diff mbox

[1/2] acpi: Add support for STAO Table (LP: #1478957)

Message ID 1438176000-14024-2-git-send-email-colin.king@canonical.com
State Accepted
Headers show

Commit Message

Colin Ian King July 29, 2015, 1:19 p.m. UTC 
From: Colin Ian King <colin.king@canonical.com>

Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 src/Makefile.am             |   5 +-
 src/acpi/stao/stao.c        | 219 ++++++++++++++++++++++++++++++++++++++++++++
 src/lib/include/fwts_acpi.h |  10 ++
 3 files changed, 232 insertions(+), 2 deletions(-)
 create mode 100644 src/acpi/stao/stao.c

Comments

Ivan Hu Aug. 3, 2015, 2:39 a.m. UTC | #1 
On 2015年07月29日 21:19, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
>
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
>   src/Makefile.am             |   5 +-
>   src/acpi/stao/stao.c        | 219 ++++++++++++++++++++++++++++++++++++++++++++
>   src/lib/include/fwts_acpi.h |  10 ++
>   3 files changed, 232 insertions(+), 2 deletions(-)
>   create mode 100644 src/acpi/stao/stao.c
>
> diff --git a/src/Makefile.am b/src/Makefile.am
> index 6821216..e9b7180 100644
> --- a/src/Makefile.am
> +++ b/src/Makefile.am
> @@ -77,10 +77,11 @@ fwts_SOURCES = main.c 				\
>   	acpi/slit/slit.c 			\
>   	acpi/spcr/spcr.c 			\
>   	acpi/spmi/spmi.c 			\
> -	acpi/tcpa/tcpa.c 			\
> -	acpi/tpm2/tpm2.c 			\
>   	acpi/srat/srat.c 			\
> +	acpi/stao/stao.c			\
>   	acpi/syntaxcheck/syntaxcheck.c 		\
> +	acpi/tcpa/tcpa.c 			\
> +	acpi/tpm2/tpm2.c 			\
>   	acpi/uefi/uefi.c			\
>   	acpi/waet/waet.c			\
>   	acpi/wakealarm/wakealarm.c 		\
> diff --git a/src/acpi/stao/stao.c b/src/acpi/stao/stao.c
> new file mode 100644
> index 0000000..b0243d0
> --- /dev/null
> +++ b/src/acpi/stao/stao.c
> @@ -0,0 +1,219 @@
> +/*
> + * Copyright (C) 2015 Canonical
> + *
> + * Portions of this code original from the Linux-ready Firmware Developer Kit
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * as published by the Free Software Foundation; either version 2
> + * of the License, or (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
> + *
> + */
> +#include "fwts.h"
> +
> +#include <stdlib.h>
> +#include <stdio.h>
> +#include <unistd.h>
> +#include <inttypes.h>
> +#include <string.h>
> +
> +#include "fwts_acpi_object_eval.h"
> +
> +static fwts_acpi_table_info *table;
> +
> +static int stao_init(fwts_framework *fw)
> +{
> +
> +	if (fwts_acpi_find_table(fw, "STAO", 0, &table) != FWTS_OK) {
> +		fwts_log_error(fw, "Cannot read ACPI tables.");
> +		return FWTS_ERROR;
> +	}
> +	if (table == NULL || (table && table->length == 0)) {
> +		fwts_log_error(fw, "ACPI STAO table does not exist, skipping test");
> +		return FWTS_SKIP;
> +	}
> +
> +	return FWTS_OK;
