Re: Reserving a (large) memory block

Date: Thu Aug 31 2000 - 14:48:59 EST

On Thu, 31 Aug 2000 11:32:21 -0500
Timur Tabi <> wrote:

> ** Reply to message from on Thu, 31 Aug 2000
> 08:57:20 -0700
>> 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.

> How do you know what SMBUS address to use? Probing the SMBUS
> looking for devices has a tendency to lock the SMBUS and require a
> complete power down to restore.

I didn't write the SMBUS code (the author is not on this list),
however, the basic SMBUS work was based off here:

At this point we've only tried/tested/looked_at GX chipset based SMP
MBs. Loosely we hit the chipset and get the specs for every
individual memory card, and look for something that looks like one
of our devices as per the SPDs (we have a mini in-driver
eeprom-style client setup to get the SPDs). The cards are then
identified as per a signature in the SPD.

J C Lawrence                                 Home:
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--=| A man is as sane as he is dangerous to his environment |=--
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