install/w541_external: new guide

based off of t440p_external

it tells how to flash libreboot on the w541

Signed-off-by: Leah Rowe <info@minifree.org>

site/docs/install/index.md

@@ -304,7 +304,7 @@ If you are re-flashing a GM45+ICH9M laptop (e.g. ThinkPad X200/X200S/X200T,
 T400, T500, R400, W500 etc - but not R500), you should run the ich9gen utility
 to preserve your mac address.
 Please read the ich9utils documentation:
-[/docs/install/ich9utils.html](/docs/install/ich9utils.html)
+[ich9utils.md](ich9utils.md)
 
 NOTE: `force_I_want_a_brick` is not scary. Do not be scared! This merely disables
 the safety checks in flashprog. Flashrom and coreboot change a lot, over the years,
@@ -390,7 +390,7 @@ reference this paragraph on this web page.
 
 Ignore this section. Internal flashing *is* possible, but there are two chips
 and you must flash both chips. Refer to the guide:\
-[Gigabyte GA-G41M-ES2L installation guide](ga-g41m-es2l.html)
+[Gigabyte GA-G41M-ES2L installation guide](ga-g41m-es2l.md)
 
 #### Macbook1,1 running original Apple EFI firmware
 
@@ -865,7 +865,7 @@ Refer to the [ivybridge/haswell common guide.](ivy_has_common.md) for how to
 make the rom image usable for external flashing (with a clip). **If using
 release ROMs, you must insert the neutered ME. Look at the info on that page.**
 
-Read [board documentation](/docs/install/x230_external.html) for disassembly.
+Read [board documentation](x230_external.md) for disassembly.
 
 TARGET: Thinkpad X230t
 ---------------------
@@ -876,7 +876,7 @@ LIBREBOOT](../../news/safety.md).**
 Refer to the [ivybridge/haswell common guide.](ivy_has_common.md) for how to
 make the rom image usable for external flashing.
 
-Read [board documentation](/docs/install/x230_external.html) for disassembly.
+Read [board documentation](x230_external.md) for disassembly.
 (same instructions as X230, for this purpose of external flashing, but
 full disassembly will differ slightly)
 
@@ -892,7 +892,9 @@ LIBREBOOT](../../news/safety.md).**
 Refer to the [ivybridge/haswell common guide.](ivy_has_common.md) for how to
 make the rom image usable for external flashing.
 
-Read [board documentation](/docs/install/t440p_external.html) for disassembly.
+T440p: Read [board documentation](t440p_external.md) for disassembly.
+
+W541: Read [board documentation](w541_external.md)
 
