[U-Boot] merge arm64 to arm

[FengHua]

> -----原始邮件-----
> 发件人: "Måns Rullgård" <mans at mansr.com>
> 发送时间: 2013年8月17日 星期六
> 收件人: FengHua <fenghua at phytium.com.cn>
> 抄送: u-boot at lists.denx.de, trini at ti.com, scottwood at freescale.com
> 主题: Re: merge arm64 to arm
> 
> FengHua <fenghua at 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.
> 
> -- 
> Måns Rullgård
> mans at mansr.com

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.