3b02006afe
This change updates the resource allocator in coreboot to allow using multiple ranges for resource allocation rather than restricting available window to a single base/limit pair. This is done in preparation to allow 64-bit resource allocation. Following changes are made as part of this: a) Resource allocator still makes 2 passes at the entire tree. The first pass is to gather the resource requirements of each device under each domain. It walks recursively in DFS fashion to gather the requirements of the leaf devices and propagates this back up to the downstream bridges of the domain. Domain is special in the sense that it has fixed resource ranges. Hence, the resource requirements from the downstream devices have no effect on the domain resource windows. This results in domain resource limits being unmodified after the first pass. b) Once the requirements for all the devices under the domain are gathered, resource allocator walks a second time to allocate resources to downstream devices as per the requirements. Here, instead of maintaining a single window for allocating resources, it creates a list of memranges starting with the resource window at domain and then applying constraints to create holes for any fixed resources. This ensures that there is no overlap with fixed resources under the domain. c) Domain does not differentiate between mem and prefmem. Since they are allocated space from the same resource window at the domain level, it considers all resource requests from downstream devices of the domain independent of the prefetch type. d) Once resource allocation is done at the domain level, resource allocator walks down the downstream bridges and continues the same process until it reaches the leaves. Bridges have separate windows for mem and prefmem. Hence, unlike domain, the resource allocator at bridge level ensures that downstream requirements are satisfied by taking prefetch type into consideration. e) This whole 2-pass process is performed for every domain in the system under the assumption that domains do not have overlapping address spaces. Noticeable differences from previous resource allocator: a) Changes in print logs observed due to flows being slightly different. b) Base, limit and size of domain resources are no longer updated based on downstream requirements. c) Memranges are used instead of a single base/limit pair for determining resource allocation. d) Previously, if a resource request did not fit in the available base/limit window, then the resource would be allocated over DRAM or any other address space defeating the principle of "no overlap". With this change, any time a resource cannot fit in the available ranges, it complains and ensures that the resource is effectively disabled by setting base same as the limit. e) Resource allocator no longer looks at multiple links to determine the right bus for a resource. None of the current boards have multiple buses under any downstream device of the domain. The only device with multiple links seems to be the cpu cluster device for some AMD platforms. BUG=b:149186922 TEST=Verified that resource allocation looks correct based on addresses assigned on Volteer. Signed-off-by: Furquan Shaikh <furquan@google.com> Change-Id: Ia1f089877c62e119c6a994a10809c9cc0050ec9a Reviewed-on: https://review.coreboot.org/c/coreboot/+/39486 Reviewed-by: Aaron Durbin <adurbin@chromium.org> Tested-by: build bot (Jenkins) <no-reply@coreboot.org> |
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| LICENSES | ||
| payloads | ||
| src | ||
| tests | ||
| util | ||
| .checkpatch.conf | ||
| .clang-format | ||
| .editorconfig | ||
| .gitignore | ||
| .gitmodules | ||
| .gitreview | ||
| AUTHORS | ||
| COPYING | ||
| gnat.adc | ||
| MAINTAINERS | ||
| Makefile | ||
| Makefile.inc | ||
| README.md | ||
| 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 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.