Ec build by macpijan · Pull Request #2062 · linuxboot/heads

macpijan · 2026-02-27T14:13:24Z

Snapshot from some experiments. Current issue is building EC firmware in heads build system.

The SDCC version we used for release was: 3.8.0. I could not pin such such version in nix as it was not supported in flakes. Maybe better nix exp this can be done. That would be optimal as it should result with the same hash as the release version.
Bumping SDCC version needs source code changes. Patch included here and pushed to upstream also: 330ebbe
There are more compilation issues with SDCC 4.5 (currently in Debian stable I was trying to build ec-sdk to: update to debian:oldstable-20260223-slim Dasharo/ec-sdk#2

Maybe 4.2.0 would work for both Debian (oldstable) and nix (pin to 4.2.0 should be possible).

Alternative: fetch release EC binary in heads and include it in binary form? Use another build container to build EC?

macpijan · 2026-02-27T14:21:19Z

initrd/etc/functions

+ec_version() {
+	# EC firmware version from DMI type 11 OEM Strings (if present).
+	# The raw sysfs entry has a 5-byte header followed by null-terminated strings.
+	local raw="/sys/firmware/dmi/entries/11-0/raw"


@tlaurion this is completely not tested but gives the idea. If you want EC version submitted in heads setup, you can get this version from DMI table 11. No need for rust EC TOOL.

This is how EC version looks like on my work NV4x laptop from dmidecode:

Handle 0x0009, DMI type 11, 5 bytes OEM Strings String 1: EC: open-source String 2: EC firmware version: 2023-03-10_c0fe220

On V54 it may be a bit different.

merged #2063 so we have EC everywhere from init up to /tmp/debug.log and system info

macpijan · 2026-02-27T14:22:23Z

config/coreboot-novacustom-v540tu.config

 CONFIG_EC_ACPI=y
 CONFIG_EC_DASHARO_EC=y
-# CONFIG_EC_DASHARO_EC_UPDATE is not set
+CONFIG_EC_DASHARO_EC_UPDATE=y


We need this coreboot config switched to support EC SYNC feature.

@mkopec this is the only new config we need to switch here?

yes, that is enough. If the path option is not specified, the code will look for ec.rom in the root of the coreboot directory.

macpijan · 2026-02-27T14:23:27Z

flake.nix

        python3 # me_cleaner, coreboot
        rsync # coreboot
-        sdcc  # Dasharo EC build
+        pkgs-sdcc.sdcc  # Dasharo EC build — pinned to 4.1.0 (4.2+ prototype errors, 4.5 optimizer bug)


SDCC and XXD are the only new tools we need to build EC firmware.

Required to to build dasharo-ec module. Need to pin SDCC version to 4.2.0 to avoid Dasharo/dasharo-issues#1785 and be in sync with ec-sdk: Dasharo/ec-sdk#2 Using 3.8.0 in nix toolchain (as originally used in ec-sdk) was not feasible: linuxboot#2062 (comment) Signed-off-by: Maciej Pijanowski <maciej.pijanowski@3mdeb.com>

macpijan · 2026-02-27T15:13:42Z

Maybe 4.2.0 would work for both Debian (oldstable) and nix (pin to 4.2.0 should be possible).

Using SDCC 4.2.0 results in the same binary hash across heads and ec-sdk builds: 5fbc3b616f50ee84d3b3383b6359e9a759e6b727198866c2fde8f2ffc7da49b6

This differs from the release binary. This has NOT been tested on hardware.

Required to to build dasharo-ec module. Need to pin SDCC version to 4.2.0 to avoid Dasharo/dasharo-issues#1785 and be in sync with ec-sdk: Dasharo/ec-sdk#2 Using 3.8.0 in nix toolchain (as originally used in ec-sdk) was not feasible: linuxboot#2062 (comment) Signed-off-by: Maciej Pijanowski <maciej.pijanowski@3mdeb.com>

initrd/*functions : add logic to show ec version under System Information and recovery shell, populated in init Input for #2062

tlaurion · 2026-02-27T19:23:56Z

@macpijan merged #2063 in master (replaces current f31f198)

tlaurion · 2026-02-27T19:34:41Z

@macpijan docker image v0.2.8 + pinned hash usable from Dasharo#15 (comment), please rebase + cherry-pick + co-sign

tlaurion · 2026-02-27T19:54:44Z

Building locally https://github.com/tlaurion/heads/tree/Dasharo_ec_build_master_merged%2Bcherry_pick to test on v560tu v540tu (master merged+fixed conflicts)

tlaurion · 2026-02-27T20:49:31Z

Building locally https://github.com/tlaurion/heads/tree/Dasharo_ec_build_master_merged%2Bcherry_pick to test on v560tu v540tu (master merged+fixed conflicts)

v540tu EC firmware upgraded to 2026-02-27_ad7e15c

Note that upgrading EC firmware results in fan speeding up to 100%, and a poweroff not a reboot as typically by Heads firmware upgrade

