Effort Continues To Remove Most Of The SPARC 32-bit CPU Support From Linux

Last year saw a lot of code clean-up work on the Linux kernel and working to remove support for obsolete hardware no longer being actively maintained within the mainline kernel tree for years. On the CPU side one of the efforts has been to remove unused SPARC 32-bit CPU support for old Sun workstations. The patches for removing unused SPARC32 code was updated this weekend and now undergoing review.

Sam Ravnborg sent out 28 patches for the second revision to the patches for dropping Sun4m and Sun4d code from the mainline Linux kernel. Dropping these old SPARC 32-bit CPUs lightens the kernel source tree by 11k lines of unmaintained code.

This patch series though doesn't eliminate SPARC 32-bit support entirely as it leaves in just enough for the Frontgrade Gaisler LEON3 processors that are 32-bit SPARC processors still in use with the upstream Linux kernel. Meanwhile with the code being dropped, the Sun4D "Dragon" was great for its day in the early 90's with the SPARCserver 1000 and SPARCcenter 2000 but is obviously long obsolete. The Sun4M as a multi-processor Sun-4 variant is also a museum relic from the SunOS 4.1+ and Solaris 2 days.

"The sun4m and sun4d parts of the kernel have seen no real interest for several years now. Last time a few people surfaced, but it was either due to a personal project or for nostalgic reasons. It is time to let go and drop the parts of sparc32 that in reality are not in use.
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Removing sun4m and sun4d support allowed removal of the run time patching of the code as well as a lot of assembler code. The result is a much cleaner assembler code that is easier to understand and thus maintain and extend."

This latest Sun4M/Sun4D code removal work for the kernel can be found on the LKML.