3eab7ed45e
This change shows the source structure for nvidia Tegra and Tegra124 SOC. The problem we are trying to solve is that there is a large amount of common code in the form of .c and .h files across many different Tegra SOCs. The solution is to provide common code in a single directory, but not to compile in the common code directory; rather, we compile in a directory for a given SOC. Different SOCs will sometimes need different bits of code from the common directory. Tegra common code lives in tegra/, but there is no makefile there: if a Tegra common file is needed in a SOC, it is referenced via a Makefile in a specific Tegra SOC. Another issue is includes. Include files in the common directory might be accessed by a piece of code in an SOC directory. More problematically, code in the common directory might require a file in an SOC directory. We don't want to put the SOC name in an #include path, e.g. in a C file in tegra/ is very undesirable, since we might be compiling for a tegra114. On some systems this is solved by a pre-pass which creates a set of symbolic links; on others with nested #ifdef in the common code which include different .h files depending on CPP variables. In previous years, both LinuxBIOS and coreboot have tried these solutions and found them inconvenient and error-prone. We choose to solve it by requiring explicit naming of part of the path of files that are in the common directory. This requirement, coupled with two -I directives in the Makefile.inc, allows common and SOC C code to incorporate both common and SOC .h files. .c and .h files -- SOC or common -- name include files in the common directory with the prefix tegra/, e.g. SOC files will be included from the SOC directory if they have no prefix: The full patch of clock.h will depend on what SOC is being compiled, which is desirable. In this way, a common file can pick up a specific SOC file without creating symlinks or other such tricky magic. We show this usage with one file, soc/nvidia/tega124/clock.c. This compiles. The last question is where to put the prototype for the function defined in this file -- soc.h? Change-Id: Iecb635cec70f24a5b3e18caeda09d04a00d29409 Signed-off-by: Ronald G. Minnich <rminnich@gmail.com> Reviewed-on: https://chromium-review.googlesource.com/171569 Reviewed-by: Ronald Minnich <rminnich@chromium.org> Tested-by: Gabe Black <gabeblack@chromium.org> Commit-Queue: Gabe Black <gabeblack@chromium.org> (cherry picked from commit 53e3bed868953f3da588ec90661d316a6482e27e) Signed-off-by: Isaac Christensen <isaac.christensen@se-eng.com> Reviewed-on: http://review.coreboot.org/6621 Tested-by: build bot (Jenkins)
------------------------------------------------------------------------------- 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.