

- #HEX FILE CRC 16 CALCULATOR CHECKSUM HOW TO#
- #HEX FILE CRC 16 CALCULATOR CHECKSUM CODE#
- #HEX FILE CRC 16 CALCULATOR CHECKSUM MAC#
#HEX FILE CRC 16 CALCULATOR CHECKSUM CODE#
all comments here are original to factory-supplied code (though re-aligned for readability below).It also shows how the bootloader validates the magic number and two different crc values found inside envfs_super, as well as an additional magic number found inside a struct of type envfs_inode (which itself is loaded from the bytes following envfs_super).įrom the file barebox-2011.06.0/include/envfs.h That file shows how a struct of type envfs_super is populated from the first few bytes of partition 7 (or 8). That string appears only in the file barebox-2011.06.0/commands/sataenv.c. Using an IDE (or grep), search within barebox-2011.06.0/ subdir inside WD GPL Source Code for the string wrong crc on env data. WHERE DOES "wrong crc on env data" OCCUR? the resulting k1m0.env passes crc validation during boot on actual hardware.edited only the two “crc” fields based on a modified k1m0.env (one byte of the content changed, size did not).the results are indistinguishable from the original, confirmed using hexdump (usage shown below).edited the four “size” and “crc” fields described below for an unmodified factory k1m0.env.Using the instructions in this guide, I have successfully The source code files referenced in this guide are found inside WD GPL Source Code available on the support downloads page.Ī binary representation of a struct named envfs_super and another struct named envfs_inode appear at the start of the kernel config partitions (required by bootloader) - thought process follows.
#HEX FILE CRC 16 CALCULATOR CHECKSUM MAC#
# - you can find the placeholder mac address by searching barebox source codeĬommandline:$console=ttyS0,115200n8, init=/sbin/init rootfstype=ext4 rw noinitrd mac_addr=00:11:22:33:44:55 model= serial= board_test= btn_status=0

# - barebox appears to load a placeholder config if no config partitions pass crc # - notice how mac_addr is a bogus value and other values are blank Sataenv: partition 8 wrong crc on env data You may have landed here due to the following errors observed over UART during boot: sataenv: partition 7 wrong crc on env data
#HEX FILE CRC 16 CALCULATOR CHECKSUM HOW TO#

