Re: [PATCH] EmbeddedPkg/PrePiLib: allocate code pages for DxeCore

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

On 13 March 2017 at 09:55, Michael Zimmermann <sigmaepsilon92@gmail.com> wrote:
> I had to include <Library/MemoryAllocationLib.h> because I was getting
> this error:
> EmbeddedPkg/Library/PrePiLib/PrePiLib.c: In function ‘AllocateCodePages’:
> EmbeddedPkg/Library/PrePiLib/PrePiLib.c:59:3: error: implicit
> declaration of function ‘FreePages’
> [-Werror=implicit-function-declaration]
> FreePages (Alloc, Pages);
>
> Other than that it works great(you can take this as a Tested-By).

Thanks!

> Sry if it's a stupid question because I didn't look into all of the
> protection code yet, but wouldn't this mark everything as
> Code(including Data)?

It will mark the entire DxeCore PE/COFF image read-write-execute.
Later on, if the sections are sufficiently aligned, it will remove
write permissions from the PE/COFF text section and remove executable
permissions from the PE/COFF data section. If the sections are not
sufficiently aligned, it will leave the entire region as RWX.