diff --git a/sys/x86/acpica/OsdEnvironment.c b/sys/x86/acpica/OsdEnvironment.c
--- a/sys/x86/acpica/OsdEnvironment.c
+++ b/sys/x86/acpica/OsdEnvironment.c
@@ -77,14 +77,22 @@
 	return (0);
 }
 
+void
+acpi_set_root(vm_paddr_t addr)
+{
+
+	KASSERT(acpi_root_phys == 0, ("ACPI root pointer already set"));
+	acpi_root_phys = addr;
+}
+
 ACPI_PHYSICAL_ADDRESS
 AcpiOsGetRootPointer(void)
 {
 
 	if (acpi_root_phys == 0) {
-		acpi_root_phys = acpi_get_root_from_loader();
+		acpi_set_root(acpi_get_root_from_loader());
 		if (acpi_root_phys == 0)
-			acpi_root_phys = acpi_get_root_from_memory();
+			acpi_set_root(acpi_get_root_from_memory());
 	}
 
 	return (acpi_root_phys);
diff --git a/sys/x86/include/acpica_machdep.h b/sys/x86/include/acpica_machdep.h
--- a/sys/x86/include/acpica_machdep.h
+++ b/sys/x86/include/acpica_machdep.h
@@ -84,6 +84,8 @@
 extern int madt_found_sci_override;
 extern int (*apei_nmi)(void);
 
+void	acpi_set_root(vm_paddr_t addr);
+
 #endif /* _KERNEL */
 
 #endif /* __ACPICA_MACHDEP_H__ */
diff --git a/sys/x86/xen/pv.c b/sys/x86/xen/pv.c
--- a/sys/x86/xen/pv.c
+++ b/sys/x86/xen/pv.c
@@ -60,6 +60,7 @@
 
 #include <machine/_inttypes.h>
 #include <machine/intr_machdep.h>
+#include <x86/acpica_machdep.h>
 #include <x86/apicvar.h>
 #include <x86/init.h>
 #include <machine/pc/bios.h>
@@ -157,7 +158,6 @@
 {
 	struct hvm_modlist_entry *mod;
 	uint64_t physfree;
-	char *kenv;
 
 	start_info = (struct hvm_start_info *)(start_info_paddr + KERNBASE);
 	if (start_info->magic != XEN_HVM_START_MAGIC_VALUE) {
@@ -196,15 +196,6 @@
 			    PAGE_SIZE), physfree);
 	}
 
-	/*
-	 * Init a static kenv using a free page. The contents will be filled
-	 * from the parse_preload_data hook.
-	 */
-	kenv = (void *)(physfree + KERNBASE);
-	physfree += PAGE_SIZE;
-	bzero_early(kenv, PAGE_SIZE);
-	init_static_kenv(kenv, PAGE_SIZE);
-
 	/* Set the hooks for early functions that diverge from bare metal */
 	init_ops = xen_pvh_init_ops;
 	hvm_start_flags = start_info->flags;
@@ -215,52 +206,6 @@
 
 /*-------------------------------- PV specific -------------------------------*/
 
-/*
- * When booted as a PVH guest FreeBSD needs to avoid using the RSDP address
- * hint provided by the loader because it points to the native set of ACPI
- * tables instead of the ones crafted by Xen. The acpi.rsdp env variable is
- * removed from kenv if present, and a new acpi.rsdp is added to kenv that
- * points to the address of the Xen crafted RSDP.
- */
-static bool reject_option(const char *option)
-{
-	static const char *reject[] = {
-		"acpi.rsdp",
-	};
-	unsigned int i;
-
-	for (i = 0; i < nitems(reject); i++)
-		if (strncmp(option, reject[i], strlen(reject[i])) == 0)
-			return (true);
-
-	return (false);
-}
-
-static void
-xen_pvh_set_env(char *env, bool (*filter)(const char *))
-{
-	char *option;
-
-	if (env == NULL)
-		return;
-
-	option = env;
-	while (*option != 0) {
-		char *value;
-
-		if (filter != NULL && filter(option)) {
-			option += strlen(option) + 1;
-			continue;
-		}
-
-		value = option;
-		option = strsep(&value, "=");
-		if (kern_setenv(option, value) != 0 && isxen())
-			xc_printf("unable to add kenv %s=%s\n", option, value);
-		option = value + strlen(value) + 1;
-	}
-}
-
 #ifdef DDB
 /*
  * The way Xen loads the symtab is different from the native boot loader,
@@ -313,7 +258,6 @@
 	vm_ooffset_t off;
 	vm_paddr_t metadata;
 	char *envp;
-	char acpi_rsdp[19];
 
 	TSENTER();
 	if (start_info->modlist_paddr != 0) {
@@ -379,13 +323,18 @@
 		envp = MD_FETCH(kmdp, MODINFOMD_ENVP, char *);
 		if (envp != NULL)
 			envp += off;
-		xen_pvh_set_env(envp, reject_option);
+		init_static_kenv(envp, 0);
 
 		if (MD_FETCH(kmdp, MODINFOMD_EFI_MAP, void *) != NULL)
 		    strlcpy(bootmethod, "UEFI", sizeof(bootmethod));
 		else
 		    strlcpy(bootmethod, "BIOS", sizeof(bootmethod));
 	} else {
+		static char kenv_buffer[PAGE_SIZE];
+
+		/* Provide a static kenv so the command line can be parsed. */
+		init_static_kenv(kenv_buffer, sizeof(kenv_buffer));
+
 		/* Parse the extra boot information given by Xen */
 		if (start_info->cmdline_paddr != 0)
 			boot_parse_cmdline_delim(
@@ -397,9 +346,12 @@
 
 	boothowto |= boot_env_to_howto();
 
-	snprintf(acpi_rsdp, sizeof(acpi_rsdp), "%#" PRIx64,
-	    start_info->rsdp_paddr);
-	kern_setenv("acpi.rsdp", acpi_rsdp);
+	/*
+	 * When booted as a PVH guest FreeBSD must not use the RSDP address
+	 * hint provided by the loader because it points to the native set of
+	 * ACPI tables instead of the ones crafted by Xen.
+	 */
+	acpi_set_root(start_info->rsdp_paddr);
 
 #ifdef DDB
 	xen_pvh_parse_symtab();