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ACPI help needed
Posted: Sat Sep 27, 2003 11:30 am
by Neo
I got the following output using the int 0x15,e820 interrupt. I read from the Ralph Brown list that the Types 1=available, 3=ACPI recalim memory and 4=ACPI NVS memory which must be saved between NVS sessions.
Values for System Memory Map address type:
01h memory, available to OS
02h reserved, not available (e.g. system ROM, memory-mapped device)
03h ACPI Reclaim Memory (usable by OS after reading ACPI tables)
04h ACPI NVS Memory (OS is required to save this memory between NVS
sessions)
other not defined yet -- treat as Reserved
-------------------------------------
Base | Length | Type |
---------- | ------------- | --------|
0x0 | 0x9FC00 | 1 |
0x9FCOO | 0x400 | 2 |
0xE0000 | 0x20000 | 2 |
0x100000 | 0x7DF0000 | 1 |
0x7EF0000 | 0x8000 | 3 |
0x7EF8000 | 0x8000 | 4 |
0x7F00000 | 0x100000 | 2 |
-------------------------------------
Now my question is what is ACPI ,ACPI memory and ACPI NVS session?
Also can I report the free space found as 128Mb(approx value) or as (0x9fc00+0x7df0000 = 0x7e8fc00) and can I add the ACPI memory to the free memory.
Please help me out here and thanx in advance.
Re:ACPI help needed
Posted: Mon Sep 29, 2003 3:31 am
by Pype.Clicker
ACPI is an interface for power management in newer BIOSes. It will for instance allow the system to suspend, resume, power down by software, etc.
you should check what i say, because i'm not a guru at ACPI, but afaik, i would say that '03' type is some memory that the BIOS will use for reporting system state, and that is free for use by the OS once you have enquired of how to use it, while the 'non-volatile memory' should be some special memory whose content is preserved even when system restarts, etc. as long as you remain in the same "ACPI session".
If you don't have ACPI implementation yet (and i doubt you want to bother with ACPI this soon), i would recommend you consider these whole types to be "reserved".
Re:ACPI help needed
Posted: Fri Oct 03, 2003 12:11 pm
by Neo
Can anyone else shed some light on this topic or is it not worth bothering about? ::)
Re:ACPI help needed
Posted: Fri Oct 03, 2003 3:21 pm
by uri
Quote from the ACPI spec (
http://www.acpi.info/DOWNLOADS/ACPIspec-2-0b.pdf - page 329):
ACPI defines four address range types; AddressRangeMemory, AddressRangeACPI, AddressRangeNVS,
and AddressRangeReserved as described in the table below:
Code: Select all
Address Range Types
Value Mnemonic Description
1 AddressRangeMemory This range is available RAM usable by the operating system.
2 AddressRangeReserved This range of addresses is in use or reserved by the system
and must not be used by the operating system.
3 AddressRangeACPI ACPI Reclaim Memory. This range is available RAM usable by
the OS after it reads the ACPI tables.
4 AddressRangeNVS ACPI NVS Memory. This range of addresses is in use or reserve
by the system and must not be used by the operating system.
This range is required to be saved and restored across an NVS
sleep.
Other Undefined Undefined. Reserved for future use. OSPM must treat any range
of this type as if the type returned was AddressRangeReserved.
I'd just treat all memory areas with type > 1 as reserved...
Re:ACPI help needed
Posted: Fri Oct 03, 2003 3:34 pm
by uri
...just realized you already knew that table, sorry
Re:ACPI help needed
Posted: Sat Oct 04, 2003 11:43 am
by Neo
Thanx for the info pal and btw the link is broken however i managed to get to the site.Thanx