-----原始邮件----- 发件人: "Måns Rullgård" mans@mansr.com 发送时间: 2013年8月17日 星期六 收件人: FengHua fenghua@phytium.com.cn 抄送: "Måns Rullgård" mans@mansr.com, trini trini@ti.com, u-boot u-boot@lists.denx.de, "albert.u.boot" albert.u.boot@aribaud.net, scottwood scottwood@freescale.com 主题: Re: merge arm64 to arm
FengHua fenghua@phytium.com.cn writes:
FengHua fenghua@phytium.com.cn writes:
hi tom, hi albert, yes, it's right. the u-boot could be more uniformly and maintainable if merging armv8 to arm architecture. I will try to migrate arm64 to armv8 subarchitecture of arm. do you have any other advice?
Why? The architectures are vastly different, arm64 (aarch64) being only loosely inspired by the 32-bit arm. It is not like with x86/amd64 where a lot of code can be shared.
Of course, with a seperated architecture the arm64 code will be clear and simple. when it merged with arm a few file should be duplicated with the name "_v8" appended and many macro switch should be added. but most of the code will be in armv8 directory which paralleled with armv7. it seems that this implementation are more nice.
ARMv8 defines both a 32-bit (aarch32) and a 64-bit (aarch64) instruction set. The naming you are suggesting would be misleading.
aarch32 state is compatible with armv7. armv8 directory only provide aarch64 state support. as you said, it would be a little misleading.
-- Måns Rullgård mans@mansr.com