coreboot/payloads/libpayload
Yu-Ping Wu b4f2a51533 libpayload/arch/arm64/mmu: Fix missing CBMEM in used ranges
We use mmu_ranges to track the list of memory ranges and their types for
MMU initialization. We also keep track of used memory ranges in
usedmem_ranges, to avoid them from being re-allocated in
mmu_alloc_range().

The problem is, the CBMEM range (CB_MEM_TABLE) is added to mmu_ranges,
but is never marked as "used" in usedmem_ranges. This potentially causes
any allocation (for example the framebuffer) to overlap with CBMEM. This
issue is observed when DMA_DEFAULT_SIZE is reduced from 32MB to 1MB [1].
Prior to that change, because there isn't enough space above the
coreboot table (with the 4GB upper limit) to fit the 32MB requested
region, the DMA heap is always allocated *below* the coreboot table. And
because the coreboot table is usually the lowest within CBMEM, the DMA
heap region is allocated *below* the whole CBMEM, which happens the
avoid the issue.

Fix the bug by adding CB_MEM_TABLE ranges to usedmem_ranges. The ranges
in usedmem_ranges don't need to be combined because they are not for MMU
initialization (and there's only one CB_MEM_TABLE range).

[1] commit aedc177f00 ("libpayload: arm64: Reduce DMA allocator space to 1MB")

BUG=b:424107889
TEST=emerge-skywalker libpayload
BRANCH=none

Change-Id: Ie9ecafc17546e524253c60ab684ec10ff3495998
Signed-off-by: Yu-Ping Wu <yupingso@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/88063
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Bartłomiej Grzesik <bgrzesik@google.com>
Reviewed-by: Jakub "Kuba" Czapiga <czapiga@google.com>
2025-06-13 15:23:09 +00:00
..
arch libpayload/arch/arm64/mmu: Fix missing CBMEM in used ranges 2025-06-13 15:23:09 +00:00
bin libpayload: Add x86_64 (64-bit) support 2024-05-26 01:26:31 +00:00
configs libpayload: configs: Add new config.featuretest to broaden CI 2024-12-04 22:25:34 +00:00
crypto payloads: Rename Makefiles from .inc to .mk 2024-01-24 10:15:10 +00:00
curses payloads: Rename Makefiles from .inc to .mk 2024-01-24 10:15:10 +00:00
drivers cbgfx: Prevent divide-by-zero edge case in Lanczos kernel 2025-05-06 21:04:04 +00:00
gdb libpayload: gdb: Make die_if() format string a literal 2024-03-19 22:50:03 +00:00
include Revert "libpayload: arm64: Reduce DMA allocator space to 1MB" 2025-06-11 19:45:49 +00:00
libc libpayload: Use Kconfig instead of weak symbol for arch_ndelay() 2025-05-22 19:27:30 +00:00
libcbfs libpayload: Remove legacy CBFS API 2024-02-22 21:18:39 +00:00
liblz4 payloads: Rename Makefiles from .inc to .mk 2024-01-24 10:15:10 +00:00
liblzma payloads: Rename Makefiles from .inc to .mk 2024-01-24 10:15:10 +00:00
libpci payloads: Rename Makefiles from .inc to .mk 2024-01-24 10:15:10 +00:00
sample libpayload: Add mock architecture 2021-10-11 12:59:57 +00:00
tests libpayload/arch/mock: Select ARCH_HAS_NDELAY for ARCH_MOCK 2025-05-28 00:15:29 +00:00
vboot libpayload: Add x86_64 (64-bit) support 2024-05-26 01:26:31 +00:00
.gitignore .gitignore: Split into subdirectory files 2020-10-30 07:05:27 +00:00
Doxyfile payloads: Remove/fix trailing whitespace 2018-09-04 12:38:40 +00:00
Kconfig libpayload: Use Kconfig instead of weak symbol for arch_ndelay() 2025-05-22 19:27:30 +00:00
LICENSE_GPL libpayload: Introduce new Kconfig to explicitly allow GPL code 2015-01-09 07:06:27 +01:00
LICENSES libpayload: Add LZ4 decompression algorithm 2015-07-09 00:10:16 +02:00
Makefile libpayload: Add x86_64 (64-bit) support 2024-05-26 01:26:31 +00:00
Makefile.mk payloads/libpayload/Makefile.mk: Replace nm with $(NM) 2025-06-05 13:37:27 +00:00
Makefile.payload libpayload/Makefile.payload: Add lto flags 2024-08-27 09:08:07 +00:00
README payloads/libpayload: Update a Makefile for sample libpayload 2019-06-21 09:16:36 +00:00

-------------------------------------------------------------------------------
libpayload README
-------------------------------------------------------------------------------

libpayload is a minimal library to support standalone payloads
that can be booted with firmware like coreboot. It handles the setup
code, and provides common C library symbols such as malloc() and printf().

Note: This is _not_ a standard library for use with an operating system,
rather it's only useful for coreboot payload development!
See https://www.coreboot.org for details on coreboot.


Installation
------------

 $ git clone https://review.coreboot.org/coreboot.git

 $ cd coreboot/payloads/libpayload

 $ make menuconfig

 $ make

 $ make install (optional, will install into ./install per default)

On x86 systems, libpayload will always be 32-bit even if your host OS runs
in 64-bit, so you might have to install the 32-bit libgcc version.
On Debian systems you'd do 'apt-get install gcc-multilib' for example.

Run 'make distclean' before switching boards. This command will remove
your current .config file, so you need 'make menuconfig' again or
'make defconfig' in order to set up configuration. Default configuration
is based on 'configs/defconfig'. See the configs/ directory for examples
of configuration.


Usage
-----

Here's an example of a very simple payload (hello.c) and how to build it:

 #include <libpayload.h>

 int main(void)
 {
     printf("Hello, world!\n");
     return 0;
 }

Building the payload using the 'lpgcc' compiler wrapper:

 $ lpgcc -o hello.elf hello.c

Please see the sample/ directory for details.


Website and Mailing List
------------------------

The main website is https://www.coreboot.org/Libpayload.

For additional information, patches, and discussions, please join the
coreboot mailing list at https://www.coreboot.org/Mailinglist, where most
libpayload developers are subscribed.


Copyright and License
---------------------

See LICENSES.