Linux_SDK_V0.9.5Linux_SDK_V0.9.5

1 files changed, 643 insertions, 0 deletions

diff --git a/lib/efi_loader/efi_variable.c b/lib/efi_loader/efi_variable.c
new file mode 100644
index 00000000..c316bdfe
--- /dev/null
+++ b/lib/efi_loader/efi_variable.c
@@ -0,0 +1,643 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  EFI utils
+ *
+ *  Copyright (c) 2017 Rob Clark
+ */
+
+#include <common.h>
+#include <efi_loader.h>
+#include <env_internal.h>
+#include <hexdump.h>
+#include <malloc.h>
+#include <search.h>
+#include <u-boot/crc.h>
+
+#define READ_ONLY BIT(31)
+
+/*
+ * Mapping between EFI variables and u-boot variables:
+ *
+ *   efi_$guid_$varname = {attributes}(type)value
+ *
+ * For example:
+ *
+ *   efi_8be4df61-93ca-11d2-aa0d-00e098032b8c_OsIndicationsSupported=
+ *      "{ro,boot,run}(blob)0000000000000000"
+ *   efi_8be4df61-93ca-11d2-aa0d-00e098032b8c_BootOrder=
+ *      "(blob)00010000"
+ *
+ * The attributes are a comma separated list of these possible
+ * attributes:
+ *
+ *   + ro   - read-only
+ *   + boot - boot-services access
+ *   + run  - runtime access
+ *
+ * NOTE: with current implementation, no variables are available after
+ * ExitBootServices, and all are persisted (if possible).
+ *
+ * If not specified, the attributes default to "{boot}".
+ *
+ * The required type is one of:
+ *
+ *   + utf8 - raw utf8 string
+ *   + blob - arbitrary length hex string
+ *
+ * Maybe a utf16 type would be useful to for a string value to be auto
+ * converted to utf16?
+ */
+
+#define PREFIX_LEN (strlen("efi_xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx_"))
+
+/**
+ * efi_to_native() - convert the UEFI variable name and vendor GUID to U-Boot
+ *		     variable name
+ *
+ * The U-Boot variable name is a concatenation of prefix 'efi', the hexstring
+ * encoded vendor GUID, and the UTF-8 encoded UEFI variable name separated by
+ * underscores, e.g. 'efi_8be4df61-93ca-11d2-aa0d-00e098032b8c_BootOrder'.
+ *
+ * @native:		pointer to pointer to U-Boot variable name
+ * @variable_name:	UEFI variable name
+ * @vendor:		vendor GUID
+ * Return:		status code
+ */
+static efi_status_t efi_to_native(char **native, const u16 *variable_name,
+				  const efi_guid_t *vendor)
+{
+	size_t len;
+	char *pos;
+
+	len = PREFIX_LEN + utf16_utf8_strlen(variable_name) + 1;
+	*native = malloc(len);
+	if (!*native)
+		return EFI_OUT_OF_RESOURCES;
+
+	pos = *native;
+	pos += sprintf(pos, "efi_%pUl_", vendor);
+	utf16_utf8_strcpy(&pos, variable_name);
+
+	return EFI_SUCCESS;
+}
+
+/**
+ * prefix() - skip over prefix
+ *
+ * Skip over a prefix string.
+ *
+ * @str:	string with prefix
+ * @prefix:	prefix string
+ * Return:	string without prefix, or NULL if prefix not found
+ */
+static const char *prefix(const char *str, const char *prefix)
+{
+	size_t n = strlen(prefix);
+	if (!strncmp(prefix, str, n))
+		return str + n;
+	return NULL;
+}
+
+/**
+ * parse_attr() - decode attributes part of variable value
+ *
+ * Convert the string encoded attributes of a UEFI variable to a bit mask.
+ * TODO: Several attributes are not supported.
+ *
+ * @str:	value of U-Boot variable
+ * @attrp:	pointer to UEFI attributes
+ * Return:	pointer to remainder of U-Boot variable value
+ */
+static const char *parse_attr(const char *str, u32 *attrp)
+{
+	u32 attr = 0;
+	char sep = '{';
+
+	if (*str != '{') {
+		*attrp = EFI_VARIABLE_BOOTSERVICE_ACCESS;
+		return str;
+	}
+
+	while (*str == sep) {
+		const char *s;
+
+		str++;
+
+		if ((s = prefix(str, "ro"))) {
+			attr |= READ_ONLY;
+		} else if ((s = prefix(str, "nv"))) {
+			attr |= EFI_VARIABLE_NON_VOLATILE;
+		} else if ((s = prefix(str, "boot"))) {
+			attr |= EFI_VARIABLE_BOOTSERVICE_ACCESS;
+		} else if ((s = prefix(str, "run"))) {
+			attr |= EFI_VARIABLE_RUNTIME_ACCESS;
+		} else {
+			printf("invalid attribute: %s\n", str);
+			break;
+		}
+
+		str = s;
+		sep = ',';
+	}
+
+	str++;
+
+	*attrp = attr;
+
+	return str;
+}
+
+/**
+ * efi_get_variable() - retrieve value of a UEFI variable
+ *
+ * This function implements the GetVariable runtime service.
