165 lines
4 KiB
C
165 lines
4 KiB
C
/* -*- Mode: C; c-basic-offset: 3 -*-
|
|
*
|
|
* apm.c - Support for the legacy Advanced Power Management (APM) BIOS
|
|
*
|
|
* This file is part of Metalkit, a simple collection of modules for
|
|
* writing software that runs on the bare metal. Get the latest code
|
|
* at http://svn.navi.cx/misc/trunk/metalkit/
|
|
*
|
|
* Copyright (c) 2009 Micah Dowty
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person
|
|
* obtaining a copy of this software and associated documentation
|
|
* files (the "Software"), to deal in the Software without
|
|
* restriction, including without limitation the rights to use,
|
|
* copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
* copies of the Software, and to permit persons to whom the
|
|
* Software is furnished to do so, subject to the following
|
|
* conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be
|
|
* included in all copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
|
|
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
|
|
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
|
|
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
|
|
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
|
|
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
|
|
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
|
|
* OTHER DEALINGS IN THE SOFTWARE.
|
|
*/
|
|
|
|
#include "apm.h"
|
|
#include "bios.h"
|
|
#include "intr.h"
|
|
|
|
APMState gAPM;
|
|
|
|
/*
|
|
* APM_Init --
|
|
*
|
|
* Probe for APM support. If APM is available, this connects to APM.
|
|
*
|
|
* It would be easier to use the 16-bit real mode interface via
|
|
* Metalkit's BIOS module, but that wouldn't work very well for us
|
|
* because we can't handle interrupts during a real-mode BIOS call.
|
|
* So, any APM_Idle() call would hang!
|
|
*
|
|
* Instead, we need to use 16-bit BIOS calls to bootstrap APM, then
|
|
* we do our real work via the 32-bit APM interface that is present
|
|
* in all APM 1.2 BIOSes.
|
|
*
|
|
* On exit, gAPM will have a valid 'connected' flag, APM version,
|
|
* and flags.
|
|
*/
|
|
|
|
fastcall void
|
|
APM_Init()
|
|
{
|
|
APMState *self = &gAPM;
|
|
Regs reg = {};
|
|
|
|
/* Real mode "APM Installation Check" call */
|
|
reg.ax = 0x5300;
|
|
reg.bx = 0x0000;
|
|
BIOS_Call(0x15, ®);
|
|
if (reg.bx == SIGNATURE_APM && reg.cf == 0) {
|
|
self->version = reg.ax;
|
|
self->flags = reg.cx;
|
|
} else {
|
|
return;
|
|
}
|
|
|
|
/* Real-mode interface connect */
|
|
reg.ax = 0x5303;
|
|
reg.bx = 0x0000;
|
|
BIOS_Call(0x15, ®);
|
|
if (reg.cf != 0) {
|
|
return;
|
|
}
|
|
|
|
/* Indicate that we want APM v1.2 */
|
|
reg.ax = 0x530e;
|
|
reg.bx = 0x0000;
|
|
reg.cx = 0x0102;
|
|
BIOS_Call(0x15, ®);
|
|
if (reg.cf != 0) {
|
|
return;
|
|
}
|
|
|
|
/* Success! */
|
|
self->connected = TRUE;
|
|
}
|
|
|
|
|
|
/*
|
|
* APM_Idle --
|
|
*
|
|
* If we're connected to APM, issue a "CPU Idle" call. The BIOS may
|
|
* halt the CPU until the next interrupt and/or slow or stop the
|
|
* CPU clock.
|
|
*
|
|
* If we aren't connected to APM or the APM call is unsuccessful,
|
|
* this issue a CPU HLT instruction.
|
|
*/
|
|
|
|
fastcall void
|
|
APM_Idle()
|
|
{
|
|
/*
|
|
* XXX: This doesn't actually work, because BIOS_Call disables
|
|
* interrupts! To get idle calls working, we'll need to use
|
|
* the real 32-bit APM interface.
|
|
*/
|
|
#if 0
|
|
|
|
APMState *self = &gAPM;
|
|
|
|
if (self->connected) {
|
|
Regs reg = {};
|
|
|
|
/* Real mode "CPU Idle" call */
|
|
reg.ax = 0x5305;
|
|
BIOS_Call(0x15, ®);
|
|
if (reg.cf == 0) {
|
|
/* Success */
|
|
return;
|
|
}
|
|
}
|
|
|
|
#endif
|
|
|
|
/* Fall back to CPU HLT */
|
|
Intr_Halt();
|
|
}
|
|
|
|
|
|
/*
|
|
* APM_SetPowerState --
|
|
*
|
|
* Set the power state of all APM-managed devices.
|
|
* If we aren't connected to APM, always fails.
|
|
*
|
|
* Returns TRUE on success, FALSE on error.
|
|
*/
|
|
|
|
fastcall Bool
|
|
APM_SetPowerState(uint16 state)
|
|
{
|
|
APMState *self = &gAPM;
|
|
|
|
if (self->connected) {
|
|
Regs reg = {};
|
|
|
|
reg.ax = 0x5307; // APM Set Power State
|
|
reg.bx = 0x0001; // All devices
|
|
reg.cx = state;
|
|
BIOS_Call(0x15, ®);
|
|
|
|
return reg.cf == 0;
|
|
}
|
|
|
|
return FALSE;
|
|
}
|