> +}
> +
> +/*
> + *  Extract a STAO ACPI String from the raw buffer
> + */
> +static bool stao_acpi_string(
> +	fwts_framework *fw,
> +	char *str,
> +	char *end,
> +	bool *passed,
> +	size_t *len)
> +{
> +	char *ptr = str;
> +
> +	while (*ptr) {
> +		if (ptr > end) {
> +			*passed = false;
> +			fwts_failed(fw, LOG_LEVEL_HIGH,
> +				"STAOAcpiStringNotNullTerminated",
> +				"STAO ACPI String has reached the end of the "
> +				"ACPI table and did not have a 0x00 string "
> +				"terminator");
> +			*len = 0;
> +			return false;
> +		}
> +		ptr++;
> +	}
> +	*len = ptr - str;
> +	return true;
> +}
> +
> +/*
> + *  STAO Status Override Table
> + *    http://wiki.xenproject.org/mediawiki/images/0/02/Status-override-table.pdf
> + */
> +static int stao_test1(fwts_framework *fw)
> +{
> +	const fwts_acpi_table_stao *stao = (const fwts_acpi_table_stao *)table->data;
> +	bool passed = true;
> +	char *ptr, *end;
> +	fwts_list_link  *item;
> +	fwts_list *objects;
> +	int i = -1, strings = 0;
> +	char *ptr1, *ptr2;
> +	char *expanded;
> +
> +	if (stao->header.length > (uint32_t)table->length) {
> +		passed = false;
> +		fwts_failed(fw, LOG_LEVEL_MEDIUM,
> +			"STAOBadLength",
> +			"STAO header reports that the table is %" PRIu32
> +			" bytes long, however this is longer than the ACPI "
> +			"table size of %zu bytes.",
> +			stao->header.length,
> +			table->length);
> +		goto done;
> +	}
> +
> +	/* Now we have got some sane data, dump the STAO */
> +        fwts_log_info_verbatum(fw, "STAO Status Override Table:");
> +        fwts_log_info_verbatum(fw, "  UART:                     0x%2.2" PRIx8, stao->uart);
> +
> +	ptr = (char *)stao->namelist;
> +	end = (char *)table->data + stao->header.length;
> +
> +	while (ptr < end) {
> +		size_t len;
> +
> +		if (!stao_acpi_string(fw, ptr, end, &passed, &len))
> +			break;
> +
> +		fwts_log_info_verbatum(fw, "  ACPI String:              '%s'", ptr);
> +		strings++;
> +		/*  String length + null byte */
> +		ptr += len + 1;
> +	}
> +	if (!strings)
> +		goto done;
> +
> +        if (fwts_acpi_init(fw) != FWTS_OK) {
> +		fwts_log_error(fw, "Cannot initialise ACPI, skipping ACPI string check");
> +		goto done;
> +	}
> +	if ((objects = fwts_acpi_object_get_names()) == NULL) {
> +		fwts_log_info(fw, "Cannot find any ACPI objects");
> +		fwts_acpi_deinit(fw);
> +		goto deinit;
> +	}
> +	ptr = (char *)stao->namelist;
> +	end = (char *)table->data + table->length;
> +
> +	while (ptr < end) {
> +		bool not_found = true;
> +		size_t len;
> +
> +		if (!stao_acpi_string(fw, ptr, end, &passed, &len))
> +			break;
> +
> +		/* Find number of '.' in object path */
> +		for (i = 0, ptr1 = ptr; *ptr1; ptr1++) {
> +			if (*ptr1 == '.')