CC @macpijan

tlaurion · 2026-02-27T22:29:35Z

Building locally https://github.com/tlaurion/heads/tree/Dasharo_ec_build_master_merged%2Bcherry_pick to test on v560tu v540tu (master merged+fixed conflicts)

v540tu EC firmware upgraded to 2026-02-27_ad7e15c

Note that upgrading EC firmware results in fan speeding up to 100%, and a poweroff not a reboot as typically by Heads firmware upgrade

CC @macpijan

See comments #2039 (comment)

tlaurion · 2026-03-11T15:46:27Z

@macpijan blocked here because v560tu ec doesn't build. Seperating v540tu/v56tu ec builds should point to different paths in config (not default) and that ec build be local for each coreboot configs.

Good news though, my v540tu gained masive performance gains, battery and proper perf throttle. So it was the EC afterall.

Note that nv4x_adl will need the ec build as well.

Let me know next steps.

tlaurion · 2026-03-11T15:47:29Z

Added proper labels

Squashed from: tlaurion@2df1c8b tlaurion@447d464 then, updated EC revision as per: Dasharo/ec#82 (comment) Signed-off-by: Maciej Pijanowski <maciej.pijanowski@3mdeb.com>

Required to to build dasharo-ec module. Need to pin SDCC version to 4.2.0 to avoid Dasharo/dasharo-issues#1785 and be in sync with ec-sdk: Dasharo/ec-sdk#2 Using 3.8.0 in nix toolchain (as originally used in ec-sdk) was not feasible: linuxboot#2062 (comment) Signed-off-by: Maciej Pijanowski <maciej.pijanowski@3mdeb.com>

macpijan · 2026-03-12T17:22:07Z

I think I rebased and cleaned up my commits. Updated the EC revision so the V56 build can pass here as well.

Copilot

Pull request overview

This PR adds initial support for building and integrating Dasharo EC firmware into the Heads build system for NovaCustom V540TU/V560TU boards, and pins an SDCC toolchain version in Nix to improve build compatibility.

Changes:

Introduces a new dasharo-ec module intended to fetch/build EC firmware and provide ec.rom to coreboot.
Pins a separate nixpkgs revision to provide SDCC 4.2.0 (and adds xxd) in the flake development environment.
Switches NovaCustom V540TU/V560TU coreboot configs from System76 EC to Dasharo EC update integration and enables the module in board configs.

Reviewed changes

Copilot reviewed 6 out of 7 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
modules/dasharo-ec	New module wiring to fetch/build Dasharo EC and stage `ec.rom` for coreboot.
flake.nix	Adds a pinned nixpkgs input to supply SDCC 4.2.0 and includes it in dev dependencies.
flake.lock	Locks the additional nixpkgs input for SDCC pinning.
config/coreboot-novacustom-v560tu.config	Enables Dasharo EC update and sets update file to `ec.rom`.
config/coreboot-novacustom-v540tu.config	Enables Dasharo EC update and sets update file to `ec.rom`.
boards/novacustom-v560tu/novacustom-v560tu.config	Enables `CONFIG_DASHARO_EC` for the board build.
boards/novacustom-v540tu/novacustom-v540tu.config	Enables `CONFIG_DASHARO_EC` for the board build.

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Copilot · 2026-03-12T18:28:50Z

modules/dasharo-ec

+	DASHARO_EC_BOARD_MODEL := v540tu
+else ifeq "$(BOARD)" "novacustom-v560tu"
+	DASHARO_EC_BOARD_MODEL := v560tu
+else
+	$(error "$(BOARD): no Dasharo EC board model mapping defined")


Lines in this conditional use a leading tab before the variable assignment (e.g., DASHARO_EC_BOARD_MODEL := ...). In GNU make, a line starting with a tab outside of a rule body is treated as a recipe line and can trigger "recipe commences before first target" parse errors. Remove the leading tab/indentation on these assignments (use no leading whitespace or spaces).

