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249f9ccacb
We've traditionally tucked the framebuffer at the end of memory (above CBMEM) on ARM and declared it reserved through coreboot's resource allocator. This causes depthcharge to mark this area as reserved in the kernel's device tree, which may be necessary to avoid display corruption on handoff but also wastes space that the OS could use instead. Since rk3288 boards now have proper display shutdown code in depthcharge, keeping the framebuffer memory reserved across the handoff (and thus throughout the lifetime of the system) should no longer be necessary. For now let's just switch the rk3288 implementation to define it through memlayout instead, which is not communicated through the coreboot tables and will get treated as normal memory by depthcharge. Note that this causes it to get wiped in developer/recovery mode, which should not be a problem because that is done in response to VbInit() (long before any images are drawn) and 0 is the default value for a corebootfb anyway (a black pixel). Eventually, we might want to think about adding more memory types to coreboot's resource system (e.g. "reserved until kernel handoff", or something specifically for the frame buffer) to model this situation better, and maybe merge it with memlayout somehow. CQ-DEPEND=CL:239470 BRANCH=veyron BUG=chrome-os-partner:34713 TEST=Booted Jerry, noticed that 'free' now displays 0x7f000 more bytes than before (curiously not 0x80000 bytes, I guess there's some alignment waste in the kernel somewhere). Made sure the memory map output from coreboot looks as expected, there's no visible display corruption in developer/recovery mode and the 'cbmem' utility still works. Change-Id: I12b7bfc1b7525f5a08cb7c64f0ff1b174df252d4 Signed-off-by: Patrick Georgi <pgeorgi@chromium.org> Original-Commit-Id: 10afdba54dd5d680acec9cb3fe5b9234e33ca5a2 Original-Change-Id: I1950407d3b734e2845ef31bcef7bc59b96c2ea03 Original-Signed-off-by: Julius Werner <jwerner@chromium.org> Original-Reviewed-on: https://chromium-review.googlesource.com/240819 Original-Reviewed-by: David Hendricks <dhendrix@chromium.org> Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org> Reviewed-on: http://review.coreboot.org/9732 Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org> |
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| documentation | ||
| payloads | ||
| src | ||
| util | ||
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| COPYING | ||
| Makefile | ||
| Makefile.inc | ||
| README | ||
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------------------------------------------------------------------------------- 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.