freebsd-dev/sys/boot/i386/libi386/biosacpi.c
Mike Smith ad41f9a8f7 Teach the loader how to find the system ACPI information, and autoload
the ACPI module if the system apperars to be ACPI compliant.

This is an initial cut; the load should really be done by Forth support
code, and we should check both the BIOS build date and a blacklist.
2001-08-30 00:42:12 +00:00

127 lines
3.6 KiB
C

/*-
* Copyright (c) 2001 Michael Smith <msmith@freebsd.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <stand.h>
#include <machine/stdarg.h>
#include <bootstrap.h>
#define COMPILER_DEPENDENT_UINT64 long long
#include "actypes.h"
#include "actbl.h"
/*
* Detect ACPI and export information about the APCI BIOS into the
* environment.
*/
static RSDP_DESCRIPTOR *biosacpi_find_rsdp(void);
static RSDP_DESCRIPTOR *biosacpi_search_rsdp(char *base, int length);
#define RSDP_CHECKSUM_LENGTH 20
void
biosacpi_detect(void)
{
RSDP_DESCRIPTOR *rsdp;
char buf[16];
int revision;
/* XXX check the BIOS datestamp */
/* locate and validate the RSDP */
if ((rsdp = biosacpi_find_rsdp()) == NULL)
return;
/* export values from the RSDP */
revision = rsdp->Revision;
if (revision == 0)
revision = 1;
sprintf(buf, "%d", revision);
setenv("hint.acpi.0.revision", buf, 1);
sprintf(buf, "%6s", rsdp->OemId);
setenv("hint.acpi.0.oem", buf, 1);
sprintf(buf, "0x%08x", rsdp->RsdtPhysicalAddress);
setenv("hint.acpi.0.rsdt", buf, 1);
if (revision >= 2) {
/* XXX extended checksum? */
sprintf(buf, "0x%016llx", rsdp->XsdtPhysicalAddress);
setenv("hint.acpi.0.xsdt", buf, 1);
sprintf(buf, "%d", rsdp->Length);
setenv("hint.acpi.0.xsdt_length", buf, 1);
}
/* XXX other tables? */
setenv("acpi_load", "YES", 1);
}
/*
* Find the RSDP in low memory.
*/
static RSDP_DESCRIPTOR *
biosacpi_find_rsdp(void)
{
RSDP_DESCRIPTOR *rsdp;
/* search the EBDA */
if ((rsdp = biosacpi_search_rsdp((char *)0, 0x400)) != NULL)
return(rsdp);
/* search the BIOS space */
if ((rsdp = biosacpi_search_rsdp((char *)0xe0000, 0x20000)) != NULL)
return(rsdp);
return(NULL);
}
static RSDP_DESCRIPTOR *
biosacpi_search_rsdp(char *base, int length)
{
RSDP_DESCRIPTOR *rsdp;
u_int8_t *cp, sum;
int ofs, idx;
/* search on 16-byte boundaries */
for (ofs = 0; ofs < length; ofs += 16) {
rsdp = (RSDP_DESCRIPTOR *)(base + ofs);
/* compare signature, validate checksum */
if (!strncmp(rsdp->Signature, RSDP_SIG, strlen(RSDP_SIG))) {
cp = (u_int8_t *)rsdp;
sum = 0;
for (idx = 0; idx < RSDP_CHECKSUM_LENGTH; idx++)
sum += *(cp + idx);
if (sum != 0) {
printf("acpi: bad RSDP checksum (%d)\n", sum);
continue;
}
return(rsdp);
}
}
return(NULL);
}