I'm trying to get a backup of the bios of my desktop computer, but it fails with this message:

# flashrom  -V -p internal -r bios.rom
flashrom v0.9.9-91-g0bfa819 on Linux 4.13.0-0.bpo.1-amd64 (x86_64)
flashrom is free software, get the source code at https://flashrom.org

flashrom was built with libpci 3.5.2, GCC 6.3.0 20170516, little endian
Command line (3 args): /home/as/src/flashrom/flashrom -V -p internal
Using clock_gettime for delay loops (clk_id: 1, resolution: 1ns).
Initializing internal programmer
No coreboot table found.
Using Internal DMI decoder.
DMI string chassis-type: "Desktop"
DMI string system-manufacturer: "0000"
DMI string system-product-name: "OEM"
DMI string system-version: "OEM"
DMI string baseboard-manufacturer: "Foxconn"
DMI string baseboard-product-name: "G31MVP"
DMI string baseboard-version: "FAB:1.0"
Found ITE Super I/O, ID 0x8718 on port 0x2e
Found chipset "Intel ICH7/ICH7R" with PCI ID 8086:27b8.
Enabling flash write... Root Complex Register Block address = 0xfed1c000
Error accessing ICH RCRB, 0x4000 bytes at 0x00000000fed1c000
/dev/mem mmap failed: Operation not permitted
Error: Programmer initialization failed.

I tried with flashrom "v0.9.9-r1954" from debian/stable as well as the latest version from the git repository. Both gave the same results.

Here are the results of the recommended steps fom https://flashrom.org/FAQ :

- The page "https://www.flashrom.org/Supported_hardware" lists ICH7/ICH7R as supported, but this does not seem to be the case for me.

The user manual of the motherboard is available here:
- The manual does also not show any jumpers that protect against bios updates.

- The bios setting "Super BIOS Protect" is disabled.

Do you have any suggestions how to proceed ?