b82afce18a
FT4 has a strange property where whenever the debounce registers for any one gpio are changed, the FT4 disables interrupt propagation for ALL gpio irqs for ~4ms. In other words, if an edge interrupt of one gpio happens exactly during this debounce-irq-off window immediately following the configuration of another gpio, the interrupt will be lost. It is quite difficult to deal with this in the kernel, since during kernel boot time, drivers & devices are probed asynchronously, meaning it may happen that an already loaded driver may miss an interrupt when some later driver is being probed and configuring its gpio interrupt. To eliminate this possibility, we pre-configure the debounce registers in ram stage for all gpios that will be used as irqs later by the kernel using the same configuration as used by the kernel, as per this table: IRQ Debounce Edge Remove Glitch Level High Preserve Low Glitch Level Low Preserve High Glitch Signed-off-by: Daniel Kurtz <djkurtz@chromium.org> BUG=b:113880780 BRANCH=none TEST=Reboot stress test grunt (>100 times); no messages in dmesg like: tpm tpm0: Timeout waiting for TPM ready Change-Id: I94c7ecfb14e5bb209b3598e10287c80eb19da25b Reviewed-on: https://review.coreboot.org/c/30921 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Martin Roth <martinroth@google.com> |
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|---|---|---|
| 3rdparty | ||
| Documentation | ||
| configs | ||
| payloads | ||
| src | ||
| util | ||
| .checkpatch.conf | ||
| .clang-format | ||
| .gitignore | ||
| .gitmodules | ||
| .gitreview | ||
| COPYING | ||
| MAINTAINERS | ||
| Makefile | ||
| Makefile.inc | ||
| README.md | ||
| gnat.adc | ||
| toolchain.inc | ||
README.md
coreboot README
coreboot is a Free Software project aimed at replacing the proprietary BIOS (firmware) found in most computers. coreboot performs a little bit of hardware initialization and then executes additional boot logic, called a payload.
With the separation of hardware initialization and later boot logic, coreboot can scale from specialized applications that run directly firmware, run operating systems in flash, load custom bootloaders, or implement firmware standards, like PC BIOS services or UEFI. This allows for systems to only include the features necessary in the target application, reducing the amount of code and flash space required.
coreboot was formerly known as LinuxBIOS.
Payloads
After the basic initialization of the hardware has been performed, any desired "payload" can be started by coreboot.
See https://www.coreboot.org/Payloads for a list of supported payloads.
Supported Hardware
coreboot supports a wide range of chipsets, devices, and mainboards.
For details please consult:
- https://www.coreboot.org/Supported_Motherboards
- https://www.coreboot.org/Supported_Chipsets_and_Devices
Build Requirements
- make
- gcc / g++
Because Linux distribution compilers tend to use lots of patches. coreboot
does lots of "unusual" things in its build system, some of which break due
to those patches, sometimes by gcc aborting, sometimes - and that's worse -
by generating broken object code.
Two options: use our toolchain (eg. make crosstools-i386) or enable the
ANY_TOOLCHAINKconfig option if you're feeling lucky (no support in this case). - iasl (for targets with ACPI support)
- pkg-config
- libssl-dev (openssl)
Optional:
- doxygen (for generating/viewing documentation)
- gdb (for better debugging facilities on some targets)
- ncurses (for
make menuconfigandmake nconfig) - flex and bison (for regenerating parsers)
Building coreboot
Please consult https://www.coreboot.org/Build_HOWTO for details.
Testing coreboot Without Modifying Your Hardware
If you want to test coreboot without any risks before you really decide to use it on your hardware, you can use the QEMU system emulator to run coreboot virtually in QEMU.
Please see https://www.coreboot.org/QEMU for details.
Website and Mailing List
Further details on the project, a FAQ, many HOWTOs, news, development guidelines and more can be found on the coreboot website:
You can contact us directly on the coreboot mailing list:
https://www.coreboot.org/Mailinglist
Copyright and License
The copyright on coreboot is owned by quite a large number of individual developers and companies. Please check the individual source files for details.
coreboot is licensed under the terms of the GNU General Public License (GPL). Some files are licensed under the "GPL (version 2, or any later version)", and some files are licensed under the "GPL, version 2". For some parts, which were derived from other projects, other (GPL-compatible) licenses may apply. Please check the individual source files for details.
This makes the resulting coreboot images licensed under the GPL, version 2.