Move the code which reads a partition into its own function. Add a constant for the number of bytes to 'probe' at the start of the partition.
Signed-off-by: Simon Glass sjg@chromium.org ---
boot/bootmeth_cros.c | 66 +++++++++++++++++++++++++++++++++----------- 1 file changed, 50 insertions(+), 16 deletions(-)
diff --git a/boot/bootmeth_cros.c b/boot/bootmeth_cros.c index 6179a547f74a..f6fb521f2065 100644 --- a/boot/bootmeth_cros.c +++ b/boot/bootmeth_cros.c @@ -23,6 +23,8 @@ #include <linux/sizes.h>
enum { + PROBE_SIZE = SZ_4K, /* initial bytes read from partition */ + /* Offsets in the kernel-partition header */ KERN_START = 0x4f0, KERN_SIZE = 0x518, @@ -77,6 +79,51 @@ static int copy_cmdline(const char *from, const char *uuid, char **bufp) return 0; }
+/** + * scan_part() - Scan a kernel partition to see if has a ChromeOS header + * + * This reads the first PROBE_SIZE of a partition, loookng for CHROMEOS + * + * @blk: Block device to scan + * @partnum: Partition number to scan + * @info: Please to put partition info + * @hdrp: Return allocated keyblock header on success + */ +static int scan_part(struct udevice *blk, int partnum, + struct disk_partition *info, void **hdrp) +{ + struct blk_desc *desc = dev_get_uclass_plat(blk); + struct vb2_keyblock *hdr; + ulong num_blks; + int ret; + + ret = part_get_info(desc, partnum, info); + if (ret) + return log_msg_ret("part", ret); + + /* Make a buffer for the header information */ + num_blks = PROBE_SIZE >> desc->log2blksz; + log_debug("Reading header, blk=%s, start=%lx, blocks=%lx\n", + blk->name, (ulong)info->start, num_blks); + hdr = memalign(SZ_1K, PROBE_SIZE); + if (!hdr) + return log_msg_ret("hdr", -ENOMEM); + ret = blk_read(blk, info->start, num_blks, hdr); + if (ret != num_blks) { + free(hdr); + return log_msg_ret("inf", -EIO); + } + + if (memcmp("CHROMEOS", hdr, 8)) { + free(hdr); + return -ENOENT; + } + + *hdrp = hdr; + + return 0; +} + static int cros_read_bootflow(struct udevice *dev, struct bootflow *bflow) { struct blk_desc *desc = dev_get_uclass_plat(bflow->blk); @@ -93,23 +140,10 @@ static int cros_read_bootflow(struct udevice *dev, struct bootflow *bflow) return log_msg_ret("max", -ENOENT);
/* Check partition 2 */ - ret = part_get_info(desc, 2, &info); + ret = scan_part(bflow->blk, 2, &info, &hdr); if (ret) - return log_msg_ret("part", ret); - - /* Make a buffer for the header information */ - num_blks = SZ_4K >> desc->log2blksz; - log_debug("Reading header, blk=%s, start=%lx, blocks=%lx\n", - bflow->blk->name, (ulong)info.start, num_blks); - hdr = memalign(SZ_1K, SZ_4K); - if (!hdr) - return log_msg_ret("hdr", -ENOMEM); - ret = blk_read(bflow->blk, info.start, num_blks, hdr); - if (ret != num_blks) - return log_msg_ret("inf", -EIO); - - if (memcmp("CHROMEOS", hdr, 8)) - return -ENOENT; + return log_msg_ret("scan", ret); + bflow->part = 2;
log_info("Header at %lx\n", (ulong)map_to_sysmem(hdr)); start = *(u32 *)(hdr + KERN_START);