linux/drivers/firmware/google/Kconfig, branch master

drm/sysfb: corebootdrm: Add DRM driver for coreboot framebuffers

2026-02-20T13:38:24Z

Add corebootdrm, a DRM driver for coreboot framebuffers. The driver supports a pre-initialized framebuffer with various packed RGB formats. The driver code is fairly small and uses the same logic as the other sysfb drivers. Most of the implementation comes from existing sysfb helpers. Until now, coreboot relied on simpledrm or simplefb for boot-up graphics output. Initialize the platform device for corebootdrm in the same place in framebuffer_probe(). With a later commit, the simple-framebuffer should be removed. v4: - sort include statements (Tzung-Bi) v3: - comment on _HAS_LFB semantics (Tzung-Bi) - fix typo in commit description (Tzung-Bi) - comment on simple-framebuffer being obsolete for coreboot v2: - reimplement as platform driver - limit resources and mappings to known framebuffer memory; no page alignment - create corebootdrm device from coreboot framebuffer code Signed-off-by: Thomas Zimmermann Reviewed-by: Javier Martinez Canillas Acked-by: Julius Werner Acked-by: Tzung-Bi Shih # coreboot Link: https://patch.msgid.link/20260217155836.96267-12-tzimmermann@suse.de

firmware: google: framebuffer: Fix dependencies

2026-02-20T13:38:19Z

The framebuffer on the coreboot bus represents an entry in the coreboot payload table; not the actual device. [1] Hence it must not depend on any other driver setting. Signed-off-by: Thomas Zimmermann Link: https://lore.kernel.org/dri-devel/CAODwPW9_ym3E4za3yoUAs0+1sQfaKTDOau4Oh9Zm8+2uvYVgFQ@mail.gmail.com/ # [1] Acked-by: Tzung-Bi Shih Acked-by: Julius Werner Link: https://patch.msgid.link/20260217155836.96267-6-tzimmermann@suse.de

firmware: coreboot: framebuffer: Allow building with simpledrm

2023-08-04T14:31:32Z

The coreboot framebuffer driver registers a "simple-framebuffer" device based on the information from the firmware, after checking that it's compatible with the formats listed in simplefb.h. It was added before simpledrm, and its Kconfig marked as dependent on the simplefb driver. The simpledrm driver can also handle "simple-framebuffer" devices and the coreboot framebuffer works fine with it on a 'Lick' Chromebook. Allow building the coreboot framebuffer driver with simpledrm as well. Signed-off-by: Alper Nebi Yasak Reviewed-by: Brian Norris Link: https://lore.kernel.org/r/20230725174334.887485-1-alpernebiyasak@gmail.com Signed-off-by: Greg Kroah-Hartman

firmware: coreboot: Remove GOOGLE_COREBOOT_TABLE_ACPI/OF Kconfig entries

2023-02-09T08:24:48Z

Ever since commit a28aad66da8b ("firmware: coreboot: Collapse platform drivers into bus core") the Kconfig entries GOOGLE_COREBOOT_TABLE_OF and GOOGLE_COREBOOT_TABLE_ACPI have been dead. They have no "help" text and thus aren't user choosable. They also aren't "select"ed by anything. They also control the compilation of no code. Let's remove them. Fixes: a28aad66da8b ("firmware: coreboot: Collapse platform drivers into bus core") Signed-off-by: Douglas Anderson Reviewed-by: Guenter Roeck Reviewed-by: Jack Rosenthal Acked-by: Stephen Boyd Link: https://lore.kernel.org/r/20230207081130.1.I657776750156793721efa247ce6293445137bc8a@changeid Signed-off-by: Greg Kroah-Hartman

firmware: google: Implement cbmem in sysfs driver

2022-11-10T17:51:56Z

The CBMEM area is a downward-growing memory region used by coreboot to dynamically allocate tagged data structures ("CBMEM entries") that remain resident during boot. This implements a driver which exports access to the CBMEM entries via sysfs under /sys/bus/coreboot/devices/cbmem-. This implementation is quite versatile. Examples of how it could be used are given below: * Tools like util/cbmem from the coreboot tree could use this driver instead of finding CBMEM in /dev/mem directly. Alternatively, firmware developers debugging an issue may find the sysfs interface more ergonomic than the cbmem tool and choose to use it directly. * The crossystem tool, which exposes verified boot variables, can use this driver to read the vboot work buffer. * Tools which read the BIOS SPI flash (e.g., flashrom) can find the flash layout in CBMEM directly, which is significantly faster than searching the flash directly. Write access is provided to all CBMEM regions via /sys/bus/coreboot/devices/cbmem-/mem, as the existing cbmem tooling updates this memory region, and envisioned use cases with crossystem can benefit from updating memory regions. Link: https://issuetracker.google.com/239604743 Cc: Stephen Boyd Cc: Tzung-Bi Shih Reviewed-by: Guenter Roeck Reviewed-by: Julius Werner Tested-by: Jack Rosenthal Signed-off-by: Jack Rosenthal Link: https://lore.kernel.org/r/20221104161528.531248-1-jrosenth@chromium.org Signed-off-by: Greg Kroah-Hartman

