Re: [PATCH] Fix alignment of early reservation for EBDA

Andi Kleen
2008-02-24T19:27:53Z

On Sunday 24 February 2008 18:46:05 Alexander van Heukelum wrote:
> Hi Andi,
>
> My eyes fell on the following table in the boot messages:
>
> early res: 0 [0-fff] BIOS data page
> early res: 1 [6000-7fff] SMP_TRAMPOLINE
> early res: 2 [200000-374557] TEXT DATA BSS
> early res: 3 [9fc00-a0bff] EBDA
> early res: 4 [8000-afff] PGTABLE
>
> The memory reserved for the EBDA overflows into the area normally
> reserved for the VGA adaptor. It seems that you wanted to force
> the allocation to cover whole pages, like:
>
> early res: 3 [9f000-9ffff] EBDA
>
> This is what this patch implements.

Thanks.

> Is it really necessary to force the allocation to a page boundary?

In theory not, in practice it works around some problems in early
allocations where the other users assume page alignment.
At some point it needs to be cleaned up properly.

-Andi