commit | 916cd50edc90bc9edd134d6a37911174cc0ff944 | [log] [tgz] |
---|---|---|
author | Felix Held <felix-coreboot@felixheld.de> | Wed Aug 04 17:22:36 2021 +0200 |
committer | Felix Held <felix-coreboot@felixheld.de> | Wed Sep 08 00:14:17 2021 +0000 |
tree | a3cc30aea20691b290aef50bf29840eeb92e251a | |
parent | 3acf97928ccbbd1f55239f8c890c9acd93170eab [diff] |
soc/amd/*/bootblock,early_fch: rework i2c_scl_pins configuration drive_scl in soc/amd/common/block/i2c/i2c.c writes the raw GPIO MMIO configuration register and drives it as output, so don't initially configure the GPIO as input with no pull up/down. This is a preparation to use the common AMD GPIO access functions instead of the raw register accesses, since the gpio_set function only sets the output value, but doesn't reconfigure the direction. Using gpio_output there instead would reconfigure the direction as well, but would result in doubling the number of MMIO accesses, so just configure the GPIOs correctly right away to avoid that. TEST=The waveform on the SCL pin of I2C3 on a barla/careena Chromebook looks exactly the same as before during the reset_i2c_peripherals call. This was probed at the SCL pad of the unpopulated I2C level shifter on the side that is connected to the SoC. Signed-off-by: Felix Held <felix-coreboot@felixheld.de> Change-Id: I8e94afe0c755a02abcc722d5094e220d8781f8f5 Reviewed-on: https://review.coreboot.org/c/coreboot/+/56807 Reviewed-by: Raul Rangel <rrangel@chromium.org> Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
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.
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.
coreboot supports a wide range of chipsets, devices, and mainboards.
For details please consult:
ANY_TOOLCHAIN
Kconfig option if you're feeling lucky (no support in this case).Optional:
make menuconfig
and make nconfig
)Please consult https://www.coreboot.org/Build_HOWTO for details.
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.
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
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.