[LinuxBIOS] Fwd: [issue50] put pgtbl after 1M

Lu, Yinghai yinghai.lu at amd.com
Thu Dec 8 01:52:14 CET 2005

Regarding the problem there are three way to solve.
1. move the pgtbl after 1M. this should work for a while....
	the future 32 node abd quad core = 128 cpu, will have stack
128*8=1M, It will cross the 0xa000 again...
2. in linuxbios_ram.ld, force bss, stack and heap all after 1M, the
total ram section will be larger then 1M  (about 1.5M),
(linuxbios_ram.bin still about 64K), it works well except the back and
forth in two linuebios ram image in jmp_to_elf_entry  will clear the
0xf0000-0x100000, the irq table ( and acpi region ) region 
3. the best solution seems to set _RAMBASE=0x10400, so it will not clear
our irq table and acpi tables...., the only thing to do is some 16 bit
code in secondary.S need to move to rom....other wise the ap can not be


-----Original Message-----
From: linuxbios-bounces at openbios.org
[mailto:linuxbios-bounces at openbios.org] On Behalf Of yhlu
Sent: Wednesday, December 07, 2005 12:47 AM
To: Eric W. Biederman; LinuxBIOS
Subject: [LinuxBIOS] Fwd: [issue50] put pgtbl after 1M


I moved the pgtbl to the last 1M of CONFIG_LB_MEM_TOPK....

Please check it.


---------- Forwarded message ----------
From: Yinghai Lu <lxbios at openbios.org>
Date: Dec 7, 2005 12:43 AM
Subject: [issue50] put pgtbl after 1M
To: ollie at lanl.gov, rminnich at lanl.gov, stepan at openbios.org,
yinghailu at gmail.com

New submission from Yinghai Lu <yinghailu at gmail.com>:

This one is needed for 8 way dual core with VGA support enabled.
The reason is every cpu page table will be 20k, and if there is 16 cpu
will need
320k, it will push the stack and heap cross the 0xa0000, the region for
vga font
buffer. TO use that need to set CONFIG_LB_MEM_TOPK in MB Options.lb
It also remove the hardcode 1M in clear_1m_ram.c to use


files: 1207_put_pgtbl_after_1m.diff
messages: 299
nosy: ollie, rminnich, stepan, yhlu
priority: urgent
status: chatting
title: put pgtbl after 1M

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