Re: 2.4.19 - 2.4.20 : Boot parameter MEM= doesn't work anymore

[Dick Streefland]

On Tuesday 2003-01-14 14:39, Guillaume Allard wrote:
| Hi
| It seems that the boot parameter MEM= doesn't work anymore with the
| kernel 2.4.19 and 2.4.20.
| This parameter allows to force the amount of RAM for old computer that
| linux kernel doesn't found.
| 
| I am using a debian woody with lilo 22.2.
| The computer is an old compaq with a pentium 150MHz and 64Mb of memory.
| The kernel only see 16Mb of memory.
| 
| Here you can find the kernel boot messages, we can see that the kernel
| receve the parameters (Kernel command line: auto BOOT_IMAGE=Linux ro
| root=802 mem=64M) but that it doesn't work (Memory: 13608k/16384k
| available (1327k kernel code, 2388k reserved, 410k data, 256k init, 0k
| highmem).

For some reason, the interpretation of the mem= kernel parameter was
changed. I ran into this myself. The value is now used to limit the
memory size, not overrule it. There is a different syntax for adding
memory. One of my computers has 128 Mb, of which only 64 Mb are
detected. I had to add the "mem=63m@65m" kernel parameter, resulting in:

BIOS-provided physical RAM map:
BIOS-88: 0000000000000000 - 000000000009f000 (usable)
BIOS-88: 0000000000100000 - 00000000040ffc00 (usable)
128MB LOWMEM available.
On node 0 totalpages: 32768
zone(0): 4096 pages.
zone(1): 28672 pages.
zone(2): 0 pages.

Unfortunately, this is not documented. Look at arch/i386/kernel/setup.c
for details.

-- 
Dick Streefland                      ////                      Altium BV
[e-mail]           (@ @)          http://www.altium.com
--------------------------------oOO--(_)--OOo---------------------------