> +				i++;
> +		}
> +
> +		/*
> +		 *  Allocate buffer big enough to take expanded path
> +		 *  and pad out any fields that are not 4 chars in size
> +		 *  between each . separator
> +		 *
> +		 *  Converts \_SB.A.BB.CCC.DDDD.EE to
> +		 *	     \_SB_.A___.BB__.CCC_.DDDD.EE__
> +		 */
> +		expanded = malloc(1 + (5 * (i + 1)));
> +		if (!expanded) {
> +			fwts_log_error(fw, "Cannot allocate temporary ACPI string buffer");
> +			goto deinit;
> +		}
> +
> +		for (i = -1, ptr1 = ptr, ptr2 = expanded; ; ptr1++) {
> +			if (*ptr1 == '.' || *ptr1 == '\0') {
> +				while (i < 4) {
> +					*ptr2++ = '_';
> +					i++;
> +				}
> +				i = 0;
> +			} else {
> +				i++;
> +			}
> +			*ptr2++ = *ptr1;
> +			if (!*ptr1)
> +				break;
> +		}
> +
> +		/* Search for object */
> +		fwts_list_foreach(item, objects) {
> +			char *name = fwts_list_data(char *, item);
> +			if (!strcmp(expanded, name)) {
> +				not_found = false;
> +				break;
> +			}
> +		}
> +
> +		if (not_found) {
> +			passed = false;
> +			fwts_failed(fw, LOG_LEVEL_HIGH,
> +				"STAOAcpiStringNotFound",
> +				"STAO ACPI String '%s' not found in ACPI object name space.",
> +				expanded);
> +		}
> +		free(expanded);
> +		ptr += len + 1;
> +	}
> +
> +deinit:
> +	fwts_acpi_deinit(fw);
> +done:
> +	if (passed)
> +		fwts_passed(fw, "No issues found in STAO table.");
> +
> +	return FWTS_OK;
> +}
> +
> +static fwts_framework_minor_test stao_tests[] = {
> +	{ stao_test1, "STAO Status Override Table test." },
> +	{ NULL, NULL }
> +};
> +
> +static fwts_framework_ops stao_ops = {
> +	.description = "STAO Status Override Table test.",
> +	.init        = stao_init,
> +	.minor_tests = stao_tests
> +};
> +
> +FWTS_REGISTER("stao", &stao_ops, FWTS_TEST_ANYTIME, FWTS_FLAG_BATCH | FWTS_FLAG_TEST_ACPI)
> diff --git a/src/lib/include/fwts_acpi.h b/src/lib/include/fwts_acpi.h
> index b4a4ba2..4ee8cb2 100644
> --- a/src/lib/include/fwts_acpi.h
> +++ b/src/lib/include/fwts_acpi.h
> @@ -1270,4 +1270,14 @@ typedef struct {
>   	*/
>   } __attribute__ ((packed)) fwts_acpi_table_iort_pci_root_complex_node;
>   
> +/*
> + *  STAO Status Override Table
> + *    http://wiki.xenproject.org/mediawiki/images/0/02/Status-override-table.pdf
> + */
> +typedef struct {
> +	fwts_acpi_table_header  header;
> +	uint8_t		uart;
> +	uint8_t		namelist[0];
> +} __attribute__ ((packed)) fwts_acpi_table_stao;
> +
>   #endif
Acked-by: Ivan Hu<ivan.hu@canonical.com>
Alex Hung Aug. 4, 2015, 2:20 a.m. UTC | #2 
On 07/29/2015 09:19 PM, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
> 
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
>  src/Makefile.am             |   5 +-
>  src/acpi/stao/stao.c        | 219 ++++++++++++++++++++++++++++++++++++++++++++
>  src/lib/include/fwts_acpi.h |  10 ++
>  3 files changed, 232 insertions(+), 2 deletions(-)
>  create mode 100644 src/acpi/stao/stao.c
> 
> diff --git a/src/Makefile.am b/src/Makefile.am
> index 6821216..e9b7180 100644
> --- a/src/Makefile.am
> +++ b/src/Makefile.am
> @@ -77,10 +77,11 @@ fwts_SOURCES = main.c 				\
>  	acpi/slit/slit.c 			\
>  	acpi/spcr/spcr.c 			\
>  	acpi/spmi/spmi.c 			\
> -	acpi/tcpa/tcpa.c 			\
> -	acpi/tpm2/tpm2.c 			\
>  	acpi/srat/srat.c 			\
> +	acpi/stao/stao.c			\
>  	acpi/syntaxcheck/syntaxcheck.c 		\
> +	acpi/tcpa/tcpa.c 			\
> +	acpi/tpm2/tpm2.c 			\
>  	acpi/uefi/uefi.c			\
>  	acpi/waet/waet.c			\
>  	acpi/wakealarm/wakealarm.c 		\
> diff --git a/src/acpi/stao/stao.c b/src/acpi/stao/stao.c
> new file mode 100644
> index 0000000..b0243d0
> --- /dev/null
> +++ b/src/acpi/stao/stao.c
> @@ -0,0 +1,219 @@
> +/*
> + * Copyright (C) 2015 Canonical
> + *
