vbe: Move reading the nvdata into the common file
All VBE methods read non-volatile data, so move this function into a
common file.
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/boot/vbe_common.c b/boot/vbe_common.c
index 8bbcc37..672878f 100644
--- a/boot/vbe_common.c
+++ b/boot/vbe_common.c
@@ -9,6 +9,7 @@
#include <blk.h>
#include <memalign.h>
#include <spl.h>
+#include <u-boot/crc.h>
#include "vbe_common.h"
int vbe_get_blk(const char *storage, struct udevice **blkp)
@@ -59,3 +60,43 @@
return 0;
}
+
+int vbe_read_nvdata(struct udevice *blk, ulong offset, ulong size, u8 *buf)
+{
+ uint hdr_ver, hdr_size, data_size, crc;
+ const struct vbe_nvdata *nvd;
+
+ /* we can use an assert() here since we already read only one block */
+ assert(size <= MMC_MAX_BLOCK_LEN);
+
+ /*
+ * We can use an assert() here since reading the wrong block will just
+ * cause invalid state to be (safely) read. If the crc passes, then we
+ * obtain invalid state and it will likely cause booting to fail.
+ *
+ * VBE relies on valid values being in U-Boot's devicetree, so this
+ * should not every be wrong on a production device.
+ */
+ assert(!(offset & (MMC_MAX_BLOCK_LEN - 1)));
+
+ if (offset & (MMC_MAX_BLOCK_LEN - 1))
+ return log_msg_ret("get", -EBADF);
+ offset /= MMC_MAX_BLOCK_LEN;
+
+ if (blk_read(blk, offset, 1, buf) != 1)
+ return log_msg_ret("read", -EIO);
+ nvd = (struct vbe_nvdata *)buf;
+ hdr_ver = (nvd->hdr & NVD_HDR_VER_MASK) >> NVD_HDR_VER_SHIFT;
+ hdr_size = (nvd->hdr & NVD_HDR_SIZE_MASK) >> NVD_HDR_SIZE_SHIFT;
+ if (hdr_ver != NVD_HDR_VER_CUR)
+ return log_msg_ret("hdr", -EPERM);
+ data_size = 1 << hdr_size;
+ if (!data_size || data_size > sizeof(*nvd))
+ return log_msg_ret("sz", -EPERM);
+
+ crc = crc8(0, buf + 1, data_size - 1);
+ if (crc != nvd->crc8)
+ return log_msg_ret("crc", -EPERM);
+
+ return 0;
+}