linux/drivers/firmware/google/Kconfig

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# SPDX-License-Identifier: GPL-2.0-only
menuconfig GOOGLE_FIRMWARE
bool "Google Firmware Drivers"
default n
help
These firmware drivers are used by Google servers,
Chromebooks and other devices using coreboot firmware.
If in doubt, say "N".
if GOOGLE_FIRMWARE
config GOOGLE_SMI
tristate "SMI interface for Google platforms"
depends on X86 && ACPI && DMI
help
Say Y here if you want to enable SMI callbacks for Google
platforms. This provides an interface for writing to and
clearing the event log. If CONFIG_EFI is also enabled this
driver provides an interface for reading and writing NVRAM
variables.
firmware: google: Implement cbmem in sysfs driver 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-<id>. 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-<id>/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 <swboyd@chromium.org> Cc: Tzung-Bi Shih <tzungbi@kernel.org> Reviewed-by: Guenter Roeck <groeck@chromium.org> Reviewed-by: Julius Werner <jwerner@chromium.org> Tested-by: Jack Rosenthal <jrosenth@chromium.org> Signed-off-by: Jack Rosenthal <jrosenth@chromium.org> Link: https://lore.kernel.org/r/20221104161528.531248-1-jrosenth@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-05 00:15:28 +08:00
config GOOGLE_CBMEM
tristate "CBMEM entries in sysfs"
depends on GOOGLE_COREBOOT_TABLE
help
CBMEM is a downwards-growing memory region created by the
Coreboot BIOS containing tagged data structures from the
BIOS. These data structures expose things like the verified
boot firmware variables, flash layout, firmware event log,
and more.
This option enables the cbmem module, which causes the
kernel to search for Coreboot CBMEM entries, and expose the
memory for each entry in sysfs under
/sys/bus/coreboot/devices/cbmem-<id>.
config GOOGLE_COREBOOT_TABLE
tristate "Coreboot Table Access"
firmware: google: Properly state IOMEM dependency 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 <anton.ivanov@cambridgegreys.com> Acked-By: Julius Werner <jwerner@chromium.org> Signed-off-by: David Gow <davidgow@google.com> Link: https://lore.kernel.org/r/20220225041502.1901806-1-davidgow@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-25 12:15:02 +08:00
depends on HAS_IOMEM && (ACPI || OF)
help
This option enables the coreboot_table module, which provides other
firmware modules access to the coreboot table. The coreboot table
pointer is accessed through the ACPI "GOOGCB00" object or the
device tree node /firmware/coreboot.
If unsure say N.
config GOOGLE_MEMCONSOLE
tristate
depends on GOOGLE_MEMCONSOLE_X86_LEGACY || GOOGLE_MEMCONSOLE_COREBOOT
config GOOGLE_MEMCONSOLE_X86_LEGACY
tristate "Firmware Memory Console - X86 Legacy support"
depends on X86 && ACPI && DMI
select GOOGLE_MEMCONSOLE
help
This option enables the kernel to search for a firmware log in
the EBDA on Google servers. If found, this log is exported to
userland in the file /sys/firmware/log.
config GOOGLE_FRAMEBUFFER_COREBOOT
tristate "Coreboot Framebuffer"
depends on FB_SIMPLE || DRM_SIMPLEDRM
depends on GOOGLE_COREBOOT_TABLE
help
This option enables the kernel to search for a framebuffer in
the coreboot table. If found, it is registered with simplefb.
config GOOGLE_MEMCONSOLE_COREBOOT
tristate "Firmware Memory Console"
depends on GOOGLE_COREBOOT_TABLE
select GOOGLE_MEMCONSOLE
help
This option enables the kernel to search for a firmware log in
the coreboot table. If found, this log is exported to userland
in the file /sys/firmware/log.
config GOOGLE_VPD
tristate "Vital Product Data"
depends on GOOGLE_COREBOOT_TABLE
help
This option enables the kernel to expose the content of Google VPD
under /sys/firmware/vpd.
endif # GOOGLE_FIRMWARE