> + * Portions of this code original from the Linux-ready Firmware Developer Kit
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * as published by the Free Software Foundation; either version 2
> + * of the License, or (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
> + *
> + */
> +#include "fwts.h"
> +
> +#include <stdlib.h>
> +#include <stdio.h>
> +#include <unistd.h>
> +#include <inttypes.h>
> +#include <string.h>
> +
> +#include "fwts_acpi_object_eval.h"
> +
> +static fwts_acpi_table_info *table;
> +
> +static int stao_init(fwts_framework *fw)
> +{
> +
> +	if (fwts_acpi_find_table(fw, "STAO", 0, &table) != FWTS_OK) {
> +		fwts_log_error(fw, "Cannot read ACPI tables.");
> +		return FWTS_ERROR;
> +	}
> +	if (table == NULL || (table && table->length == 0)) {
> +		fwts_log_error(fw, "ACPI STAO table does not exist, skipping test");
> +		return FWTS_SKIP;
> +	}
> +
> +	return FWTS_OK;
> +}
> +
> +/*
> + *  Extract a STAO ACPI String from the raw buffer
> + */
> +static bool stao_acpi_string(
> +	fwts_framework *fw,
> +	char *str,
> +	char *end,
> +	bool *passed,
> +	size_t *len)
> +{
> +	char *ptr = str;
> +
> +	while (*ptr) {
> +		if (ptr > end) {
> +			*passed = false;
> +			fwts_failed(fw, LOG_LEVEL_HIGH,
> +				"STAOAcpiStringNotNullTerminated",
> +				"STAO ACPI String has reached the end of the "
> +				"ACPI table and did not have a 0x00 string "
> +				"terminator");
> +			*len = 0;
> +			return false;
> +		}
> +		ptr++;
> +	}
> +	*len = ptr - str;
> +	return true;
> +}
> +
> +/*
> + *  STAO Status Override Table
> + *    http://wiki.xenproject.org/mediawiki/images/0/02/Status-override-table.pdf
> + */
> +static int stao_test1(fwts_framework *fw)
> +{
> +	const fwts_acpi_table_stao *stao = (const fwts_acpi_table_stao *)table->data;
> +	bool passed = true;
> +	char *ptr, *end;
> +	fwts_list_link  *item;
> +	fwts_list *objects;
> +	int i = -1, strings = 0;
> +	char *ptr1, *ptr2;
> +	char *expanded;
> +
> +	if (stao->header.length > (uint32_t)table->length) {
> +		passed = false;
> +		fwts_failed(fw, LOG_LEVEL_MEDIUM,
> +			"STAOBadLength",
> +			"STAO header reports that the table is %" PRIu32
> +			" bytes long, however this is longer than the ACPI "
> +			"table size of %zu bytes.",
> +			stao->header.length,
> +			table->length);
> +		goto done;
> +	}
> +
> +	/* Now we have got some sane data, dump the STAO */
> +        fwts_log_info_verbatum(fw, "STAO Status Override Table:");
> +        fwts_log_info_verbatum(fw, "  UART:                     0x%2.2" PRIx8, stao->uart);
> +
> +	ptr = (char *)stao->namelist;
> +	end = (char *)table->data + stao->header.length;
> +
> +	while (ptr < end) {
> +		size_t len;
> +
> +		if (!stao_acpi_string(fw, ptr, end, &passed, &len))
> +			break;
> +
> +		fwts_log_info_verbatum(fw, "  ACPI String:              '%s'", ptr);
> +		strings++;
> +		/*  String length + null byte */
> +		ptr += len + 1;
> +	}
> +	if (!strings)
> +		goto done;
> +
> +        if (fwts_acpi_init(fw) != FWTS_OK) {
> +		fwts_log_error(fw, "Cannot initialise ACPI, skipping ACPI string check");
> +		goto done;
> +	}
> +	if ((objects = fwts_acpi_object_get_names()) == NULL) {
> +		fwts_log_info(fw, "Cannot find any ACPI objects");
> +		fwts_acpi_deinit(fw);
> +		goto deinit;
> +	}
> +	ptr = (char *)stao->namelist;
> +	end = (char *)table->data + table->length;
> +
> +	while (ptr < end) {
> +		bool not_found = true;
> +		size_t len;
> +
> +		if (!stao_acpi_string(fw, ptr, end, &passed, &len))
> +			break;
> +
> +		/* Find number of '.' in object path */
> +		for (i = 0, ptr1 = ptr; *ptr1; ptr1++) {
> +			if (*ptr1 == '.')
