I worked out method 3 too...
Please let me know if you want method 3 only or together with method 1.
the detail about method 3:
copy _secondary_start from 1M above to 1M below and mask the start_eip
to 20bit only.
It will make _RAMBASE > 0x100000 can work with SMP...
BTW, why there are linuxbios(a)openbios.org and linubios(a)linuxbios.org?
From: Lu, Yinghai
Sent: Thursday, December 08, 2005 12:19 PM
To: Lu, Yinghai; yhlu; Eric W. Biederman; LinuxBIOS
Subject: RE: [LinuxBIOS] Fwd: [issue50] put pgtbl after 1M
For 128 cpu system, will use method one and only keep stack for bsp in
linuxbios_ram statck section. Other stack will be after pgtbl....
Anyway the Method is the best way if we can work it out, and that could
make code more simple...
[mailto:email@example.com] On Behalf Of Lu, Yinghai
Sent: Wednesday, December 07, 2005 4:52 PM
To: yhlu; Eric W. Biederman; LinuxBIOS
Subject: Re: [LinuxBIOS] Fwd: [issue50] put pgtbl after 1M
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
[mailto:firstname.lastname@example.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(a)openbios.org>
Date: Dec 7, 2005 12:43 AM
Subject: [issue50] put pgtbl after 1M
To: ollie(a)lanl.gov, rminnich(a)lanl.gov, stepan(a)openbios.org,
New submission from Yinghai Lu <yinghailu(a)gmail.com>om>:
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
320k, it will push the stack and heap cross the 0xa0000, the region for
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
nosy: ollie, rminnich, stepan, yhlu
title: put pgtbl after 1M
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