AArch64/ARM64 Linux Kernel Work Still Ongoing

The ARMv8 64-bit architecture enablement, officially known as AArch64, is still ongoing for the Linux kernel.

Back in early July were the initial Linux kernel patches for AArch64. The initial code drop consisted of about 23,000 lines of code to enable this 64-bit ARMv8 support in Linux. More on the AArch64/ARMv8 Linux enablement was talked about last month at Debian's DebConf 12.

The AArch64 Linux kernel port wasn't merged into the Linux 3.6 kernel as some would have hoped, the code is still being touched. Catalin Marinas of ARM Holdings published the "v2" patch-set this week for the AArch64 architecture enablement. While AArch64 is what ARM prefers to officially call their 64-bit architecture, in this second version of the patches the code is now living in the "arch/arm64" directory and the architecture functions are also using the "amd64" name, per comments on the original patches that some kernel developers didn't like the "AArch64" name. However, via uname and elsewhere, this ARM 64-bit architecture will continue to be referred to as AArch64.

Aside from some AArch64 -> ARM64 renaming, NO_BOOTMEM is now enabled, mem= can be used as a kernel parameter for limiting the amount of memory rather than memory banks, support for ZONE_DMA32, a generic debconfig file is available, and there's various clean-ups and bug-fixes.

The 31 patches amounting to over 22,000 lines of new Linux kernel architecture code can be found on LKML.org. We'll see within a few months time whether the ARMv8 AArch64 kernel code will be ready for merging into the Linux 3.7 kernel.

Meanwhile, other AArch64/ARMv8 Linux work is still in progress as well such as enabling ARMv8 compiler support for GCC.