Re: Reserving a (large) memory block

From: Alan Cox (
Date: Thu Aug 31 2000 - 11:12:03 EST

> Now the device behaves just like memory to the BIOS during POST
> etc, and is in fact, exactly memory if no device drivers are loaded.
> If a device driver is loaded and it detects one or more of these
> devices then they and their memory ranges become obviously special.
> Now, we can detect the devices and where their address ranges are
> via the SMBUS and some careful probing so we know what we are trying
> to grab. The problem is just telling the rest of the kernel that in
> a clean VM&heap-happy manner.

Basically your base driver will have to do it at boot up time. Once that
memory is allocated to someone you may not be able to move the memory and
borrow the pages.

You don't neccessarily need the whole driver in the main kernel but you will
need to grab the devices, reserve the memory pages in question and mark them
as reserved before Linux gets going properly. Your actual users of these pages
can then be dynamically loaded.

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This archive was generated by hypermail 2b29 : Thu Aug 31 2000 - 21:00:27 EST