[SeaBIOS] [Xen-devel] Re: [PATCH] SeaBIOS/Xen: Compute the low RAM memory size in the BDA according to the e820

[Julian Pidancet]

On Mon, Nov 14, 2011 at 1:23 PM, Keir Fraser <keir at xen.org> wrote:
> On 14/11/2011 08:53, "Keir Fraser" <keir.xen at gmail.com> wrote:
>
>> On 14/11/2011 03:36, "Kevin O'Connor" <kevin at koconnor.net> wrote:
>>
>>> On Xen, the PCI init code isn't used, so assuming this struct doesn't
>>> need to live in real "ram", I think it could live just about anywhere
>>> past the end of ram.  Even with pciinit.c, addresses over 0xfc00000
>>> (with the exception of a few bytes for hpet, apic, ioapic, and bios
>>> image) could be used.
>>
>> I suggest we stick it at FC000000, and shift hvmloader's mem_alloc()
>> starting address up by one page to FC001000. The acpi build code will have
>> to manually mem_hole_populate_ram() that one page before writing to it. This
>> can then be documented in hvmloader/config.h which contains a description
>> of, and defines for, the system memory map. This is by far the easiest
>> solution to this problem; manually crafting an SSDT is a right pain in the
>> arse, whereas this is maybe a 5-line patch.
>
> Like the attached patch (untested), which is a bit larger than anticipated,
> but actually allows code to be net deleted. :-)
>

That was quick. I will give it a try shortly.

-- 
Julian