44ae0eacb8
This change adds support for allocating resources above the 4G boundary by making use of memranges for resource windows enabled in the previous CL. It adds a new resource flag IORESOURCE_ABOVE_4G which is used in the following ways: a) Downstream device resources can set this flag to indicate that they would like to have their resource allocation above the 4G boundary. These semantics will have to be enabled in the drivers managing the devices. It can also be extended to be enabled via devicetree. This flag is automatically propagated by the resource allocator from downstream devices to the upstream bridges in pass 1. It is done to ensure that the resource allocator has a global view of downstream requirements during pass 2 at domain level. b) Bridges have a single resource window for each of mem and prefmem resource types. Thus, if any downstream resource of the bridge requests allocation above 4G boundary, all the other downstream resources of the same type under the bridge will be allocated above 4G boundary. c) During pass 2, resource allocator at domain level splits IORESOURCE_MEM into two different memory ranges -- one for the window below 4G and other above 4G. Resource allocation happens separately for each of these windows. d) At the bridge level, there is no extra logic required since the resource will live entirely above or below the 4G boundary. Hence, all downstream devices of any bridge will fall within the window allocated to the bridge resource. To handle this case separately from that of domain, initializing of memranges for a bridge is done differently than the domain. Limitation: Resources of a given type at the bridge or downstream devices cannot live both above and below 4G boundary. Thus, if a bridge has some downstream resources requesting allocation for a given type above 4G boundary and other resources of the same type requesting allocation below 4G boundary, then all these resources of the same type get allocated above 4G boundary. BUG=b:149186922 TEST=Verified that resources get allocated above the 4G boundary correctly on volteer. Signed-off-by: Furquan Shaikh <furquan@google.com> Change-Id: I7fb2a75cc280a307300d29ddabaebfc49175548f Reviewed-on: https://review.coreboot.org/c/coreboot/+/39487 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Aaron Durbin <adurbin@chromium.org> |
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| util | ||
| .checkpatch.conf | ||
| .clang-format | ||
| .editorconfig | ||
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| AUTHORS | ||
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| MAINTAINERS | ||
| Makefile | ||
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| README.md | ||
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README.md
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 https://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:
Build Requirements
- make
- gcc / g++
Because Linux distribution compilers tend to use lots of patches. coreboot
does lots of "unusual" things in its build system, some of which break due
to those patches, sometimes by gcc aborting, sometimes - and that's worse -
by generating broken object code.
Two options: use our toolchain (eg. make crosstools-i386) or enable the
ANY_TOOLCHAINKconfig option if you're feeling lucky (no support in this case). - iasl (for targets with ACPI support)
- pkg-config
- libssl-dev (openssl)
Optional:
- doxygen (for generating/viewing documentation)
- gdb (for better debugging facilities on some targets)
- ncurses (for
make menuconfigandmake nconfig) - flex and bison (for regenerating parsers)
Building coreboot
Please consult https://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 https://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:
You can contact us directly on the coreboot mailing list:
https://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.