multiboot: Refactor boot data validation, add version numbers

Instead of verifying the CRC before every access of the boot data,
verify the CRC once at startup and set a flag to indicate the boot
data is valid.

Also add a framework to support multiple boot protocol versions.
Firmware declares the maximum supported protocol version using a
version byte in the boot data header. The bootloader chooses the
highest version supported by it and the firmware when deciding
what boot protocol to use.

Change-Id: I810194625dc0833f026d2a23b8d64ed467fa6aca

1 files changed, 3 insertions, 6 deletions

diff --git a/firmware/rolo.c b/firmware/rolo.c
index a3e6d5c2b9..1b37b6f771 100644
--- a/firmware/rolo.c
+++ b/firmware/rolo.c
@@ -250,12 +250,9 @@ int rolo_load(const char* filename)
 
     err = LOAD_FIRMWARE(filebuf, filename, filebuf_size);
 #if defined(HAVE_BOOTDATA) && !defined(SIMULATOR)
-    /* write the bootdata as if rolo were the bootloader */
-    unsigned int crc = 0;
-    if (strcmp(filename, BOOTDIR "/" BOOTFILE) == 0)
-        crc = crc_32(boot_data.payload, boot_data.length, 0xffffffff);
-
-    if(crc > 0 && crc == boot_data.crc)
+    /* write the bootdata as if rolo were the bootloader
+     * FIXME: this won't work for root redirect... */
+    if (!strcmp(filename, BOOTDIR "/" BOOTFILE) && boot_data_valid)
         write_bootdata(filebuf, filebuf_size, boot_data.boot_volume); /* rb-loader.c */
 #endif