| commit | 3ba6f8cdf8d95607c8efd8f6d18a9fffc9983e1e | [log] [tgz] |
|---|---|---|
| author | Subrata Banik <subratabanik@google.com> | Wed Mar 23 03:22:28 2022 +0530 |
| committer | Felix Held <felix-coreboot@felixheld.de> | Fri Mar 25 20:10:09 2022 +0000 |
| tree | 3f7c43f651b4aafedcaeff66d12ec78824b2a7c8 | |
| parent | bbf5de55caebd6814db129e484aeb158fc7eafd5 [diff] |
drivers/intel/fsp2_0: Add native implementation for FSP Debug Handler This patch implements coreboot native debug handler to manage the FSP event messages. `FSP Event Handlers` feature introduced in FSP to generate event messages to aid in the debugging of firmware issues. This eliminates the need for FSP to directly write debug messages to the UART and FSP might not need to know the board related UART port configuration. Instead FSP signals the bootloader to inform it of a new debug message. This allows the coreboot to provide board specific methods of reporting debug messages, example: legacy UART or LPSS UART etc. This implementation has several advantages as: 1. FSP relies on XIP `DebugLib` driver even while printing FSP-S debug messages, hence, without ROM being cached, post `romstage` would results into sluggish boot with FSP debug enabled. This patch utilities coreboot native debug implementation which is XIP during FSP-M and relocatable to DRAM based resource for FSP-S. 2. This patch simplifies the FSP DebugLib implementation and remove the need to have serial port library. Instead coreboot `printk` can be used for display FSP serial messages. Additionally, unifies the debug library between coreboot and FSP. 3. This patch is also useful to get debug prints even with FSP non-serial image (refer to `Note` below) as FSP PEIMs are now leveraging coreboot debug library instead FSP `NULL` DebugLib reference for release build. 4. Can optimize the FSP binary size by removing the DebugLib dependency from most of FSP PEIMs, for example: on Alder Lake FSP-M debug binary size is reduced by ~100KB+ and FSP-S debug library size is also reduced by ~300KB+ (FSP-S debug and release binary size is exactly same with this code changes). The total savings is ~400KB for each FSP copy, and in case of Chrome AP firmware with 3 copies, the total savings would be 400KB * 3 = ~1.2MB. Note: Need to modify FSP source code to remove `MDEPKG_NDEBUG` as compilation flag for release build and generate FSP binary with non-NULL FSP debug wrapper module injected (to allow FSP event handler to execute even with FSP non-serial image) in the final FSP.fd. BUG=b:225544587 TEST=Able to build and boot brya. Also, verified the FSP debug log is exactly same before and with this code change. Signed-off-by: Subrata Banik <subratabanik@google.com> Change-Id: I1018e67d70492b18c76531f9e78d3b58fa435cd4 Reviewed-on: https://review.coreboot.org/c/coreboot/+/63007 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
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.