raspberrypi4-eeprom.imhex

#pragma endian big

#include <std/mem.pat>

// Some useful links found while developing this pattern file
// https://github.com/raspberrypi/rpi-eeprom/blob/d774d5794cc63248e559bba201630d00a6e35762/rpi-eeprom-config#L228
// https://github.com/raspberrypi/rpi-eeprom/issues/153
// https://git.venev.name/hristo/rpi-eeprom-compress

u32 image_size = 512 * 1024; // This is the size of the EEPROM
u32 magic_mask = 0xfffff00f;
u32 file_header_len = 20;
u32 file_name_len = 12;

u32 erase_align_size = 4096;
u32 max_file_size = erase_align_size - file_header_len;

enum MAGIC: u32 {
    magic = 0x55aaf00f, // I am not sure what this one is
    pad = 0x55aafeef,
    file_magic = 0x55aaf11f,
    // Compress with the following
    // https://git.venev.name/hristo/rpi-eeprom-compress.git
    // Decompress with the following
    // https://git.venev.name/hristo/rpi-eeprom-compress/tree/uncompress.c
    compressed_file = 0x55aaf33f,
    end = 0xffffffff,
};

struct ImageSection {
    MAGIC magic;
    if (magic == MAGIC::end) {
        continue;
    } else {
        // Padding, Files and Compressed Files share these
        u32 size;
        u8 data[size];
        std::mem::AlignTo<8>;
        // Both files and compressed files have a structure
        // to their data
        if (magic == MAGIC::file_magic || magic == MAGIC::compressed_file) {
            // File name is 12 bytes, padded with 0x0 if less.
            char file_name[file_name_len] @ addressof(data);
            // Todo what are the 4 bytes between the file name and the data
            u8 file_data[size - file_name_len] @ addressof(data) + file_name_len + 4;
        }
    }
};

struct ReservedPage {
    u8 data[erase_align_size];
};

ImageSection sections[while(std::mem::read_unsigned($, 4) != MAGIC::end)] @ 0x0;

// Our image should always be the same size as we flash the whole EEPROM
// every time.
ReservedPage reserved_page @ image_size - erase_align_size;