o Use sysctl machdep.acpi_root to get the physical address of the

   RSDP. Scan the first 1MB on i386 if the sysctl fails,
o  Extend struct ACPIrsdp with the ACPI 2.0 fields which involves
   changing a prior reserved field into the ACPI revision,
o  Only calculate the RSDP checksum on the first 20 bytes to remain
   compatible with ACPI 1.0 tables; we don't check the extended
   checksum covering the whole table,
o  Use the length field in the RSDP to map the RSDP into the address
   space so that we don't have to know about future extensions here.

4 files changed, 42 insertions, 17 deletions

diff --git a/usr.sbin/acpi/acpidump/acpi.c b/usr.sbin/acpi/acpidump/acpi.c
index da5c386..daba8a2 100644
--- a/usr.sbin/acpi/acpidump/acpi.c
+++ b/usr.sbin/acpi/acpidump/acpi.c
@@ -327,7 +327,7 @@ acpi_print_rsd_ptr(struct ACPIrsdp *rp)
 	printf(BEGIN_COMMENT);
 	printf("RSD PTR: Checksum=%d, OEMID=", rp->sum);
 	acpi_print_string(rp->oem, 6);
-	printf(", RsdtAddress=0x%08x\n", rp->addr);
+	printf(", RsdtAddress=0x%08x\n", rp->rsdt_addr);
 	printf(END_COMMENT);
 }
 
diff --git a/usr.sbin/acpi/acpidump/acpi_user.c b/usr.sbin/acpi/acpidump/acpi_user.c
index c6a8d99..8361ef6 100644
--- a/usr.sbin/acpi/acpidump/acpi_user.c
+++ b/usr.sbin/acpi/acpidump/acpi_user.c
@@ -41,6 +41,8 @@
 
 #include "acpidump.h"
 
+static char machdep_acpi_root[] = "machdep.acpi_root";
+
 static int      acpi_mem_fd = -1;
 
 struct acpi_user_mapping {
@@ -98,22 +100,41 @@ acpi_user_find_mapping(vm_offset_t pa, size_t size)
 struct ACPIrsdp *
 acpi_find_rsd_ptr()
 {
-	int		i;
-	u_int8_t	buf[sizeof(struct ACPIrsdp)];
+	struct ACPIrsdp rsdp;
+	u_long		addr;
+	int		len;
 
 	acpi_user_init();
-	for (i = 0; i < 1024 * 1024; i += 16) {
-		read(acpi_mem_fd, buf, 16);
-		if (!memcmp(buf, "RSD PTR ", 8)) {
-			/* Read the rest of the structure */
-			read(acpi_mem_fd, buf + 16, sizeof(struct ACPIrsdp) - 16);
-
-			/* Verify checksum before accepting it. */
-			if (acpi_checksum(buf, sizeof(struct ACPIrsdp)))
-				continue;
-			return (acpi_map_physical(i, sizeof(struct ACPIrsdp)));
-		}
+
+	len = sizeof(addr);
+	if (sysctlbyname(machdep_acpi_root, &addr, &len, NULL, 0) == 0) {	
+		pread(acpi_mem_fd, &rsdp, sizeof(rsdp), addr);
+		if (memcmp(rsdp.signature, "RSD PTR ", 8))
+			errx(1, "sysctl %s does not point to RSDP\n",
+			    machdep_acpi_root);
+		len = 20;			/* size of ACPI 1.0 table */
+		if (acpi_checksum(&rsdp, len))
+			warnx("RSDP has invalid checksum\n");
+		if (rsdp.revision > 0)
+			len = rsdp.length;
+		return (acpi_map_physical(addr, len));
+	}
+
+#if !defined(__ia64__)
+	for (addr = 0UL; addr < 1024UL * 1024UL; addr += 16UL) {
+		pread(acpi_mem_fd, &rsdp, 8, addr);
+		if (memcmp(rsdp.signature, "RSD PTR ", 8))
+			continue;
+		/* Read the entire table. */
+		pread(acpi_mem_fd, &rsdp, sizeof(rsdp), addr);
+		len = 20;			/* size of ACPI 1.0 table */
+		if (acpi_checksum(&rsdp, len))
+			continue;
+		if (rsdp.revision > 0)
+			len = rsdp.length;
+		return (acpi_map_physical(addr, len));
 	}
+#endif
 
 	return (0);
 }
diff --git a/usr.sbin/acpi/acpidump/acpidump.c b/usr.sbin/acpi/acpidump/acpidump.c
index a687568..df6ce1f6 100644
--- a/usr.sbin/acpi/acpidump/acpidump.c
+++ b/usr.sbin/acpi/acpidump/acpidump.c
@@ -58,7 +58,7 @@ asl_dump_from_devmem()
 		errx(1, "Can't find ACPI information\n");
 
 	acpi_print_rsd_ptr(rp);
-	rsdp = (struct ACPIsdt *) acpi_map_sdt(rp->addr);
+	rsdp = (struct ACPIsdt *) acpi_map_sdt(rp->rsdt_addr);
 	if (memcmp(rsdp->signature, "RSDT", 4) ||
 	    acpi_checksum(rsdp, rsdp->len))
 		errx(1, "RSDT is corrupted\n");
diff --git a/usr.sbin/acpi/acpidump/acpidump.h b/usr.sbin/acpi/acpidump/acpidump.h
index 796246e..49d28ef 100644
--- a/usr.sbin/acpi/acpidump/acpidump.h
+++ b/usr.sbin/acpi/acpidump/acpidump.h
@@ -51,8 +51,12 @@ struct ACPIrsdp {
 	u_char		signature[8];
 	u_char		sum;
 	u_char		oem[6];
-	u_char		res;
-	u_int32_t	addr;
+	u_char		revision;
+	u_int32_t	rsdt_addr;
+	u_int32_t	length;
+	u_int64_t	xsdt_addr;
+	u_char		xsum;
+	u_char		_reserved_[3];
 } __packed;
 
 /* System Description Table */