Messages in this thread | | | Date | Sun, 06 Feb 2011 15:32:34 -0800 | From | "H. Peter Anvin" <> | Subject | Re: [PATCH] NX protection for kernel data : fix 32 bits S3 suspend |
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On 02/06/2011 02:30 AM, Bodo Eggert wrote: > H. Peter Anvin <hpa@zytor.com> wrote: > >> In static_protections() we have: >> >>> /* >>> * The BIOS area between 640k and 1Mb needs to be executable for >>> * PCI BIOS based config access (CONFIG_PCI_GOBIOS) support. >>> */ > > I don't think the CGA/MDA/VGA graphics memory areas should be executable, > and I doubt execute access to these areas is required - is it? > > 0xA000:0000 might be a BIOS area, if it is, you don't have a VGA and the > ROM will be exactly 64K. 0xB800 and 0xB000 SHOULD NOT be a ROM, nobody dared > to use it (I don't remember exactly where ROMs are searched).
0xA0000..0xBFFFF can be ROM if you don't have a VGA card; this is new in PCI 3.x IIRC. However, in legacy systems you will not have ROM in this area.
-hpa
-- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.
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