Suggested change

DASHARO_EC_BOARD_MODEL := v540tu

else ifeq "$(BOARD)" "novacustom-v560tu"

DASHARO_EC_BOARD_MODEL := v560tu

else

$(error "$(BOARD): no Dasharo EC board model mapping defined")

DASHARO_EC_BOARD_MODEL := v540tu

else ifeq "$(BOARD)" "novacustom-v560tu"

DASHARO_EC_BOARD_MODEL := v560tu

else

$(error "$(BOARD): no Dasharo EC board model mapping defined")

Copilot · 2026-03-12T18:28:51Z

modules/dasharo-ec

+# Note: the && chain after make -C runs in the parent cwd, so use
+# absolute paths.  Use sh -c so the shell expands the glob.
+dasharo-ec_target := \
+	BOARD=novacustom/$(DASHARO_EC_BOARD_MODEL) \
+	&& sh -c 'cp $(build)/$(dasharo-ec_dir)/build/novacustom/$(DASHARO_EC_BOARD_MODEL)/*/ec.rom $(build)/$(dasharo-ec_dir)/ec.rom' \
+	&& dd if=/dev/zero of=$(build)/$(dasharo-ec_dir)/ec.rom bs=1 seek=128k count=0 \
+	&& touch $(build)/$(dasharo-ec_dir)/.built
+
+# Copy ec.rom into the coreboot source tree before coreboot configures.
+# coreboot expects ec.rom in its root directory.
+$(build)/$(coreboot_base_dir)/ec.rom: $(build)/$(dasharo-ec_dir)/.build


dasharo-ec_target is passed as arguments to $(MAKE) -C ... $($1_target) by the main build system. Including shell operators like &&, sh -c ..., dd ..., and touch ... here will make make interpret them as additional targets/arguments, which will fail. Move the post-build copy/pad steps into a separate Make rule (e.g., a rule that generates a stable output like ec.rom from $(build)/$(dasharo-ec_dir)/.build), and keep dasharo-ec_target limited to make arguments/targets (e.g., BOARD=...).

Suggested change

# Note: the && chain after make -C runs in the parent cwd, so use

# absolute paths. Use sh -c so the shell expands the glob.

dasharo-ec_target := \

BOARD=novacustom/$(DASHARO_EC_BOARD_MODEL) \

&& sh -c 'cp $(build)/$(dasharo-ec_dir)/build/novacustom/$(DASHARO_EC_BOARD_MODEL)/*/ec.rom $(build)/$(dasharo-ec_dir)/ec.rom' \

&& dd if=/dev/zero of=$(build)/$(dasharo-ec_dir)/ec.rom bs=1 seek=128k count=0 \

&& touch $(build)/$(dasharo-ec_dir)/.built

# Copy ec.rom into the coreboot source tree before coreboot configures.

# coreboot expects ec.rom in its root directory.

$(build)/$(coreboot_base_dir)/ec.rom: $(build)/$(dasharo-ec_dir)/.build

# Note: keep dasharo-ec_target limited to make arguments; post-build

# steps are handled by a dedicated Make rule that produces ec.rom.

dasharo-ec_target := \

BOARD=novacustom/$(DASHARO_EC_BOARD_MODEL)

# Generate a stable ec.rom in the Dasharo EC build directory, pad it to

# 128KB, and update the .built sentinel.

$(build)/$(dasharo-ec_dir)/ec.rom:

sh -c 'cp $(build)/$(dasharo-ec_dir)/build/novacustom/$(DASHARO_EC_BOARD_MODEL)/*/ec.rom $@'

dd if=/dev/zero of=$@ bs=1 seek=128k count=0

touch $(build)/$(dasharo-ec_dir)/.built

# Copy ec.rom into the coreboot source tree before coreboot configures.

# coreboot expects ec.rom in its root directory.

$(build)/$(coreboot_base_dir)/ec.rom: $(build)/$(dasharo-ec_dir)/ec.rom

Copilot · 2026-03-12T18:28:51Z

modules/dasharo-ec

+# Use .built sentinel since the real output is in a dynamic path
+dasharo-ec_output := .built
+


dasharo-ec_output is set to .built, but the generic module framework only guarantees creation of $(build)/$(dasharo-ec_dir)/.build (it touches that file after running make). Unless .built is created as part of the module's make invocation, the build will be forced every time and any downstream rules expecting ec.rom may fail. Define the module output as an actual produced artifact (e.g., ec.rom) and add an explicit rule to create it, or ensure .built is created by the invoked make target.

