82fd7a8142
This patch adds the support for loading compressed firmware files. The primary motivation is to reduce the storage size; e.g. currently the files in /lib/firmware on my machine counts up to 419MB, while they can be reduced to 130MB by file compression. The patch introduces a new kconfig option CONFIG_FW_LOADER_COMPRESS. Even with this option set, the firmware loader still tries to load the original firmware file as-is at first, but then falls back to the file with ".xz" extension when it's not found, and the decompressed file content is returned to the caller of request_firmware(). So, no change is needed for the rest. Currently only XZ format is supported. A caveat is that the kernel XZ helper code supports only CRC32 (or none) integrity check type, so you'll have to compress the files via xz -C crc32 option. Since we can't determine the expanded size immediately from an XZ file, the patch re-uses the paged buffer that was used for the user-mode fallback; it puts the decompressed content page, which are vmapped at the end. The paged buffer code is conditionally built with a new Kconfig that is selected automatically. Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.