Re: Reserving physical memory at boot time

H. Peter Anvin (
5 Mar 2003 07:04:51 -0800

Followup to: <>
By author: "Randy.Dunlap" <>
In newsgroup:
> OK, with feeling:
> I agree with you since the boot protocol is well-defined.
> Just to be clear, my comment was referring to
> Documentation/kernel-parameters.txt, not to any C code.
> And it would really be helpful to catch issues like this soon
> after they happen...

Unfortunately last time I commented on this the response was roughly
"well, the patch already made it into Linus' kernel, it's too late to
fix it now." That isn't exactly a very helpful response.

The mem= parameter has the semantic in the i386/PC boot protocol that
it specifies the top address of the usable memory region that begins
at 0x100000. It's a bit of a wart that the boot loaders have to be
aware of this, but it's so and it's been so for a very long time.


<> at work, <> in private!
"Unix gives you enough rope to shoot yourself in the foot."
Architectures needed: ia64 m68k mips64 ppc ppc64 s390 s390x sh v850 x86-64
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at