> +				i++;
> +		}
> +
> +		/*
> +		 *  Allocate buffer big enough to take expanded path
> +		 *  and pad out any fields that are not 4 chars in size
> +		 *  between each . separator
> +		 *
> +		 *  Converts \_SB.A.BB.CCC.DDDD.EE to
> +		 *	     \_SB_.A___.BB__.CCC_.DDDD.EE__
> +		 */
> +		expanded = malloc(1 + (5 * (i + 1)));
> +		if (!expanded) {
> +			fwts_log_error(fw, "Cannot allocate temporary ACPI string buffer");
> +			goto deinit;
> +		}
> +
> +		for (i = -1, ptr1 = ptr, ptr2 = expanded; ; ptr1++) {
> +			if (*ptr1 == '.' || *ptr1 == '\0') {
> +				while (i < 4) {
> +					*ptr2++ = '_';
> +					i++;
> +				}
> +				i = 0;
> +			} else {
> +				i++;
> +			}
> +			*ptr2++ = *ptr1;
> +			if (!*ptr1)
> +				break;
> +		}
> +
> +		/* Search for object */
> +		fwts_list_foreach(item, objects) {
> +			char *name = fwts_list_data(char *, item);
> +			if (!strcmp(expanded, name)) {
> +				not_found = false;
> +				break;
> +			}
> +		}
> +
> +		if (not_found) {
> +			passed = false;
> +			fwts_failed(fw, LOG_LEVEL_HIGH,
> +				"STAOAcpiStringNotFound",
> +				"STAO ACPI String '%s' not found in ACPI object name space.",
> +				expanded);
> +		}
> +		free(expanded);
> +		ptr += len + 1;
> +	}
> +
> +deinit:
> +	fwts_acpi_deinit(fw);
> +done:
> +	if (passed)
> +		fwts_passed(fw, "No issues found in STAO table.");
> +
> +	return FWTS_OK;
> +}
> +
> +static fwts_framework_minor_test stao_tests[] = {
> +	{ stao_test1, "STAO Status Override Table test." },
> +	{ NULL, NULL }
> +};
> +
> +static fwts_framework_ops stao_ops = {
> +	.description = "STAO Status Override Table test.",
> +	.init        = stao_init,
> +	.minor_tests = stao_tests
> +};
> +
> +FWTS_REGISTER("stao", &stao_ops, FWTS_TEST_ANYTIME, FWTS_FLAG_BATCH | FWTS_FLAG_TEST_ACPI)
> diff --git a/src/lib/include/fwts_acpi.h b/src/lib/include/fwts_acpi.h
> index b4a4ba2..4ee8cb2 100644
> --- a/src/lib/include/fwts_acpi.h
> +++ b/src/lib/include/fwts_acpi.h
> @@ -1270,4 +1270,14 @@ typedef struct {
>  	*/
>  } __attribute__ ((packed)) fwts_acpi_table_iort_pci_root_complex_node;
>  
> +/*
> + *  STAO Status Override Table
> + *    http://wiki.xenproject.org/mediawiki/images/0/02/Status-override-table.pdf
> + */
> +typedef struct {
> +	fwts_acpi_table_header  header;
> +	uint8_t		uart;
> +	uint8_t		namelist[0];
> +} __attribute__ ((packed)) fwts_acpi_table_stao;
> +
>  #endif
> 

Acked-by: Alex Hung <alex.hung@canonical.com>
diff mbox

Patch

diff --git a/src/Makefile.am b/src/Makefile.am
index 6821216..e9b7180 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -77,10 +77,11 @@  fwts_SOURCES = main.c 				\
 	acpi/slit/slit.c 			\
 	acpi/spcr/spcr.c 			\
 	acpi/spmi/spmi.c 			\
-	acpi/tcpa/tcpa.c 			\
-	acpi/tpm2/tpm2.c 			\
 	acpi/srat/srat.c 			\
+	acpi/stao/stao.c			\
 	acpi/syntaxcheck/syntaxcheck.c 		\
+	acpi/tcpa/tcpa.c 			\
+	acpi/tpm2/tpm2.c 			\
 	acpi/uefi/uefi.c			\
 	acpi/waet/waet.c			\
 	acpi/wakealarm/wakealarm.c 		\
diff --git a/src/acpi/stao/stao.c b/src/acpi/stao/stao.c
new file mode 100644
index 0000000..b0243d0
--- /dev/null
+++ b/src/acpi/stao/stao.c
@@ -0,0 +1,219 @@ 
+/*
+ * Copyright (C) 2015 Canonical
+ *
