UMB question

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UMB question

Eric Auer-3

Hi kernel experts,

I vaguely remember that there is a pending patch where the kernel
is using a memcopy-style function residing in memory that already
got "freed" at that moment during boot, so I guess the gurus are
awake at the moment...

QUESTION: Would it be possible to improve UMB handling such that
the kernel supports SEVERAL providers of UMB at the same time, for
example UMBPCI for hardware-UMB and in addition EMM386 to "map" a
few more UMB to areas where normally a memory gap would be, such
as the "monochrome video memory" area?

Might be interesting to have even more UMB flexibility :-)

Regards, Eric


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Re: UMB question

tom ehlert


> Hi kernel experts,

> I vaguely remember that there is a pending patch where the kernel
> is using a memcopy-style function residing in memory that already
> got "freed" at that moment during boot,

to be precise: during INSTALL=

> so I guess the gurus are  awake at the moment...

> QUESTION: Would it be possible to improve UMB handling such that
> the kernel supports SEVERAL providers of UMB at the same time, for
> example UMBPCI for hardware-UMB and in addition EMM386 to "map" a
> few more UMB to areas where normally a memory gap would be, such
> as the "monochrome video memory" area?


UMBPCI is nice if you want to avoid EMM386 but have some UMB

EMM386 is nice in all other circumstances.

it just doesnt't make much sense to have both UMBPCI and EMM386 active
at the same time. if only for the reason that UMBPCI UMBs are
only *sometimes* able to support DMA, while EMM386 UMBs are always able to
use DMA, *provided you use VDMA services* (important for network
chips).


> Might be interesting to have even more UMB flexibility :-)
yes. wasting precious developer ours on useless suff and hear them
swear. very interesting indead.

definitively not worth the trouble.


Tom


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