convert_vfct.c

/*
 * convert_vfct.c - convert VFCT ACPI table into multiple ATOMBIOS roms
 *
 * Copyright (C) 2023 by @cleanbaja
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
 * and associated documentation files (the "Software"), to deal in the Software without restriction,
 * including without limitation the rights to use, copy, modify, merge, publish, distribute,
 * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all copies or
 * substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
 * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#include <stdint.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdio.h>
#include <sys/stat.h>
#include <sys/mman.h>

/*
 * NOTE: The expanded roms can be disassembled using the following tool...
 * https://github.com/cleanbaja/AtomDis
 */

#pragma pack(1)

struct acpi_header {
  char signature[4];
  uint32_t length;
  uint8_t  revision;
  uint8_t  checksum;
  uint8_t  oem[6];
  uint8_t  oem_table[8];
  uint32_t oem_revision;
  uint32_t creator_id;
  uint32_t creator_revision;
};

struct vfct_header {
  uint32_t  pci_bus;
  uint32_t  pci_dev;
  uint32_t  pci_func;
  uint16_t  pci_vendor_id;
  uint16_t  pci_device_id;
  uint16_t  ssvid;
  uint16_t  ssid;
  uint32_t  revision;
  uint32_t  length;
};

struct vbios_content {
  struct vfct_header hdr;
  uint8_t content[];
};

typedef struct acpi_vfct {
  struct acpi_header hdr;
  uint8_t uuid[16];
  uint32_t vbios_offset;
  uint32_t lib1_offset;
  uint32_t rsvd[4];
} acpi_vfct_t;

#pragma pack()

void dump_bios_images(acpi_vfct_t* region) {
    uint32_t off = region->vbios_offset;
    int index = 1;

    while ((off + sizeof(struct vfct_header)) < region->hdr.length) {
        struct vbios_content* vbios = (struct vbios_content *)((uintptr_t)region + off);
        off += vbios->hdr.length + sizeof(struct vfct_header);

        printf(
            "convert_vfct: found ATOMBIOS for PCI device %02d:%02d.%d (id=%x:%x)\n",
            vbios->hdr.pci_bus, vbios->hdr.pci_dev, vbios->hdr.pci_func,
            vbios->hdr.pci_vendor_id, vbios->hdr.pci_device_id
        );

        int rom_fd = 0;
        if (index == 1) {
            rom_fd = open("vbios.bin", O_WRONLY | O_CREAT, 0644);
        } else {
            char filename_buf[256] = {0};
            snprintf(filename_buf, 256, "vbios%d.bin", index);
            rom_fd = open(filename_buf, O_WRONLY | O_CREAT, 0644);
        }

        index++;
        write(rom_fd, vbios->content, vbios->hdr.length);
        close(rom_fd);
    }
}

int main(int argc, char** argv) {
    if (argc < 2)
        return 0;

    int fd = open(argv[1], O_RDONLY);
    struct stat stat;
    fstat(fd, &stat);

    acpi_vfct_t* region = (acpi_vfct_t *)mmap(NULL, stat.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
    struct vbios_content* vbios = (struct vbios_content *)((uintptr_t)region + region->vbios_offset);

    dump_bios_images(region);
    munmap(region, stat.st_size);
    close(fd);

    return 0;
}