kernel/linux.git/drivers/firmware/google/framebuffer-coreboot.c, branch v7.1-rc5

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

2026-02-20T13:38:24+00:00

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: Export coreboot table entries

2026-02-20T13:38:21+00:00

Move types for coreboot table entries to . Allows drivers in other subsystems to use these structures. Signed-off-by: Thomas Zimmermann Acked-by: Tzung-Bi Shih Acked-by: Julius Werner Link: https://patch.msgid.link/20260217155836.96267-9-tzimmermann@suse.de

firmware: google: Clean up include statements in coreboot_table.h

2026-02-20T13:38:20+00:00

Include from source files and only forward- declare struct coreboot_device_id in coreboot_table.h. Signed-off-by: Thomas Zimmermann Reviewed-by: Javier Martinez Canillas Acked-by: Tzung-Bi Shih Acked-by: Julius Werner Link: https://patch.msgid.link/20260217155836.96267-8-tzimmermann@suse.de

firmware: google: framebuffer: Tie platform device to PCI hardware

2026-02-20T13:38:19+00:00

Use the PCI device as parent of the system-framebuffer device instead of the coreboot device. Prevents SIGBUS or SIGSEG after hot-unplug of the PCI device while the framebuffer is active. The simple-framebuffer device depends on the PCI hardware, so this device needs to be its parent. The current coreboot parent is no longer needed after the system-framebuffer device has been created. On systems without PCI or if no PCI parent device could be found, the platform device hangs on the platform bus directly. The fix here is similar to code in sysfb, which contained that same bug. Signed-off-by: Thomas Zimmermann Acked-by: Tzung-Bi Shih Acked-by: Julius Werner Link: https://patch.msgid.link/20260217155836.96267-5-tzimmermann@suse.de

firmware: google: framebuffer: Init memory resource with helper macro

2026-02-20T13:38:18+00:00

Initialize framebuffer memory resource with DEFINE_RES_MEM() instead of open-coding the setup. While at it, drop the resource name to make the kernel use the device name of the simple-framebuffer device for the resource. The latter includes a device number. While the meaning of the resource name is somewhat fuzzy and varies across entries in /proc/iomem, showing the device name seems more helpful than showing a fixed name. Signed-off-by: Thomas Zimmermann Acked-by: Tzung-Bi Shih Acked-by: Julius Werner Link: https://patch.msgid.link/20260217155836.96267-4-tzimmermann@suse.de

firmware: google: framebuffer: Do not mark framebuffer as busy

2026-02-20T13:38:18+00:00

Remove the flag IORESOURCE_BUSY flag from coreboot's framebuffer resource. It prevents simpledrm from successfully requesting the range for its own use; resulting in errors such as [ 2.775430] simple-framebuffer simple-framebuffer.0: [drm] could not acquire memory region [mem 0x80000000-0x80407fff flags 0x80000200] As with other uses of simple-framebuffer, the simple-framebuffer device should only declare it's I/O resources, but not actively use them. Signed-off-by: Thomas Zimmermann Fixes: 851b4c14532d ("firmware: coreboot: Add coreboot framebuffer driver") Acked-by: Tzung-Bi Shih Acked-by: Julius Werner Cc: Samuel Holland Cc: Greg Kroah-Hartman Cc: Tzung-Bi Shih Cc: Brian Norris Cc: Julius Werner Cc: chrome-platform@lists.linux.dev Cc: # v4.18+ Link: https://patch.msgid.link/20260217155836.96267-3-tzimmermann@suse.de

