rpi eeprom decode

55aaf00f

00000000  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
*
00000200  00 b0 00 01 f0 81 00 c0  e0 00 00 6d 82 18 0d 1f  |...........m....|
00000210  1d c0 41 07 18 e8 00 e8  00 80 19 e8 67 e8 00 80  |..A.........g...|
00000220  31 68 f9 c0 01 cf 2d 1f  1d c0 40 07 18 e8 00 e8  |1h....-...@.....|
...

bootconf.txt

[all]
BOOT_UART=0
WAKE_ON_GPIO=1
POWER_OFF_ON_HALT=0
DHCP_TIMEOUT=45000
DHCP_REQ_TIMEOUT=4000
TFTP_FILE_TIMEOUT=30000
TFTP_IP=
BOOT_ORDER=0x1
SD_BOOT_MAX_RETRIES=3
NET_BOOT_MAX_RETRIES=5
[none]
FREEZE_VERSION=0

default.nix

with import <nixpkgs> {};

let
  myghc = haskellPackages.ghcWithPackages (ps: with ps; [ formatting ]);
in runCommand "extractor" { buildInputs = [ myghc ]; } ''
  mkdir -pv $out/bin
  ghc ${./extractor.hs} -o $out/bin/extractor
''

extractor.hs

{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE NamedFieldPuns #-}

module Main where

import Data.Binary
import Data.Binary.Get
import qualified Data.ByteString as BS
import GHC.Generics
import Control.Applicative
import System.Environment
import Formatting ((%), sformat, hex, shown, stext)
import qualified Data.Text as T
import qualified Data.Text.Encoding as T

data FirmwareFile = FirmwareFile
  { firmwareEntries :: [ Entry ]
  } deriving (Generic, Show)

instance Binary FirmwareFile where
  get = FirmwareFile <$> many readEntry
  put = undefined

data Entry = Entry
  { entryOffset :: ByteOffset
  , entryMagic :: Word32
  , entrySize :: Word32
  , entryBody :: BS.ByteString
  , entryPadding :: ByteOffset
  } | FileEntry
  { entryFileMagic :: Word32
  , entryFileName :: T.Text
  , entryFileBody :: BS.ByteString
  } deriving Show

readEntry :: Get Entry
readEntry = do
  offset <- bytesRead
  magic <- getWord32be
  len <- getWord32be
  body <- getByteString $ fromIntegral len
  tailOffset <- bytesRead
  let
    remainder = tailOffset `mod` 8
    paddingLen = if remainder == 0 then 0 else (8 - remainder)
  padding <- getByteString $ fromIntegral paddingLen
  if ( (magic == 0x55aaf22f) || (magic == 0x55aaf11f) )
    then do
      let
        filename :: T.Text
        filename = T.decodeUtf8 $ BS.takeWhile (\c -> c /= 0) $ BS.take 16 body
        filebody = BS.drop 16 body
      pure $ FileEntry magic filename filebody
    else
      pure $ Entry offset magic len body tailOffset

decodeFirmware :: FilePath -> IO FirmwareFile
decodeFirmware = decodeFile

main :: IO ()
main = do
  args <- getArgs
  let
    prettyPrintEntry :: Entry -> IO ()
    prettyPrintEntry Entry{entryMagic, entryBody} = do
      let
        formatter = "Entry magic=" % hex % " initial_body=" % shown
      putStrLn $ T.unpack $ sformat formatter entryMagic (BS.take 32 entryBody)
    prettyPrintEntry FileEntry{entryFileMagic, entryFileName, entryFileBody} = do
      let
        formatter1 = "File Entry magic=" % hex % " name=" % stext % " body=" % shown
        formatter2 = "File Entry magic=" % hex % " name=" % stext % " body=hidden"
        go2 = putStrLn $ T.unpack $ sformat formatter1 entryFileMagic entryFileName (BS.take 100 entryFileBody)
        go3 = putStrLn $ T.unpack $ sformat formatter2 entryFileMagic entryFileName
      case entryFileName of
        "bootconf.txt" -> go2
        _ -> go3
    go :: [String] -> IO ()
    go [file] = do
      parsed <- decodeFirmware file
      mapM_ prettyPrintEntry (firmwareEntries parsed)
      mapM_ extractFiles (firmwareEntries parsed)
  print "hello world"
  go args