firmware: google: Properly state IOMEM dependency

2022-03-18T13:18:15Z

The Google Coreboot implementation requires IOMEM functions (memmremap, memunmap, devm_memremap), but does not specify this is its Kconfig. This results in build errors when HAS_IOMEM is not set, such as on some UML configurations: /usr/bin/ld: drivers/firmware/google/coreboot_table.o: in function `coreboot_table_probe': coreboot_table.c:(.text+0x311): undefined reference to `memremap' /usr/bin/ld: coreboot_table.c:(.text+0x34e): undefined reference to `memunmap' /usr/bin/ld: drivers/firmware/google/memconsole-coreboot.o: in function `memconsole_probe': memconsole-coreboot.c:(.text+0x12d): undefined reference to `memremap' /usr/bin/ld: memconsole-coreboot.c:(.text+0x17e): undefined reference to `devm_memremap' /usr/bin/ld: memconsole-coreboot.c:(.text+0x191): undefined reference to `memunmap' /usr/bin/ld: drivers/firmware/google/vpd.o: in function `vpd_section_destroy.isra.0': vpd.c:(.text+0x300): undefined reference to `memunmap' /usr/bin/ld: drivers/firmware/google/vpd.o: in function `vpd_section_init': vpd.c:(.text+0x382): undefined reference to `memremap' /usr/bin/ld: vpd.c:(.text+0x459): undefined reference to `memunmap' /usr/bin/ld: drivers/firmware/google/vpd.o: in function `vpd_probe': vpd.c:(.text+0x59d): undefined reference to `memremap' /usr/bin/ld: vpd.c:(.text+0x5d3): undefined reference to `memunmap' collect2: error: ld returned 1 exit status Fixes: a28aad66da8b ("firmware: coreboot: Collapse platform drivers into bus core") Acked-By: anton ivanov Acked-By: Julius Werner Signed-off-by: David Gow Link: https://lore.kernel.org/r/20220225041502.1901806-1-davidgow@google.com Signed-off-by: Greg Kroah-Hartman

firmware: Update Kconfig help text for Google firmware

2021-12-21T09:12:31Z

The help text for GOOGLE_FIRMWARE states that it should only be enabled when building a kernel for Google's own servers. However, many of the drivers dependent on it are also useful on Chromebooks or on any platform using coreboot. Update the help text to reflect this double duty. Fixes: d384d6f43d1e ("firmware: google memconsole: Add coreboot support") Reviewed-by: Julius Werner Signed-off-by: Ben Hutchings Link: https://lore.kernel.org/r/20180618225540.GD14131@decadent.org.uk Signed-off-by: Greg Kroah-Hartman

efi: gsmi: fix false dependency on CONFIG_EFI_VARS

2020-09-29T17:40:57Z

The gsmi code does not actually rely on CONFIG_EFI_VARS, since it only uses the efivars abstraction that is included unconditionally when CONFIG_EFI is defined. CONFIG_EFI_VARS controls the inclusion of the code that exposes the sysfs entries, and which has been deprecated for some time. Signed-off-by: Ard Biesheuvel

treewide: Add SPDX license identifier - Makefile/Kconfig

2019-05-21T08:50:46Z

Add SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any form These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

gsmi: Remove autoselected dependency on EFI and EFI_VARS

2018-10-15T18:32:26Z

Instead of selecting EFI and EFI_VARS automatically when GSMI is enabled let that portion of the driver be conditionally compiled if EFI and EFI_VARS are enabled. This allows the rest of the driver (specifically event log) to be used if EFI_VARS is not enabled. To test: 1) verify that EFI_VARS is not automatically selected when CONFIG_GOOGLE_GSMI is enabled 2) verify that the kernel boots on Link and that GSMI event log is still available and functional 3) specifically boot the kernel on Alex to ensure it does not try to load efivars and that gsmi also does not load because it is not in the supported DMI table Signed-off-by: Duncan Laurie Reviewed-by: Olof Johansson Signed-off-by: Benson Leung Signed-off-by: Ben Zhang Signed-off-by: Filipe Brandenburger Signed-off-by: Furquan Shaikh Tested-by: Furquan Shaikh Reviewed-by: Aaron Durbin [zwisler: update changelog for upstream] Signed-off-by: Ross Zwisler Reviewed-by: Guenter Roeck Signed-off-by: Greg Kroah-Hartman