No description
44f465d21c
The SPI controller operates on packets which can be variable length up to 32-bit packets. It also has the ability to be put in packed or unpacked mode w.r.t each packet. i.e. does a single fifo register hold >= 1 packet. The current programming uses 8-bit packets in unpacked mode which means 4 fifo slots are used for a 32-bit DMA transfter. As the AHB can only operate on a minimum of 32-bit bursts the triggers need to be programmed correctly so that there is room for a full 32-bit DMA transaction. Previously faster SPI clocks just made things magically work. BUG=chrome-os-partner:30779 BRANCH=None TEST=Built and booted through coreboot with 20MHz SPI clock. Original-Change-Id: I3f1cd4dddcea9514327b2363ed450a527db7e1fe Original-Signed-off-by: Aaron Durbin <adurbin@chromium.org> Original-Reviewed-on: https://chromium-review.googlesource.com/208862 Original-Reviewed-by: Tom Warren <twarren@nvidia.com> Original-Reviewed-by: Furquan Shaikh <furquan@chromium.org> Original-Commit-Queue: Furquan Shaikh <furquan@chromium.org> (cherry picked from commit d9864228a2479e412d7e0d2221fe536f78329acd) Signed-off-by: Marc Jones <marc.jones@se-eng.com> Change-Id: I61c145f35e1f889d4f83f3dfea049bfd347c1196 Reviewed-on: http://review.coreboot.org/8649 Tested-by: build bot (Jenkins) Reviewed-by: Furquan Shaikh <furquan@google.com> |
||
---|---|---|
3rdparty@2bc495fd31 | ||
documentation | ||
payloads | ||
src | ||
util | ||
.gitignore | ||
.gitmodules | ||
.gitreview | ||
COPYING | ||
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 http://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: * http://www.coreboot.org/Supported_Motherboards * http://www.coreboot.org/Supported_Chipsets_and_Devices Build Requirements ------------------ * gcc / g++ * make Optional: * doxygen (for generating/viewing documentation) * iasl (for targets with ACPI support) * gdb (for better debugging facilities on some targets) * ncurses (for 'make menuconfig') * flex and bison (for regenerating parsers) Building coreboot ----------------- Please consult http://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 http://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: http://www.coreboot.org You can contact us directly on the coreboot mailing list: http://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.