firmware: google: framebuffer: Do not unregister platform device

2026-02-20T13:38:17+00:00

The native driver takes over the framebuffer aperture by removing the system- framebuffer platform device. Afterwards the pointer in drvdata is dangling. Remove the entire logic around drvdata and let the kernel's aperture helpers handle this. The platform device depends on the native hardware device instead of the coreboot device anyway. When commit 851b4c14532d ("firmware: coreboot: Add coreboot framebuffer driver") added the coreboot framebuffer code, the kernel did not support device-based aperture management. Instead native driviers only removed the conflicting fbdev device. At that point, unregistering the framebuffer device most likely worked correctly. It was definitely broken after commit d9702b2a2171 ("fbdev/simplefb: Do not use struct fb_info.apertures"). So take this commit for the Fixes tag. Earlier releases might work depending on the native hardware driver. Signed-off-by: Thomas Zimmermann Fixes: d9702b2a2171 ("fbdev/simplefb: Do not use struct fb_info.apertures") Acked-by: Tzung-Bi Shih Acked-by: Julius Werner Cc: Thomas Zimmermann Cc: Javier Martinez Canillas Cc: Hans de Goede Cc: linux-fbdev@vger.kernel.org Cc: # v6.3+ Link: https://patch.msgid.link/20260217155836.96267-2-tzimmermann@suse.de

firmware: coreboot: Don't register a pdev if screen_info data is present

2024-09-30T01:40:51+00:00

On coreboot platforms, a system framebuffer may be provided to the Linux kernel by filling a LB_TAG_FRAMEBUFFER entry in the coreboot table. But a coreboot payload (e.g: SeaBIOS) could also provide its own framebuffer information to the Linux kernel. If that's the case, arch x86 boot code will fill the global screen_info data and this used by the Generic System Framebuffers (sysfb) framework, to register a platform device with pdata about the system's framebuffer. But later, the framebuffer_coreboot driver will try to do the same and attempt to register a "simple-framebuffer" platform device (using the information from the coreboot table), which will lead to an error due a device with the same name already being registered: sysfs: cannot create duplicate filename '/bus/platform/devices/simple-framebuffer.0' ... coreboot: could not register framebuffer framebuffer coreboot8: probe with driver framebuffer failed with error -17 To prevent this issue, make the framebuffer_core driver to not register a platform device if the global struct screen_info data has been filled. Reported-by: Brian Norris Closes: https://lore.kernel.org/all/ZuCG-DggNThuF4pj@b20ea791c01f/T/#ma7fb65acbc1a56042258adac910992bb225a20d2 Suggested-by: Julius Werner Signed-off-by: Javier Martinez Canillas Reviewed-by: Thomas Zimmermann Reviewed-by: Brian Norris Reviewed-by: Julius Werner Link: https://lore.kernel.org/r/20240916110040.1688511-3-javierm@redhat.com Signed-off-by: Tzung-Bi Shih

firmware: google: add missing MODULE_DESCRIPTION() macros

2024-06-11T03:34:05+00:00

make allmodconfig && make W=1 C=1 reports: WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/firmware/google/gsmi.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/firmware/google/coreboot_table.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/firmware/google/framebuffer-coreboot.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/firmware/google/memconsole.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/firmware/google/memconsole-coreboot.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/firmware/google/memconsole-x86-legacy.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/firmware/google/cbmem.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/firmware/google/vpd-sysfs.o Add the missing invocations of the MODULE_DESCRIPTION() macro. Signed-off-by: Jeff Johnson Link: https://lore.kernel.org/r/20240605-md-drivers-firmware-google-v1-1-18878de97fa5@quicinc.com Signed-off-by: Tzung-Bi Shih

firmware: coreboot: Replace tag with id table in driver struct

2024-02-17T00:53:06+00:00

Switch the plain 'tag' field in struct coreboot_driver for the newly created coreboot_device_id struct, which also contains a tag field and has the benefit of allowing modalias generation, and update all coreboot drivers accordingly. While at it, also add the id table for each driver to the module device table to allow automatically loading the module. Reviewed-by: AngeloGioacchino Del Regno Reviewed-by: Brian Norris Signed-off-by: Nícolas F. R. A. Prado Link: https://lore.kernel.org/r/20240212-coreboot-mod-defconfig-v4-3-d14172676f6d@collabora.com Signed-off-by: Tzung-Bi Shih