Implement RootPathString support in the LoadTable() AML function. Fixes

booting OpenBSD on some (ancient?) Hyper-V version.

Tested by Henryk Paluch
ok mlarkin@

3 files changed, 22 insertions, 15 deletions

diff --git a/sys/dev/acpi/acpi.c b/sys/dev/acpi/acpi.c
index ba6a3c468a4..70b67bb8fa7 100644
--- a/sys/dev/acpi/acpi.c
+++ b/sys/dev/acpi/acpi.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: acpi.c,v 1.425 2023/07/08 08:01:10 tobhe Exp $ */
+/* $OpenBSD: acpi.c,v 1.426 2024/01/08 19:52:29 kettenis Exp $ */
 /*
  * Copyright (c) 2005 Thorsten Lockert <tholo@sigmasoft.com>
  * Copyright (c) 2005 Jordan Hargrave <jordan@openbsd.org>
@@ -1104,16 +1104,16 @@ acpi_attach_common(struct acpi_softc *sc, paddr_t base)
 		printf(" !DSDT");
 
 	p_dsdt = entry->q_table;
-	acpi_parse_aml(sc, p_dsdt->aml, p_dsdt->hdr_length -
-	    sizeof(p_dsdt->hdr));
+	acpi_parse_aml(sc, NULL, p_dsdt->aml,
+	    p_dsdt->hdr_length - sizeof(p_dsdt->hdr));
 
 	/* Load SSDT's */
 	SIMPLEQ_FOREACH(entry, &sc->sc_tables, q_next) {
 		if (memcmp(entry->q_table, SSDT_SIG,
 		    sizeof(SSDT_SIG) - 1) == 0) {
 			p_dsdt = entry->q_table;
-			acpi_parse_aml(sc, p_dsdt->aml, p_dsdt->hdr_length -
-			    sizeof(p_dsdt->hdr));
+			acpi_parse_aml(sc, NULL, p_dsdt->aml,
+			    p_dsdt->hdr_length - sizeof(p_dsdt->hdr));
 		}
 	}
 
diff --git a/sys/dev/acpi/dsdt.c b/sys/dev/acpi/dsdt.c
index 1a5694c9e4b..24ebf445551 100644
--- a/sys/dev/acpi/dsdt.c
+++ b/sys/dev/acpi/dsdt.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: dsdt.c,v 1.264 2021/12/09 20:21:35 patrick Exp $ */
+/* $OpenBSD: dsdt.c,v 1.265 2024/01/08 19:52:29 kettenis Exp $ */
 /*
  * Copyright (c) 2005 Jordan Hargrave <jordan@openbsd.org>
  *
@@ -634,8 +634,9 @@ __aml_search(struct aml_node *root, uint8_t *nameseg, int create)
 
 		SIMPLEQ_INIT(&node->son);
 		SIMPLEQ_INSERT_TAIL(&root->son, node, sib);
+		return node;
 	}
-	return node;
+	return NULL;
 }
 
 /* Get absolute pathname of AML node */
@@ -3742,8 +3743,6 @@ aml_loadtable(struct acpi_softc *sc, const char *signature,
 	struct acpi_dsdt *p_dsdt;
 	struct acpi_q *entry;
 
-	if (strlen(rootpath) > 0)
-		aml_die("LoadTable: RootPathString unsupported");
 	if (strlen(parameterpath) > 0)
 		aml_die("LoadTable: ParameterPathString unsupported");
 
@@ -3755,8 +3754,8 @@ aml_loadtable(struct acpi_softc *sc, const char *signature,
 		    strncmp(hdr->oemtableid, oemtableid,
 		    sizeof(hdr->oemtableid)) == 0) {
 			p_dsdt = entry->q_table;
-			acpi_parse_aml(sc, p_dsdt->aml, p_dsdt->hdr_length -
-			    sizeof(p_dsdt->hdr));
+			acpi_parse_aml(sc, rootpath, p_dsdt->aml,
+			    p_dsdt->hdr_length - sizeof(p_dsdt->hdr));
 			return aml_allocvalue(AML_OBJTYPE_DDBHANDLE, 0, 0);
 		}
 	}
@@ -4520,11 +4519,19 @@ parse_error:
 }
 
 int
-acpi_parse_aml(struct acpi_softc *sc, uint8_t *start, uint32_t length)
+acpi_parse_aml(struct acpi_softc *sc, const char *rootpath,
+    uint8_t *start, uint32_t length)
 {
+	struct aml_node *root = &aml_root;
 	struct aml_scope *scope;
 	struct aml_value res;
 
+	if (rootpath) {
+		root = aml_searchname(&aml_root, rootpath);
+		if (root == NULL)
+			aml_die("Invalid RootPathName %s\n", rootpath);
+	}
+
 	aml_root.start = start;
 	memset(&res, 0, sizeof(res));
 	res.type = AML_OBJTYPE_SCOPE;
diff --git a/sys/dev/acpi/dsdt.h b/sys/dev/acpi/dsdt.h
index 41633ced748..f63d8b4ac91 100644
--- a/sys/dev/acpi/dsdt.h
+++ b/sys/dev/acpi/dsdt.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: dsdt.h,v 1.80 2023/04/02 11:32:48 jsg Exp $ */
+/* $OpenBSD: dsdt.h,v 1.81 2024/01/08 19:52:29 kettenis Exp $ */
 /*
  * Copyright (c) 2005 Marco Peereboom <marco@openbsd.org>
  *
@@ -56,8 +56,8 @@ void			aml_walktree(struct aml_node *);
 
 void			aml_find_node(struct aml_node *, const char *,
 			    int (*)(struct aml_node *, void *), void *);
-int			acpi_parse_aml(struct acpi_softc *, u_int8_t *,
-			    uint32_t);
+int			acpi_parse_aml(struct acpi_softc *, const char *,
+			    u_int8_t *, uint32_t);
 void			aml_register_notify(struct aml_node *, const char *,
 			    int (*)(struct aml_node *, int, void *), void *,
 			    int);