extractFiles :: Entry -> IO ()
extractFiles Entry{entryMagic, entryBody}
  | entryMagic == 0x55aaf00f = do
    BS.writeFile "main-body.bin" entryBody
  | otherwise = pure ()
extractFiles FileEntry{entryFileName, entryFileBody} = do
  BS.writeFile (T.unpack entryFileName) entryFileBody

gistfile1.txt

$ ./result/bin/extractor pieeprom-2019-10-16.bin
"hello world"
Entry magic=55aaf00f initial_body="\NUL\NUL\NUL\NUL\NUL\NUL\NUL\NUL\NUL\NUL\NUL\NUL\NUL\NUL\NUL\NUL\NUL\NUL\NUL\NUL\NUL\NUL\NUL\NUL\NUL\NUL\NUL\NUL\NUL\NUL\NUL\NUL"
Entry magic=55aafeef initial_body="\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255"
File Entry magic=55aaf22f name=memsys00.bin body=hidden
File Entry magic=55aaf22f name=memsys01.bin body=hidden
File Entry magic=55aaf22f name=memsys02.bin body=hidden
File Entry magic=55aaf22f name=memsys03.bin body=hidden
File Entry magic=55aaf22f name=memsys04.bin body=hidden
File Entry magic=55aaf22f name=memsys05.bin body=hidden
File Entry magic=55aaf22f name=memsys06.bin body=hidden
File Entry magic=55aaf22f name=memsys07.bin body=hidden
File Entry magic=55aaf22f name=mcb.bin body=hidden
Entry magic=55aafeef initial_body="\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255\255"
File Entry magic=55aaf11f name=bootconf.txt body="[all]\nBOOT_UART=0\nWAKE_ON_GPIO=1\nPOWER_OFF_ON_HALT=0\nDHCP_TIMEOUT=45000\nDHCP_REQ_TIMEOUT=4000\nTFTP_F"

gistfile2.txt

-rw-r--r-- 1 clever users  61K Nov 11 19:29 main-body.bin
-rw-r--r-- 1 clever users 3.8K Nov 11 19:29 mcb.bin
-rw-r--r-- 1 clever users  21K Nov 11 19:29 memsys00.bin
-rw-r--r-- 1 clever users  21K Nov 11 19:29 memsys01.bin
-rw-r--r-- 1 clever users  21K Nov 11 19:29 memsys02.bin
-rw-r--r-- 1 clever users  21K Nov 11 19:29 memsys03.bin
-rw-r--r-- 1 clever users  21K Nov 11 19:29 memsys04.bin
-rw-r--r-- 1 clever users  21K Nov 11 19:29 memsys05.bin
-rw-r--r-- 1 clever users  21K Nov 11 19:29 memsys06.bin
-rw-r--r-- 1 clever users  21K Nov 11 19:29 memsys07.bin

mcb.bin

00000000  1c 00 00 00 40 06 00 00  80 0c 00 00 08 00 00 00  |....@...........|
00000010  00 00 00 00 00 00 00 00  98 00 00 00 ef a6 32 01  |..............2.|
00000020  00 00 00 00 00 00 00 00  89 4d 3a ea 02 02 00 00  |.........M:.....|
00000030  02 3d 00 00 21 5c 10 00  b0 11 27 00 50 b2 00 00  |.=..!\....'.P...|
...

@jpmorrison the vl805 firmware inside this eeprom is in a different format, and cant be flashed to the vl805 eeprom

it must instead be sideloaded at runtime, https://github.com/librerpi/rpi-open-firmware/blob/master/docs/vl805.txt partially explains how