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SubjectRe: Reserving physical memory at boot time
Hi!

> > Really? So user has to know where ACPI tables are and specify less
> > than that on mem= command line? That seems very
> > counter-intuitive. [Ahha, its probaly okay because e820 saves you.]
> >
> > What do you pass on 4GB machine as mem= parameter? AFAIK those beasts
> > have hole at 3.75G. [Hopefully bigmem machines have working e820
> > tables?]
> >
>
> If you pass mem= you have to pass mem=3840M. Yes, it sucks, but if you
> genuinely have a machine which is so fucked up that you can't rely on
> the memory map the BIOS presents to you, you have problems to begin with.
>
> Oh yes, this is why GRUB passing the mem= parameter gratuitously was
> beyond total and complete brainfuckage.

Okay; which mem= options you want killed?

What about this?
Pavel

--- clean/arch/i386/kernel/setup.c 2003-03-06 23:25:14.000000000 +0100
+++ linux/arch/i386/kernel/setup.c 2003-03-08 00:18:21.000000000 +0100
@@ -527,6 +527,9 @@
* to <mem>, overriding the bios size.
* "mem=XXX[KkmM]@XXX[KkmM]" defines a memory region from
* <start> to <start>+<mem>, overriding the bios size.
+ *
+ * HPA tells me bootloaders need to parse mem=, so no new
+ * option should be mem=
*/
if (c == ' ' && !memcmp(from, "mem=", 4)) {
if (to != command_line)
@@ -535,8 +538,24 @@
from += 9+4;
clear_bit(X86_FEATURE_PSE, boot_cpu_data.x86_capability);
disable_pse = 1;
- } else if (!memcmp(from+4, "exactmap", 8)) {
- from += 8+4;
+ } else {
+ /* If the user specifies memory size, we
+ * limit the BIOS-provided memory map to
+ * that size. exactmap can be used to specify
+ * the exact map. mem=number can be used to
+ * trim the existing memory map.
+ */
+ unsigned long long start_at, mem_size;
+
+ mem_size = memparse(from+4, &from);
+ }
+ }
+
+ if (c == ' ' && !memcmp(from, "memmap=", 7)) {
+ if (to != command_line)
+ to--;
+ if (!memcmp(from+7, "exactmap", 8)) {
+ from += 8+7;
e820.nr_map = 0;
userdef = 1;
} else {
@@ -548,7 +567,7 @@
*/
unsigned long long start_at, mem_size;

- mem_size = memparse(from+4, &from);
+ mem_size = memparse(from+7, &from);
if (*from == '@') {
start_at = memparse(from+1, &from);
add_memory_region(start_at, mem_size, E820_RAM);
@@ -565,6 +584,7 @@
}
}

+
/* "acpi=off" disables both ACPI table parsing and interpreter init */
if (c == ' ' && !memcmp(from, "acpi=off", 8))
acpi_disabled = 1;

--
When do you have a heart between your knees?
[Johanka's followup: and *two* hearts?]
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