bootstd: cros: Decode some kernel preamble fields

Decode the kernel start and size using the structures provided. This
accesses the same data, just in a cleaner way.

Add some logging for some of the fields in the kernel preamble.

Signed-off-by: Simon Glass <sjg@chromium.org>

diff --git a/boot/bootmeth_cros.c b/boot/bootmeth_cros.c
index 7b25042bfe56ebc7fc444639b163d71dc69fbef7..2a745621e30e86a97425a7462dc3ac99cbb371cd 100644 (file)
--- a/boot/bootmeth_cros.c
+++ b/boot/bootmeth_cros.c
@@ -27,10 +27,6 @@
 enum {
        PROBE_SIZE      = SZ_4K,        /* initial bytes read from partition */
 
-       /* Offsets in the kernel-partition header */
-       KERN_START      = 0x4f0,
-       KERN_SIZE       = 0x518,
-
        SETUP_OFFSET    = 0x1000,       /* bytes before base */
        CMDLINE_OFFSET  = 0x2000,       /* bytes before base */
        OFFSET_BASE     = 0x100000,     /* assumed kernel load-address */
@@ -93,7 +89,7 @@ static int copy_cmdline(const char *from, const char *uuid, char **bufp)
  * @hdrp: Return allocated keyblock header on success
  */
 static int scan_part(struct udevice *blk, int partnum,
-                    struct disk_partition *info, void **hdrp)
+                    struct disk_partition *info, struct vb2_keyblock **hdrp)
 {
        struct blk_desc *desc = dev_get_uclass_plat(blk);
        struct vb2_keyblock *hdr;
@@ -130,11 +126,14 @@ static int scan_part(struct udevice *blk, int partnum,
 static int cros_read_bootflow(struct udevice *dev, struct bootflow *bflow)
 {
        struct blk_desc *desc = dev_get_uclass_plat(bflow->blk);
-       ulong base, start, size, setup, cmdline, num_blks, kern_base;
+       ulong base, start, setup, cmdline, num_blks, kern_base;
+       const struct vb2_kernel_preamble *preamble;
+       ulong body_offset, body_size;
        struct disk_partition info;
        const char *uuid = NULL;
-       void *buf, *hdr;
+       struct vb2_keyblock *hdr;
        int part, ret;
+       void *buf;
 
        log_debug("starting, part=%d\n", bflow->part);
 
@@ -155,18 +154,39 @@ static int cros_read_bootflow(struct udevice *dev, struct bootflow *bflow)
 
        log_info("Selected parition %d, header at %lx\n", bflow->part,
                 (ulong)map_to_sysmem(hdr));
-       start = *(u32 *)(hdr + KERN_START);
-       size = ALIGN(*(u32 *)(hdr + KERN_SIZE), desc->blksz);
-       log_debug("Reading start %lx size %lx\n", start, size);
-       bflow->size = size;
-
-       buf = memalign(SZ_1K, size);
+       preamble = (void *)hdr + hdr->keyblock_size;
+       log_debug("Kernel preamble at %lx, version major %x, minor %x\n",
+                 (ulong)map_to_sysmem(preamble),
+                 preamble->header_version_major,
+                 preamble->header_version_minor);
+
+       start = (ulong)preamble->bootloader_address;
+       log_debug("  - load_address %lx, bl_addr %lx, bl_size %lx\n",
+                 (ulong)preamble->body_load_address,
+                 (ulong)preamble->bootloader_address,
+                 (ulong)preamble->bootloader_size);
+
+       body_offset = hdr->keyblock_size + preamble->preamble_size;
+       body_size = preamble->body_signature.data_size;
+       log_debug("Kernel body at %lx size %lx\n", body_offset, body_size);
+       bflow->size = body_size;
+
+       buf = memalign(SZ_1K, body_size);
        if (!buf)
                return log_msg_ret("buf", -ENOMEM);
-       num_blks = size >> desc->log2blksz;
-       log_debug("Reading data, blk=%s, start=%lx, blocks=%lx\n",
-                 bflow->blk->name, (ulong)info.start, num_blks);
-       ret = blk_read(bflow->blk, (ulong)info.start + 0x80, num_blks, buf);
+
+       /* Check that the header is not smaller than permitted */
+       if (body_offset < PROBE_SIZE)
+               return log_msg_ret("san", EFAULT);
+
+       /* Read kernel body */
+       num_blks = body_size >> desc->log2blksz;
+       log_debug("Reading body to %lx, blk=%s, size=%lx, blocks=%lx\n",
+                 (ulong)map_to_sysmem(buf), bflow->blk->name, body_size,
+                 num_blks);
+       ret = blk_read(bflow->blk,
+                      info.start + (body_offset >> desc->log2blksz),
+                      num_blks, buf);
        if (ret != num_blks)
                return log_msg_ret("inf", -EIO);
        base = map_to_sysmem(buf);