commit | d6727ba9723be806713320a7ff19e5d5c3bd1d3f | [log] [tgz] |
---|---|---|
author | Rex-BC Chen <rex-bc.chen@mediatek.com> | Wed Mar 16 11:13:27 2022 +0800 |
committer | Hung-Te Lin <hungte@chromium.org> | Mon Mar 21 03:11:44 2022 +0000 |
tree | 4b3ace106c4c88302dc849358e4c58e88e4bfca8 | |
parent | 5b51faaaea48adf49429d4bfb96d88d9e5d9e08c [diff] |
mb/google/corsola: Revise power-on sequence of PS8640 Although the panel initializes fine and the fw recovery screen is displayed without issues, the current power-on sequence of the PS8640 violates the spec of the PS8640, which can be confirmed by measuring it with an oscilloscope. The sequence is: - set VDD12 to be 1.2V - set VDD33 to be 3.3V - pull hign PD# - pull down RST# - delay 2ms - pull high RST# - delay more than 50ms (55ms for margin) - pull down RST# - delay more than 50ms (55ms for margin) - pull high RST# This flow will increase 110ms if firmware display is enabled in krabby. For normal booting flow, the firmware will not be enabled, so it will meet boot time requirements of Chrome OS. (Less than 1s.) Datasheet name: PS8640_DS_V1.4_20200210.docx. Chapter: 14. BUG=b:222650141 TEST=show fw display normally in krabby. TEST=result of waveform meets the spec. Signed-off-by: Rex-BC Chen <rex-bc.chen@mediatek.com> Change-Id: I7706c56dc7fc13ac84c0d52a6e534bc0988e8fd3 Reviewed-on: https://review.coreboot.org/c/coreboot/+/62893 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Paul Menzel <paulepanter@mailbox.org> Reviewed-by: Yu-Ping Wu <yupingso@google.com>
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.