8e4a355773
This patch adds an option to build the ramstage as a reloctable binary. It uses the rmodule library for the relocation. The main changes consist of the following: 1. The ramstage is loaded just under the cmbem space. 2. Payloads cannot be loaded over where ramstage is loaded. If a payload is attempted to load where the relocatable ramstage resides the load is aborted. 3. The memory occupied by the ramstage is reserved from the OS's usage using the romstage_handoff structure stored in cbmem. This region is communicated to ramstage by an CBMEM_ID_ROMSTAGE_INFO entry in cbmem. 4. There is no need to reserve cbmem space for the OS controlled memory for the resume path because the ramsage region has been reserved in #3. 5. Since no memory needs to be preserved in the wake path, the loading and begin of execution of a elf payload is straight forward. Change-Id: Ia66cf1be65c29fa25ca7bd9ea6c8f11d7eee05f5 Signed-off-by: Aaron Durbin <adurbin@chromium.org> Reviewed-on: http://review.coreboot.org/2792 Reviewed-by: Ronald G. Minnich <rminnich@gmail.com> Tested-by: build bot (Jenkins) Reviewed-by: Aaron Durbin <adurbin@google.com>
------------------------------------------------------------------------------- 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.