Assume that an SPI flash chip is represented as /dev/spidev. How do I enable that flash chip's power-cycle write protection?

I want to do some interaction with bios of a embedded linux on an AMD Ryzen embedded platform. The main tool I think is flashrom which can read/write flash chips. It should also be possible to write data to flash rom using something like dd if the address of the chip in memory is known? Is this the correct way to look for system bios: root@device:~/bios# grep ROM /proc/iomem 000c0000-000cd3ff : Video ROM 000f0000-000fffff : System ROM If I look for the rom using flashrom tool I get the following: root@device:~/bios# flashrom -p internal --flash-name flashrom v1.2 on Linux 5.4.199 (x86_64) flashrom is free software, get the source code at https://flashrom.org Using clock_gettime for delay loops (clk_id: 1, resolution: 1ns). Found chipset "AMD FP4". Enabling flash write... OK. Found Winbond flash chip "W25Q64.W" (8192 kB, SPI) mapped at physical address 0x00000000ff800000. vendor="Winbond" name="W25Q64.W" So the iomem says the chip is at 000f0000-000fffff and flashrom is saying he chip is at 0x00000000ff800000 Which one is correct, or better yet, why these are not identical?

Well, I am feeling too old for jumping through several burning hoops to upgrade several firmwares via the usual vendor-specific way: Download some DOS tools, waste some time creating a (Free-)DOS boot medium and wasting more time to make the BIOS actually boot from that and finally flash the firmware upgrade. This is so 1980-ies. I come across some linux flash tool from the Coreboot project . It seems to support various FLASH-chips. But how does it work in practice? I guess there are some pitfalls converting vendor supplied firmware upgrades into the right format. Or what about indentifying the right destination chip? Currently I probably have to upgrade for example: * the firmware of some Seagate 1.5 TB disks * the firmware of an old Abit Athlon 64 board (Award bios) * Bios/Embedded-Controller-Bios of a Thinkpad How do you upgrade your devices firmware at a Linux system?

Hi I need to Reflash the BIOS of my Toshiba Satellite L855-10P using a Linux distro. How can one do this? I have found lots of info on how to read the BIOS (windows & Linux), dump memory from it (Linux), and installation via windows & / usb / floppy but not reflashing in Linux.