 **If using release ROMs, neutered ME must be inserted. Refer to the above
 guide.**

site/docs/install/w541_external.md

@@ -0,0 +1,137 @@
+---
+title: ThinkPad W541/W540 external flashing
+x-toc-enable: true
+...
+
+NOTE: The same image for W541 also works on W541, as it's the exact same
+mainboard.
+
+Buy Libreboot preinstalled
+==========================
+
+This laptop is available to buy with Libreboot pre-installed:
+<https://minifree.org/product/libreboot-w541/>
+
+Introduction
+============
+
+NOTE: Libreboot standardises on [flashprog](https://flashprog.org/wiki/Flashprog)
+now, as of 27 January 2024, which is a fork of flashrom.
+
+**[PLEASE READ THESE INSTRUCTIONS BEFORE INSTALLING](../../news/safety.md),
+OR YOU MIGHT BRICK YOUR MACHINE: [SAFETY PRECAUTIONS](../../news/safety.md)**
+
+Read the [Ivybridge/Haswell common guide](/docs/install/ivy_has_common.html) if you want more information.
+All of the following instructions assume that you've cloned lbmk and are operating from the
+root of that project. To do so, run
+
+	git clone https://codeberg.org/libreboot/lbmk
+	cd lbmk
+
+You can now follow the rest of the instructions.
+
+Preparing a release Rom
+-----------------------
+
+You must patch the release rom with the necessary vendor files *and then* flash it to your board.
+
+Lbmk includes a script that will automatically inject the necessary files into a rom file.
+The script can determine the board automatically if you have not changed the name, but you can also manually set the board name with the `-b` flag.
+
+In order to inject the necessary files into a rom image, run the script from the root of lbmk and point to the rom image.
+
+If you only wish to flash a release rom then the process of injecting the necessary files is quite simple.
+Run the injection script pointing to the release archive you downloaded:
+
+	./vendor inject /path/to/libreboot-RELEASE_targetname.tar.xz
+
+The script can automatically detect the board as long as you do not change the file name.
+You can then find flash-ready ROMs in `/bin/release/`
+
+Alternatively, you may patch only a single rom file.
+For example:
+
+	./vendor inject -r w541_libreboot.rom -b w541_12mb
+
+Optionally, you can use this script to modify the mac address of the rom with the `-m` flag.
+For example:
+
+	./vendor inject -r w541_libreboot.rom -b w541_12mb -m 00:f6:f0:40:71:fd
+
+NOTE: this makes use of `nvmutil`, which you can read more about in
+the [nvmutil documentation](nvmutil.md).
+
+Splitting The Rom
+-----------------
+
+You can use `dd` to easily split your rom into the two separate portions for
+external flashing.
+
+	dd if=libreboot.rom of=top.rom bs=1M skip=8
+	dd if=libreboot.rom of=bottom.rom bs=1M count=8
+
+Flash the top chip with top.rom, and tho bottom chip with bottom.rom.
+Don't worry about knowing which chip is which on a standard setup; flashprog will let you know if the 
+image size is incorrect for the chip you're flashing.
+
+
+Disassembly
+-----------
+
+No disassembly pics yet. The W540/T540p hardware maintenance manual also
+applies to W541:
+
+<https://thinkpads.com/support/hmm/hmm_pdf/t540p_w540_hmm_en_sp40a26003_01.pdf>
+
+This shows disassembly. When you disassemble, and get to flashing, please note:
+
+MOSI/MISO lines are linked between the two flash ICs, at zero ohms. This is OK
+for internal flashing and normal operation, because the PCH turns each chip on
+or off as needed, by controlling each IC's own *chip select* pin, which is
+pin 1.
+
+When you wire the clip, to flash one of the ICs, the same voltage rail also
+turns on the other IC and the other IC's own chip-select is in a *floating*
+state, which in practise means *high logic state*; in other words, the other
+flash will be active.
+
+This means that external flashing would not ordinarily work, unless you use
+the following trick:
+
+Use a *test hook* wired to VCC (+3.3v), to pull the other flash's chip-select
+high. So: when flashing one of the two ICs, the other chip must have pin 1
+connected to VCC. You can do this with the same 3.3v power source that you use
+on pin 8 of the chip that you're flashing. Ideally you should pull the other
+chip select high via 47ohm resistor, which should be enough to prevent damage
+in the case of accidentally shorting the wrong pin.
+
+If you do it right, the chips should flash reliably. This same trick must be
+used when flashing either of the chips.
+
+You can now proceed to [flashing](/docs/install/spi.html) this machine.
+
+Errata
+======
+
+NOTE: As of Libreboot releases from May 2024 onward, the Intel MRC is no longer
+included for Haswell; MRC is a blob for raminit, but we now provide libre
+raminit. The following targets no longer exist in the build system:
+
+* `t440pmrc_12mb` (use `t440plibremrc_12mb` instead)
+* `t440pbmrc_12mb` (use `t440plibremrc_12mb` instead)
+* `w541mrc_12mb` (use `w541_12mb` instead)
+* `w541bmrc_12mb` (use `w541_12mb` instead)
+* `dell9020sff_12mb` (use `dell9020sff_nri_12mb` instead)
+* `dell9020sffbmrc` (use `dell9020sff_nri_12mb` instead)
+* `dell9020mt_12mb` (use `dell9020mt_nri_12mb` instead)
+* `dell9020mtbmrc` (use `dell9020mt_nri_12mb` instead)
+
+This is written as errata because some users may still be using older release
+images but on the newer build system from May 2024 onward; you must use the
+Libreboot 20240225 release if you want to inject MRC and so on, for these older
+targets.
+
+Libreboot's [binary blob reduction policy](../../news/policy.md) is very strict,
+and states: if a blob can be avoided, it must be avoided. Therefore, the MRC
+is removed on Haswell and Libreboot will only use the libre raminit (called
+NRI, short for Native Ram Initialisation).