Re: [PATCH v3 04/52] xen/arm: add .text.idmap in ld script for Xen identity map sections

[Julien Grall <julien@xxxxxxx>]

Hi Penny,

On 26/06/2023 04:33, Penny Zheng wrote:
> From: Wei Chen <wei.chen@xxxxxxx>
>
> Only the first 4KB of Xen image will be mapped as identity
> (PA == VA). At the moment, Xen guarantees this by having
> everything that needs to be used in the identity mapping
> in .text.header section of head.S, and the size will be
> checked by _idmap_start and _idmap_end at link time if this
> fits in 4KB.
>
> In a later patch, we will move the MMU specific code out
> of head.S. Although we can add .text.header to the new file
> to guarantee all identity map code still in the first 4KB.
> However, the order of these two files on this 4KB depends
> on the build tools. Currently, we use the build tools to
> process the order of objs in the Makefile to ensure that
> head.S must be at the top. But if you change to another
> build tools, it might not be the same result.
>
> In this patch we introduce a new section named .text.idmap
> in the region between _idmap_start and _idmap_end. And in
> Xen link script, we force the .text.idmap contents to linked
> after .text.header. This will ensure code of head.S always be
> at the top of Xen binary.
>
> Signed-off-by: Wei Chen <wei.chen@xxxxxxx>
> Signed-off-by: Penny Zheng <penny.zheng@xxxxxxx>
Now that this patch is only a single line change, I would fold it in the 
patch introducing the first user (i.e. patch #7).
Cheers,

--
Julien Grall