+ * Portions of this code original from the Linux-ready Firmware Developer Kit
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ */
+#include "fwts.h"
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <inttypes.h>
+#include <string.h>
+
+#include "fwts_acpi_object_eval.h"
+
+static fwts_acpi_table_info *table;
+
+static int stao_init(fwts_framework *fw)
+{
+
+	if (fwts_acpi_find_table(fw, "STAO", 0, &table) != FWTS_OK) {
+		fwts_log_error(fw, "Cannot read ACPI tables.");
+		return FWTS_ERROR;
+	}
+	if (table == NULL || (table && table->length == 0)) {
+		fwts_log_error(fw, "ACPI STAO table does not exist, skipping test");
+		return FWTS_SKIP;
+	}
+
+	return FWTS_OK;
+}
+
+/*
+ *  Extract a STAO ACPI String from the raw buffer
+ */
+static bool stao_acpi_string(
+	fwts_framework *fw,
+	char *str,
+	char *end,
+	bool *passed,
+	size_t *len)
+{
+	char *ptr = str;
+
+	while (*ptr) {
+		if (ptr > end) {
+			*passed = false;
+			fwts_failed(fw, LOG_LEVEL_HIGH,
+				"STAOAcpiStringNotNullTerminated",
+				"STAO ACPI String has reached the end of the "
+				"ACPI table and did not have a 0x00 string "
+				"terminator");
+			*len = 0;
+			return false;
+		}
+		ptr++;
+	}
+	*len = ptr - str;
+	return true;
+}
+
+/*
+ *  STAO Status Override Table
+ *    http://wiki.xenproject.org/mediawiki/images/0/02/Status-override-table.pdf
+ */
+static int stao_test1(fwts_framework *fw)
+{
+	const fwts_acpi_table_stao *stao = (const fwts_acpi_table_stao *)table->data;
+	bool passed = true;
+	char *ptr, *end;
+	fwts_list_link  *item;
+	fwts_list *objects;
+	int i = -1, strings = 0;
+	char *ptr1, *ptr2;
+	char *expanded;
+
+	if (stao->header.length > (uint32_t)table->length) {
+		passed = false;
+		fwts_failed(fw, LOG_LEVEL_MEDIUM,
+			"STAOBadLength",
+			"STAO header reports that the table is %" PRIu32
+			" bytes long, however this is longer than the ACPI "
+			"table size of %zu bytes.",
+			stao->header.length,
+			table->length);
+		goto done;
+	}
+
+	/* Now we have got some sane data, dump the STAO */
+        fwts_log_info_verbatum(fw, "STAO Status Override Table:");
+        fwts_log_info_verbatum(fw, "  UART:                     0x%2.2" PRIx8, stao->uart);
+
+	ptr = (char *)stao->namelist;
+	end = (char *)table->data + stao->header.length;
+
+	while (ptr < end) {
+		size_t len;
+
+		if (!stao_acpi_string(fw, ptr, end, &passed, &len))
+			break;
+
+		fwts_log_info_verbatum(fw, "  ACPI String:              '%s'", ptr);
+		strings++;
+		/*  String length + null byte */
+		ptr += len + 1;
+	}
+	if (!strings)
+		goto done;
+
+        if (fwts_acpi_init(fw) != FWTS_OK) {
+		fwts_log_error(fw, "Cannot initialise ACPI, skipping ACPI string check");
+		goto done;
+	}
+	if ((objects = fwts_acpi_object_get_names()) == NULL) {
+		fwts_log_info(fw, "Cannot find any ACPI objects");
+		fwts_acpi_deinit(fw);
+		goto deinit;
+	}
+	ptr = (char *)stao->namelist;
+	end = (char *)table->data + table->length;
+
+	while (ptr < end) {
+		bool not_found = true;
+		size_t len;
+
+		if (!stao_acpi_string(fw, ptr, end, &passed, &len))
+			break;
+
+		/* Find number of '.' in object path */
+		for (i = 0, ptr1 = ptr; *ptr1; ptr1++) {
+			if (*ptr1 == '.')