Copilot · 2026-03-12T18:28:51Z

modules/dasharo-ec

+
+# Copy ec.rom into the coreboot source tree before coreboot configures.
+# coreboot expects ec.rom in its root directory.
+$(build)/$(coreboot_base_dir)/ec.rom: $(build)/$(dasharo-ec_dir)/.build


This rule copies $(build)/$(dasharo-ec_dir)/ec.rom but only depends on $(build)/$(dasharo-ec_dir)/.build. With the current module definition, .build does not guarantee that ec.rom exists at that stable path. Make the prerequisite the actual artifact you intend to copy (e.g., depend on $(build)/$(dasharo-ec_dir)/ec.rom once it is generated as the module output) so the dependency graph reflects the real inputs/outputs.

Suggested change

$(build)/$(coreboot_base_dir)/ec.rom: $(build)/$(dasharo-ec_dir)/.build

$(build)/$(coreboot_base_dir)/ec.rom: $(build)/$(dasharo-ec_dir)/ec.rom

tlaurion · 2026-03-12T19:26:28Z

@macpijan docker image v0.2.8 + pinned hash usable from Dasharo#15 (comment), please rebase + cherry-pick + co-sign

Regression to prior 2.7 docker image.

ec.rom still shared between builds, won't fly :(

Coreboot configs need to point in distinguished paths for ec for all boards, and dasharo-ec do the right thing placing it where expected.

CC @macpijan

tlaurion · 2026-03-12T19:27:28Z

I think I rebased and cleaned up my commits. Updated the EC revision so the V56 build can pass here as well.

@macpijan do you need me to change anything that was added to docker image 2.8 pinned by hash? Not sure I follow.

macpijan commented Feb 27, 2026

View reviewed changes

macpijan mentioned this pull request Feb 27, 2026

REGRESSION TESTING for next Dasharo+Heads: v560tu/v540tu dasharo tag 1.0.1 / nv4x_adl 1.8.0-rc4 (ns50 partial, todo: remove changes) #2039

Draft

macpijan force-pushed the ec_build branch from 7122c38 to ba78e86 Compare February 27, 2026 15:12

macpijan force-pushed the ec_build branch from ba78e86 to 0a8ed7b Compare February 27, 2026 15:22

macpijan force-pushed the ec_build branch from 0a8ed7b to f31f198 Compare February 27, 2026 18:16

tlaurion added a commit that referenced this pull request Feb 27, 2026

Merge pull request #2063 from tlaurion/show_ec_version

5d20cb3

initrd/*functions : add logic to show ec version under System Information and recovery shell, populated in init Input for #2062

tlaurion mentioned this pull request Feb 27, 2026

Ec build nix docker changes Dasharo/heads#15

Open

tlaurion mentioned this pull request Mar 5, 2026

v560tu/v540tu seems slow on IO, needs confirmation #1894

Closed

tlaurion added feature freeze 2026-04 enhancement bug buildsystem documentation Power Management upstream labels Mar 11, 2026

macpijan added 2 commits March 12, 2026 18:10

modules/dasharo-ec: new module

fe3d278

Squashed from: tlaurion@2df1c8b tlaurion@447d464 then, updated EC revision as per: Dasharo/ec#82 (comment) Signed-off-by: Maciej Pijanowski <maciej.pijanowski@3mdeb.com>

macpijan force-pushed the ec_build branch from f31f198 to f263fa2 Compare March 12, 2026 17:19

tlaurion requested a review from Copilot March 12, 2026 18:21

Copilot started reviewing on behalf of tlaurion March 12, 2026 18:22 View session

Copilot AI reviewed Mar 12, 2026

View reviewed changes

		# Use .built sentinel since the real output is in a dynamic path
		dasharo-ec_output := .built

	$(build)/$(coreboot_base_dir)/ec.rom: $(build)/$(dasharo-ec_dir)/.build
	$(build)/$(coreboot_base_dir)/ec.rom: $(build)/$(dasharo-ec_dir)/ec.rom

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