[SOLVED] Is using bios-e820 enough to locate ACPI ?

[wichtounet]

Hi,

I'm working on ACPI support in my OS right now and I've got a simple question.

I'm using the technique described here (http://forum.osdev.org/viewtopic.php?t=16990) to find the RSDTPtr, but the address I found is exactly what I have in the memory map given by e820 from BIOS.

Wouldn't it be enough in practice to use the e820 memory map to find ACPI ? Or are there some limitations in practice ?

Thanks

[jnc100]

In short no, it isn't. If it works on your particular machine/emulator then that is by pure luck only and you cannot guarantee it to work on others. Also, I'd strongly advise against using the shutdown code provided in that post you reference as it is seriously dependent on a particular layout of the particular AML code for the shutdown object.

Regards,
John.

[wichtounet]

Thanks for the answer.

In short no, it isn't. If it works on your particular machine/emulator then that is by pure luck only and you cannot guarantee it to work on others.

Ok, so I won't do that

Also, I'd strongly advise against using the shutdown code provided in that post you reference as it is seriously dependent on a particular layout of the particular AML code for the shutdown object.

Yes, I saw that from the comments. As it seems to work on emulators well enough, I will still use it until my kernel is ready for ACPICA. But it is only temporary

Thanks