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The Itanium architecture is obsolete, and an informal survey [0] reveals that any residual use of Itanium hardware in production is mostly HP-UX or OpenVMS based. The use of Linux on Itanium appears to be limited to enthusiasts that occasionally boot a fresh Linux kernel to see whether things are still working as intended, and perhaps to churn out some distro packages that are rarely used in practice. None of the original companies behind Itanium still produce or support any hardware or software for the architecture, and it is listed as 'Orphaned' in the MAINTAINERS file, as apparently, none of the engineers that contributed on behalf of those companies (nor anyone else, for that matter) have been willing to support or maintain the architecture upstream or even be responsible for applying the odd fix. The Intel firmware team removed all IA-64 support from the Tianocore/EDK2 reference implementation of EFI in 2018. (Itanium is the original architecture for which EFI was developed, and the way Linux supports it deviates significantly from other architectures.) Some distros, such as Debian and Gentoo, still maintain [unofficial] ia64 ports, but many have dropped support years ago. While the argument is being made [1] that there is a 'for the common good' angle to being able to build and run existing projects such as the Grid Community Toolkit [2] on Itanium for interoperability testing, the fact remains that none of those projects are known to be deployed on Linux/ia64, and very few people actually have access to such a system in the first place. Even if there were ways imaginable in which Linux/ia64 could be put to good use today, what matters is whether anyone is actually doing that, and this does not appear to be the case. There are no emulators widely available, and so boot testing Itanium is generally infeasible for ordinary contributors. GCC still supports IA-64 but its compile farm [3] no longer has any IA-64 machines. GLIBC would like to get rid of IA-64 [4] too because it would permit some overdue code cleanups. In summary, the benefits to the ecosystem of having IA-64 be part of it are mostly theoretical, whereas the maintenance overhead of keeping it supported is real. So let's rip off the band aid, and remove the IA-64 arch code entirely. This follows the timeline proposed by the Debian/ia64 maintainer [5], which removes support in a controlled manner, leaving IA-64 in a known good state in the most recent LTS release. Other projects will follow once the kernel support is removed. [0] https://lore.kernel.org/all/CAMj1kXFCMh_578jniKpUtx_j8ByHnt=s7S+yQ+vGbKt9ud7+kQ@mail.gmail.com/ [1] https://lore.kernel.org/all/0075883c-7c51-00f5-2c2d-5119c1820410@web.de/ [2] https://gridcf.org/gct-docs/latest/index.html [3] https://cfarm.tetaneutral.net/machines/list/ [4] https://lore.kernel.org/all/87bkiilpc4.fsf@mid.deneb.enyo.de/ [5] https://lore.kernel.org/all/ff58a3e76e5102c94bb5946d99187b358def688a.camel@physik.fu-berlin.de/ Acked-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
67 lines
1.6 KiB
Plaintext
67 lines
1.6 KiB
Plaintext
# SPDX-License-Identifier: GPL-2.0-only
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config XZ_DEC
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tristate "XZ decompression support"
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select CRC32
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help
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LZMA2 compression algorithm and BCJ filters are supported using
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the .xz file format as the container. For integrity checking,
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CRC32 is supported. See Documentation/staging/xz.rst for more information.
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if XZ_DEC
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config XZ_DEC_X86
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bool "x86 BCJ filter decoder" if EXPERT
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default y
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select XZ_DEC_BCJ
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config XZ_DEC_POWERPC
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bool "PowerPC BCJ filter decoder" if EXPERT
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default y
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select XZ_DEC_BCJ
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config XZ_DEC_ARM
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bool "ARM BCJ filter decoder" if EXPERT
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default y
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select XZ_DEC_BCJ
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config XZ_DEC_ARMTHUMB
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bool "ARM-Thumb BCJ filter decoder" if EXPERT
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default y
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select XZ_DEC_BCJ
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config XZ_DEC_SPARC
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bool "SPARC BCJ filter decoder" if EXPERT
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default y
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select XZ_DEC_BCJ
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config XZ_DEC_MICROLZMA
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bool "MicroLZMA decoder"
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default n
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help
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MicroLZMA is a header format variant where the first byte
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of a raw LZMA stream (without the end of stream marker) has
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been replaced with a bitwise-negation of the lc/lp/pb
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properties byte. MicroLZMA was created to be used in EROFS
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but can be used by other things too where wasting minimal
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amount of space for headers is important.
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Unless you know that you need this, say N.
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endif
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config XZ_DEC_BCJ
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bool
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default n
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config XZ_DEC_TEST
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tristate "XZ decompressor tester"
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default n
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depends on XZ_DEC
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help
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This allows passing .xz files to the in-kernel XZ decoder via
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a character special file. It calculates CRC32 of the decompressed
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data and writes diagnostics to the system log.
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Unless you are developing the XZ decoder, you don't need this
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and should say N.
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