+				i++;
+		}
+
+		/*
+		 *  Allocate buffer big enough to take expanded path
+		 *  and pad out any fields that are not 4 chars in size
+		 *  between each . separator
+		 *
+		 *  Converts \_SB.A.BB.CCC.DDDD.EE to
+		 *	     \_SB_.A___.BB__.CCC_.DDDD.EE__
+		 */
+		expanded = malloc(1 + (5 * (i + 1)));
+		if (!expanded) {
+			fwts_log_error(fw, "Cannot allocate temporary ACPI string buffer");
+			goto deinit;
+		}
+
+		for (i = -1, ptr1 = ptr, ptr2 = expanded; ; ptr1++) {
+			if (*ptr1 == '.' || *ptr1 == '\0') {
+				while (i < 4) {
+					*ptr2++ = '_';
+					i++;
+				}
+				i = 0;
+			} else {
+				i++;
+			}
+			*ptr2++ = *ptr1;
+			if (!*ptr1)
+				break;
+		}
+
+		/* Search for object */
+		fwts_list_foreach(item, objects) {
+			char *name = fwts_list_data(char *, item);
+			if (!strcmp(expanded, name)) {
+				not_found = false;
+				break;
+			}
+		}
+
+		if (not_found) {
+			passed = false;
+			fwts_failed(fw, LOG_LEVEL_HIGH,
+				"STAOAcpiStringNotFound",
+				"STAO ACPI String '%s' not found in ACPI object name space.",
+				expanded);
+		}
+		free(expanded);
+		ptr += len + 1;
+	}
+
+deinit:
+	fwts_acpi_deinit(fw);
+done:
+	if (passed)
+		fwts_passed(fw, "No issues found in STAO table.");
+
+	return FWTS_OK;
+}
+
+static fwts_framework_minor_test stao_tests[] = {
+	{ stao_test1, "STAO Status Override Table test." },
+	{ NULL, NULL }
+};
+
+static fwts_framework_ops stao_ops = {
+	.description = "STAO Status Override Table test.",
+	.init        = stao_init,
+	.minor_tests = stao_tests
+};
+
+FWTS_REGISTER("stao", &stao_ops, FWTS_TEST_ANYTIME, FWTS_FLAG_BATCH | FWTS_FLAG_TEST_ACPI)
diff --git a/src/lib/include/fwts_acpi.h b/src/lib/include/fwts_acpi.h
index b4a4ba2..4ee8cb2 100644
--- a/src/lib/include/fwts_acpi.h
+++ b/src/lib/include/fwts_acpi.h
@@ -1270,4 +1270,14 @@  typedef struct {
 	*/
 } __attribute__ ((packed)) fwts_acpi_table_iort_pci_root_complex_node;
 
+/*
+ *  STAO Status Override Table
+ *    http://wiki.xenproject.org/mediawiki/images/0/02/Status-override-table.pdf
+ */
+typedef struct {
+	fwts_acpi_table_header  header;
+	uint8_t		uart;
+	uint8_t		namelist[0];
+} __attribute__ ((packed)) fwts_acpi_table_stao;
+
 #endif