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cee8532ce3
The pch_smbus_init() function contains code to enable clock gating for the SMBus controller. Unfortunately this code is buggy and leads to a hanging system with the latest microcode version. The hang occurs as follows: The clock gate register is mapped into RCBA space. After reading the RCBA address from the LPC device config space no mask is applied to the value (only bits 31..14 are valid while bit 0 is the enable bit). For this reason the final address is off by one. The old microcodes at least allowed this unaligned access to the RCBA space. With the latest microcode this access leads to CPU hang. Once this is fixed the next issue occurs: After setting the clock gating bit for SMBus (bit 5) the SMBus controller disappears from the PCI bus completely and hence no usage of it is possible anymore. To fix this issue the clock gating code is completely removed as it was intentionally meant to enable clock gating on the SMB_CLK line and not the clock gating on the PCIe interface of the SMBus controller. This issue is known already and was discussed on the mailinglist: [coreboot] BDX-DE PCI init fail https://mail.coreboot.org/pipermail/coreboot/2018-January/085908.html TEST=Boot mc_bdx1 with microcode version M1050663_07000012. Change-Id: Icb86f4516f8a6e72552a44618737e682b0fdef33 Signed-off-by: Werner Zeh <werner.zeh@siemens.com> Reviewed-on: https://review.coreboot.org/25652 Reviewed-by: David Hendricks <david.hendricks@gmail.com> Reviewed-by: Aaron Durbin <adurbin@chromium.org> Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net> Tested-by: build bot (Jenkins) <no-reply@coreboot.org> |
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| 3rdparty | ||
| configs | ||
| Documentation | ||
| payloads | ||
| src | ||
| util | ||
| .checkpatch.conf | ||
| .clang-format | ||
| .gitignore | ||
| .gitmodules | ||
| .gitreview | ||
| COPYING | ||
| gnat.adc | ||
| MAINTAINERS | ||
| Makefile | ||
| Makefile.inc | ||
| README | ||
| toolchain.inc | ||
------------------------------------------------------------------------------- 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_TOOLCHAIN Kconfig 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 menuconfig' and 'make 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: https://www.coreboot.org 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.