| Author |
Message |
Zdenek Sojka
Guest
|
 Posted:
Thu Aug 18, 2005 4:15 pm Post subject:
BIOS usage in OS |
|
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Hello,
I hope this is not off topic:
I would like to know how much is BIOS code being used in modern (PM) OSs.
I know (suppose) it is used in power management,but what I dont understand
is how can new BIOS flash improve stability of my integrated NIC? And so
on... There are also VBE, which are no longer used altough they are ready
for PM calls.
Is there any code still run by some mmproc other than CPU? (e.g. BIOS flash
upgrades microcode in my NIC)
Or are there some BIOS calls when communicating via NIC? Or is there only
different inicialization?
(I have ASUS A8N-E with nForce 4 Ultra, and in BIOS notes there is a message
that I must upgrade nForce drivers to 6.66 or I risk a data loss... well, it
is true, but whe I turned on 48bit LBA in W2k, all seemed to be ok)
Anyway, there are many BIOS versions for each MB and usually it brings
different stability, CPU support etc., but often, there are also advantages
in OS run-time.
So - are there BIOS routines often being called while OS is running? (except
power management)
Thanks
Zdenek Sojka |
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|
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Andi Kleen
Guest
|
| Posted:
Thu Aug 18, 2005 10:30 pm Post subject:
Re: BIOS usage in OS |
|
|
"Zdenek Sojka" <XzsXojkaX@XseXznamX.dot.cz> writes:
| Quote: | I hope this is not off topic:
I would like to know how much is BIOS code being used in modern (PM) OSs.
|
Not very much. Some ACPI bytecode (ASL), some SMM code behind the OS
back (for more things than just power saving), sometimes VESA BIOS
code at boot. There used to be an 32bit PCI BIOS, but it has gotten
out of favour with modern chipsets. 64bit OS have cut back on this even more.
| Quote: | I know (suppose) it is used in power management,but what I dont understand
is how can new BIOS flash improve stability of my integrated NIC? And so
on... There are also VBE, which are no longer used altough they are ready
for PM calls.
|
First the BIOS sets up a lot of tables in ACPI that specify to the
OS how the hardware is laid out and put byte code in there that
does specific initialization.
But the big difference is how the BIOS sets up the hardware.
Modern chipsets and CPUs have hundreds or thousands of knobs
to tune their behaviour. In general the BIOS sets this
up, but sometimes it needs OS support for that
(e.g. it might depend in what modus the OS drives the interrupt
controller)
Another thing that BIOS do is to assign memory mappings
of devices to specific areas in the address space and interrupts and that
can also make a big difference.
| Quote: | Is there any code still run by some mmproc other than CPU? (e.g. BIOS flash
upgrades microcode in my NIC)
|
ASL byte code and SMM code.
| Quote: | Or are there some BIOS calls when communicating via NIC? Or is there only
different inicialization?
|
There are none usually after boot, but the chipset initialization affects it.
Also many modern NICs have firmware on their own that needs to be uploaded
by the drivers and executes in small CPUs on the NIC.
| Quote: | (I have ASUS A8N-E with nForce 4 Ultra, and in BIOS notes there is a message
that I must upgrade nForce drivers to 6.66 or I risk a data loss... well, it
is true, but whe I turned on 48bit LBA in W2k, all seemed to be ok)
Anyway, there are many BIOS versions for each MB and usually it brings
different stability, CPU support etc., but often, there are also advantages
in OS run-time.
So - are there BIOS routines often being called while OS is running? (except
power management)
|
Most of this code is only called during boot or card hotplug.
Hope this helps,
-Andi |
|
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|
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Zdenek Sojka
Guest
|
| Posted:
Fri Sep 02, 2005 11:42 pm Post subject:
Re: BIOS usage in OS |
|
|
Thanks for reply.
Sorry for delay, I was on Holidays
"Andi Kleen" <freitag@alancoxonachip.com> píse v diskusním príspevku
news:p733bp7tap0.fsf@verdi.suse.de...
| Quote: | "Zdenek Sojka" <XzsXojkaX@XseXznamX.dot.cz> writes:
I hope this is not off topic:
I would like to know how much is BIOS code being used in modern (PM)
OSs.
Not very much. Some ACPI bytecode (ASL), some SMM code behind the OS
back (for more things than just power saving), sometimes VESA BIOS
code at boot. There used to be an 32bit PCI BIOS, but it has gotten
out of favour with modern chipsets. 64bit OS have cut back on this even
more.
I know (suppose) it is used in power management,but what I dont
understand
is how can new BIOS flash improve stability of my integrated NIC? And so
on... There are also VBE, which are no longer used altough they are
ready
for PM calls.
First the BIOS sets up a lot of tables in ACPI that specify to the
OS how the hardware is laid out and put byte code in there that
does specific initialization.
But the big difference is how the BIOS sets up the hardware.
Modern chipsets and CPUs have hundreds or thousands of knobs
to tune their behaviour. In general the BIOS sets this
up, but sometimes it needs OS support for that
(e.g. it might depend in what modus the OS drives the interrupt
controller)
Another thing that BIOS do is to assign memory mappings
of devices to specific areas in the address space and interrupts and that
can also make a big difference.
Is there any code still run by some mmproc other than CPU? (e.g. BIOS
flash
upgrades microcode in my NIC)
ASL byte code and SMM code.
Or are there some BIOS calls when communicating via NIC? Or is there
only
different inicialization?
There are none usually after boot, but the chipset initialization affects
it.
Also many modern NICs have firmware on their own that needs to be uploaded
by the drivers and executes in small CPUs on the NIC.
(I have ASUS A8N-E with nForce 4 Ultra, and in BIOS notes there is a
message
that I must upgrade nForce drivers to 6.66 or I risk a data loss...
well, it
is true, but whe I turned on 48bit LBA in W2k, all seemed to be ok)
Anyway, there are many BIOS versions for each MB and usually it brings
different stability, CPU support etc., but often, there are also
advantages
in OS run-time.
So - are there BIOS routines often being called while OS is running?
(except
power management)
Most of this code is only called during boot or card hotplug.
Hope this helps,
-Andi |
|
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