For the past several months, I have been working with Linaro [1], an association of companies who want to see GNU/Linux working well on ARM architectures. Although ARM Holdings designs the ARM architecture chips, various other companies manufacture the CPUs, GPUs, and SoCs (Systems on a Chip) from ARM's licensed designs. Some of these companies use these manufactured units in their own products, and some sell the manufactured units to other companies and to the general public. For the past couple of years, ARM has been working on a 64-bit chip, and their licensees are getting close to having ARM 64-bit hardware ready.

One of the ARM engineers determined that 1,400 different source code modules in either Ubuntu or Fedora (or both) have assembly language in the code. This is not to say that the assembly language (or lack of it) will stop the module from working on the ARM64 system, because there may be higher level fallback code (e.g., code written in C) that will take over and be compiled for the missing ARM64 assembly language. However, the modules have not been tested and verified either on actual hardware or on the emulators for the ARM64 architecture that currently exist. Thus, Linaro decided to enlist the community in porting some of these modules and has created a contest with prizes for those people who help out [2].

The engineers also noticed that a lot of the code containing assembly language was fairly old. It was designed in an age when systems had a single CPU; CPUs were much slower, with a single core; memory was measured in megabytes, not gigabytes; Ethernet was 10Mbps, not 1,000Mbps; and the GNU compilers were not as good at optimization as commercial compilers. Therefore, people wrote assembler for the tightest, fastest parts of the system.

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