crc32 (0, (unsigned char *) data, len) != checksum) {
printf (“Bad Header Checksum\n”);
SHOW_BOOT_PROGRESS (-11);
do_reset (cmdtp, flag, argc, argv);
}

SHOW_BOOT_PROGRESS (10);

print_image_hdr (hdr);

data = addr + sizeof (image_header_t);
len = ntohl (hdr->ih_size);

#ifdef CONFIG_HAS_DATAFLASH
if (addr_dataflash (addr)) {
read_dataflash (data, len, (char *) CFG_LOAD_ADDR);
data = CFG_LOAD_ADDR;
}
#endif

if (verify) {
ulong csum = 0;

printf (”   Verifying Checksum … “);
csum = crc32 (0, (unsigned char *) data, len);
if (csum != ntohl (hdr->ih_dcrc)) {
printf (“Bad Data CRC\n”);
SHOW_BOOT_PROGRESS (-12);
do_reset (cmdtp, flag, argc, argv);
}
printf (“OK\n”);
}

SHOW_BOOT_PROGRESS (11);

if ((hdr->ih_os != IH_OS_LINUX) ||
(hdr->ih_arch != IH_CPU_ARM) ||
(hdr->ih_type != IH_TYPE_RAMDISK)) {
printf (“No Linux ARM Ramdisk Image\n”);
SHOW_BOOT_PROGRESS (-13);
do_reset (cmdtp, flag, argc, argv);
}

#if defined(CONFIG_B2) || defined(CONFIG_EVB4510) || defined(CONFIG_ARMADILLO)
/*
*we need to copy the ramdisk to SRAM to let Linux boot
*/
memmove ((void *) ntohl(hdr->ih_load), (uchar *)data, len);
data = ntohl(hdr->ih_load);
#endif /* CONFIG_B2 || CONFIG_EVB4510 */

/*
* Now check if we have a multifile image
*/
} else if ((hdr->ih_type == IH_TYPE_MULTI) && (len_ptr[1])) {
ulong tail = ntohl (len_ptr[0]) % 4;
int i;

SHOW_BOOT_PROGRESS (13);

/* skip kernel length and terminator */
data = (ulong) (&len_ptr[2]);
/* skip any additional image length fields */
for (i = 1; len_ptr[i]; ++i)
data += 4;
/* add kernel length, and align */
data += ntohl (len_ptr[0]);
if (tail) {
data += 4 – tail;
}

len = ntohl (len_ptr[1]);

} else {
/*
* no initrd image
*/
SHOW_BOOT_PROGRESS (14);

len = data = 0;
}

#ifdef     DEBUG
if (!data) {
printf (“No initrd\n”);
}
#endif

if (data) {
initrd_start = data;
initrd_end = initrd_start + len;
} else {
initrd_start = 0;
initrd_end = 0;
}

SHOW_BOOT_PROGRESS (15);

debug (“## Transferring control to Linux (at address %08lx) …\n”,
(ulong) theKernel);

#if defined (CONFIG_SETUP_MEMORY_TAGS) || \
defined (CONFIG_CMDLINE_TAG) || \
defined (CONFIG_INITRD_TAG) || \
defined (CONFIG_SERIAL_TAG) || \
defined (CONFIG_REVISION_TAG) || \
defined (CONFIG_LCD) || \
defined (CONFIG_VFD)
setup_start_tag (bd);
#ifdef CONFIG_SERIAL_TAG
setup_serial_tag (&params);
#endif
#ifdef CONFIG_REVISION_TAG
setup_revision_tag (&params);
#endif
#ifdef CONFIG_SETUP_MEMORY_TAGS
setup_memory_tags (bd);
#endif
#ifdef CONFIG_CMDLINE_TAG
setup_commandline_tag (bd, commandline);
#endif
#ifdef CONFIG_INITRD_TAG
if (initrd_start && initrd_end)
setup_initrd_tag (bd, initrd_start, initrd_end);
#endif
#if defined (CONFIG_VFD) || defined (CONFIG_LCD)
setup_videolfb_tag ((gd_t *) gd);
#endif
setup_end_tag (bd);
#endif

/* we assume that the kernel is in place */
printf (“\nStarting kernel …\n\n”);

#ifdef CONFIG_USB_DEVICE
{
extern void udc_disconnect (void);
udc_disconnect ();
}
#endif

cleanup_before_linux ();

theKernel (0, bd->bi_arch_number, bd->bi_boot_params);              /*此处开始运行内核的第一个函数，就是哪个linux内核的head.S里面定义的start段的第一条指令。其参数为r0：固定0，r1：唯一标记的板架构号，r2：板启动参数，这两个参数定义在Mini6410.c的board_init函数中。*/
}