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.

1 files changed, 126 insertions, 0 deletions

diff --git a/sys/boot/i386/libi386/biosacpi.c b/sys/boot/i386/libi386/biosacpi.c
new file mode 100644
index 0000000..343f407
--- /dev/null
+++ b/sys/boot/i386/libi386/biosacpi.c
@@ -0,0 +1,126 @@
+/*-
+ * 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);
+}