No description
dffd892e47
A typical SPI operation consists of two phases - command and data
transfers. Command transfer is always from the host to the chip (i.e.
is going in the 'write' direction), data transfer could be either read
or write.
We don't want the receive FIFO to be operating while the command phase
is in progress. A simple way to keep the receive FIFO shut down is to
not to enable it until the command phase is completed.
Selective control of the receive FIFO allows to consolidate the
receive and transmit functions in a single spi_xfer() function, as it
happens in other SPI controller drivers.
The FIFO FULL and FIFO NOT EMPTY conditions are used to decide if the
next byte can be written or received, respectively. While data is
being received the 0xFF bytes are transmitted per each received byte,
to keep the SPI bus clocking.
The data structure describing the three GSBI ports is moved from the
.h file into .c file. A version of the clrsetbits macro is added to
work with integer addresses instead of pointers.
BUG=chrome-os-partner:27784
TEST=not yet, but with the res of the changes the bootblock loads and
starts the rombase section successfully.
Original-Change-Id: I78cd0054f1a8f5e1d7213f38ef8de31486238aba
Original-Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/197779
Original-Reviewed-by: Stefan Reinauer <reinauer@chromium.org>
Original-Reviewed-by: David Hendricks <dhendrix@chromium.org>
(cherry picked from commit c101ae306d182bbe14935ee139a25968388d745a)
Signed-off-by: Marc Jones <marc.jones@se-eng.com>
Change-Id: I7f3fd0524ec6c10008ff514e8a8f1d14a700732f
Reviewed-on: http://review.coreboot.org/7983
Reviewed-by: David Hendricks <dhendrix@chromium.org>
Tested-by: build bot (Jenkins)
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| 3rdparty@a8b0c52850 | ||
| 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.