From 592a4b5fd336f57168c08eff357caf74ccec696f Mon Sep 17 00:00:00 2001 From: Martin Kepplinger Date: Fri, 19 Jan 2018 16:36:11 +0100 Subject: [PATCH] README: Explain why this works and what is optional --- README.md | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/README.md b/README.md index 9b9b5a0..aa36eb9 100644 --- a/README.md +++ b/README.md @@ -40,14 +40,14 @@ Download a released image, connect your hardware SPI flasher to the "upper" ## Flashing for the first time -### EC firmware +### EC firmware (optional) Enter Lenovo's BIOS with __F1__ and check the embedded controller (EC) version to be __1.14__ and upgrade using [the latest bootable CD](https://support.lenovo.com/at/en/downloads/ds029188) if it isn't. The EC cannot be upgraded when coreboot is installed. (In case a newer version should ever be available (I doubt it), you could temporarily flash back your original Lenovo BIOS image) -### me_cleaner +### me_cleaner (optional) The Intel Management Engine resides on the 8MB chip. We don't need to touch it for coreboot-upgrades in the future, but while opening up the Thinkpad anyways, we can save it and run [ifdtool](https://github.com/coreboot/coreboot/tree/master/util/ifdtool) @@ -67,7 +67,7 @@ and [me_cleaner](https://github.com/corna/me_cleaner) on it: part, but we can essientially ignore that) For the first time, we have to save the original image, just like we did with -the 8MB chip above: +the 8MB chip. It's important to keep this image somewhere safe: flashrom -p linux_spi:dev=/dev/spidev0.0,spispeed=128 -r top1.rom @@ -141,3 +141,10 @@ coreboot is not hard at all. Please refer to [coreboot's own documentation](http When building, testing and doing a release here, we always try to upload our result to coreboot's [board status project](https://www.coreboot.org/Supported_Motherboards). + +## Why does this work? +On the X230, there are 2 physical "BIOS" chips. The "upper" 4MB +one holds the actual bios we can generate using coreboot, and the "lower" 8MB +one holds the rest that you can [modify yourself once](#flashing-for-the-first-time), +if you like, but strictly speaking, you don't need to touch it at all. What's this "rest"? +Mainly a tiny binary used by the Ethernet card and the Intel Management Engine.