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Message |
Steve West
Guest
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 Posted:
Mon Dec 06, 2004 8:57 pm Post subject:
pc motherboard power down |
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Does any one know how to turn off a pc motherboard automatically? I would
like my embedded pc code to power down a pc motherboard.
Steve |
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Frank Bemelman
Guest
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| Posted:
Mon Dec 06, 2004 9:21 pm Post subject:
Re: pc motherboard power down |
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"Steve West" <misc@sgwest.com> schreef in bericht
news:Oj%sd.151975$5K2.31443@attbi_s03...
| Quote: | Does any one know how to turn off a pc motherboard automatically? I would
like my embedded pc code to power down a pc motherboard.
|
If the flavour of your motherboard's powermanagement is APM 1.2
try this:
http://web.mit.edu/afs/sipb/contrib/doc/specs/protocol/apm12.pdf
--
Thanks, Frank.
(remove 'q' and 'invalid' when replying by email) |
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Steve West
Guest
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| Posted:
Mon Dec 06, 2004 9:34 pm Post subject:
Re: pc motherboard power down |
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are running protected mode and have no bios code after the initial boot. I
would like to just set a register and have the pc power down (like a
keyboard reboot).
Steve
Steve |
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Frank Bemelman
Guest
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| Posted:
Mon Dec 06, 2004 10:05 pm Post subject:
Re: pc motherboard power down |
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"Steve West" <misc@sgwest.com> schreef in bericht
news:ES%sd.152034$5K2.125825@attbi_s03...
| Quote: |
If the flavour of your motherboard's powermanagement is APM 1.2
try this:
http://web.mit.edu/afs/sipb/contrib/doc/specs/protocol/apm12.pdf
This looks like you need a power management driver to talk to the bios. We
are running protected mode and have no bios code after the initial boot.
I
would like to just set a register and have the pc power down (like a
keyboard reboot).
|
Well, the document describes the bios calls so that you could
actually write a PM driver. If you don't have a bios, you have
to re-write (part of) the PM bios that came with the board, and
likely need to know how the hardware does it all, on your particular
board. I'd think you need the schematics and datasheets on the
chipsets used, for starters.
--
Thanks, Frank.
(remove 'q' and 'invalid' when replying by email) |
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Nicholas O. Lindan
Guest
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| Posted:
Tue Dec 07, 2004 1:22 am Post subject:
Re: pc motherboard power down |
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"Steve West" <misc@sgwest.com> wrote
| Quote: | This looks like you need a power management driver to talk to the bios. We
are running protected mode ... [forever & ever] ...
|
Doesn't that imply the application software does not have the
authority to turn the power off?
How about:
1) Exit protected mode.
2) Call the bios to turn off the power.
After all, it is a one-way trip.
What does a disassembly of the OS's 'power-off' driver and the relevant bios
show?
--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.
Remove spaces etc. to reply: n o lindan at net com dot com
psst.. want to buy an f-stop timer? nolindan.com/da/fstop/ |
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Ed Beroset
Guest
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| Posted:
Tue Dec 07, 2004 6:44 am Post subject:
Re: pc motherboard power down |
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Steve West wrote:
| Quote: | If the flavour of your motherboard's powermanagement is APM 1.2
try this:
http://web.mit.edu/afs/sipb/contrib/doc/specs/protocol/apm12.pdf
This looks like you need a power management driver to talk to the bios. We
are running protected mode and have no bios code after the initial boot. I
would like to just set a register and have the pc power down (like a
keyboard reboot).
|
If all you want to do is turn off the computer, you don't really need a
while driver. There are two basic ways to do it. One would be to
simply return to real mode and then invoke the Connect request followed
immediately by the Set Power State call. The real mode code would be this:
ConnectAPM:
mov ax,5301h ; Real Mode APM connect
xor bx,bx ; APM BIOS
int 15h
PowerDown:
mov ax,5307h ; APM Set Power State
mov bx,1 ; all managed devices
mov cx,3 ; state=off
int 15h ; call APM
If you're willing to accept the complete lack of error checking, that's
all there is to it.
Ed |
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Tauno Voipio
Guest
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| Posted:
Tue Dec 07, 2004 12:01 pm Post subject:
Re: pc motherboard power down |
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Ed Beroset wrote:
| Quote: | Steve West wrote:
If the flavour of your motherboard's powermanagement is APM 1.2
try this:
http://web.mit.edu/afs/sipb/contrib/doc/specs/protocol/apm12.pdf
This looks like you need a power management driver to talk to the
bios. We are running protected mode and have no bios code after the
initial boot. I would like to just set a register and have the pc
power down (like a keyboard reboot).
If all you want to do is turn off the computer, you don't really need a
while driver. There are two basic ways to do it. One would be to
simply return to real mode and then invoke the Connect request followed
immediately by the Set Power State call. The real mode code would be this:
ConnectAPM:
mov ax,5301h ; Real Mode APM connect
xor bx,bx ; APM BIOS
int 15h
PowerDown:
mov ax,5307h ; APM Set Power State
mov bx,1 ; all managed devices
mov cx,3 ; state=off
int 15h ; call APM
If you're willing to accept the complete lack of error checking, that's
all there is to it.
Ed
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Ed:
Please read again - this does not work in *protected mode*.
--
Tauno Voipio
tauno voipio (at) iki fi |
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Ed Beroset
Guest
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| Posted:
Tue Dec 07, 2004 4:54 pm Post subject:
Re: pc motherboard power down |
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Tauno Voipio wrote:
| Quote: | Ed Beroset wrote:
Steve West wrote:
If the flavour of your motherboard's powermanagement is APM 1.2
try this:
http://web.mit.edu/afs/sipb/contrib/doc/specs/protocol/apm12.pdf
This looks like you need a power management driver to talk to the
bios. We are running protected mode and have no bios code after the
initial boot. I would like to just set a register and have the pc
power down (like a keyboard reboot).
If all you want to do is turn off the computer, you don't really need
a while driver. There are two basic ways to do it. One would be to
simply return to real mode and then invoke the Connect request
followed immediately by the Set Power State call. The real mode code
would be this:
ConnectAPM:
mov ax,5301h ; Real Mode APM connect
xor bx,bx ; APM BIOS
int 15h
PowerDown:
mov ax,5307h ; APM Set Power State
mov bx,1 ; all managed devices
mov cx,3 ; state=off
int 15h ; call APM
If you're willing to accept the complete lack of error checking,
that's all there is to it.
Please read again - this does not work in *protected mode*.
|
Please read my reply again -- I said "return to real mode and then..."
In fact, APM calls can be made from within protected mode as well, if
the BIOS supports it (mandatory starting with APM version 1.2). The
only catch is that the ConnectAPM call needs to be made from within real
mode. It then returns selectors which are then used to CALL the APM
routines instead of using the INT instruction. I assumed, however, that
this was more effort since it would involve modifying the early startup
real mode code. That code is almost identical, however:
ConnectAPMProt32:
mov ax,5303h ; 32-bit pmode APM connect request
xor bx,bx ; APM BIOS
int 15h ;
; if successful (CY = 0), then store returned values into GDT;
; see spec for details
The code that actually does the shutdown does indeed work in protected mode:
PowerDownProt32:
mov ax,5307h ; APM Set Power State
mov bx,1 ; all powered devicess
mov cx,3 ; state = off
call APM_SEL:APM_OFFS
The only other variation is 16-bit pmode code, which is almost identical.
Ed |
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