+ *
+ * See the Unified Extensible Firmware Interface (UEFI) specification for
+ * details.
+ *
+ * @variable_name:	name of the variable
+ * @vendor:		vendor GUID
+ * @attributes:		attributes of the variable
+ * @data_size:		size of the buffer to which the variable value is copied
+ * @data:		buffer to which the variable value is copied
+ * Return:		status code
+ */
+efi_status_t EFIAPI efi_get_variable(u16 *variable_name,
+				     const efi_guid_t *vendor, u32 *attributes,
+				     efi_uintn_t *data_size, void *data)
+{
+	char *native_name;
+	efi_status_t ret;
+	unsigned long in_size;
+	const char *val, *s;
+	u32 attr;
+
+	EFI_ENTRY("\"%ls\" %pUl %p %p %p", variable_name, vendor, attributes,
+		  data_size, data);
+
+	if (!variable_name || !vendor || !data_size)
+		return EFI_EXIT(EFI_INVALID_PARAMETER);
+
+	ret = efi_to_native(&native_name, variable_name, vendor);
+	if (ret)
+		return EFI_EXIT(ret);
+
+	EFI_PRINT("get '%s'\n", native_name);
+
+	val = env_get(native_name);
+	free(native_name);
+	if (!val)
+		return EFI_EXIT(EFI_NOT_FOUND);
+
+	val = parse_attr(val, &attr);
+
+	in_size = *data_size;
+
+	if ((s = prefix(val, "(blob)"))) {
+		size_t len = strlen(s);
+
+		/* number of hexadecimal digits must be even */
+		if (len & 1)
+			return EFI_EXIT(EFI_DEVICE_ERROR);
+
+		/* two characters per byte: */
+		len /= 2;
+		*data_size = len;
+
+		if (in_size < len) {
+			ret = EFI_BUFFER_TOO_SMALL;
+			goto out;
+		}
+
+		if (!data)
+			return EFI_EXIT(EFI_INVALID_PARAMETER);
+
+		if (hex2bin(data, s, len))
+			return EFI_EXIT(EFI_DEVICE_ERROR);
+
+		EFI_PRINT("got value: \"%s\"\n", s);
+	} else if ((s = prefix(val, "(utf8)"))) {
+		unsigned len = strlen(s) + 1;
+
+		*data_size = len;
+
+		if (in_size < len) {
+			ret = EFI_BUFFER_TOO_SMALL;
+			goto out;
+		}
+
+		if (!data)
+			return EFI_EXIT(EFI_INVALID_PARAMETER);
+
+		memcpy(data, s, len);
+		((char *)data)[len] = '\0';
+
+		EFI_PRINT("got value: \"%s\"\n", (char *)data);
+	} else {
+		EFI_PRINT("invalid value: '%s'\n", val);
+		return EFI_EXIT(EFI_DEVICE_ERROR);
+	}
+
+out:
+	if (attributes)
+		*attributes = attr & EFI_VARIABLE_MASK;
+
+	return EFI_EXIT(ret);
+}
+
+static char *efi_variables_list;
+static char *efi_cur_variable;
+
+/**
+ * parse_uboot_variable() - parse a u-boot variable and get uefi-related
+ *			    information
+ * @variable:		whole data of u-boot variable (ie. name=value)
+ * @variable_name_size: size of variable_name buffer in byte
+ * @variable_name:	name of uefi variable in u16, null-terminated
+ * @vendor:		vendor's guid
+ * @attributes:		attributes
+ *
+ * A uefi variable is encoded into a u-boot variable as described above.
+ * This function parses such a u-boot variable and retrieve uefi-related
+ * information into respective parameters. In return, variable_name_size
+ * is the size of variable name including NULL.
+ *
+ * Return:		EFI_SUCCESS if parsing is OK, EFI_NOT_FOUND when
+ *			the entire variable list has been returned,
+ *			otherwise non-zero status code
+ */
+static efi_status_t parse_uboot_variable(char *variable,
+					 efi_uintn_t *variable_name_size,
+					 u16 *variable_name,
+					 const efi_guid_t *vendor,
+					 u32 *attributes)
+{
+	char *guid, *name, *end, c;
+	unsigned long name_len;
+	u16 *p;
+
+	guid = strchr(variable, '_');
+	if (!guid)
+		return EFI_INVALID_PARAMETER;
+	guid++;
+	name = strchr(guid, '_');
+	if (!name)
+		return EFI_INVALID_PARAMETER;
+	name++;
+	end = strchr(name, '=');
+	if (!end)
+		return EFI_INVALID_PARAMETER;
+
+	name_len = end - name;
+	if (*variable_name_size < (name_len + 1)) {
+		*variable_name_size = name_len + 1;
+		return EFI_BUFFER_TOO_SMALL;
+	}
+	end++; /* point to value */
+
+	/* variable name */
+	p = variable_name;
+	utf8_utf16_strncpy(&p, name, name_len);
+	variable_name[name_len] = 0;
+	*variable_name_size = name_len + 1;
+
+	/* guid */
+	c = *(name - 1);
+	*(name - 1) = '\0'; /* guid need be null-terminated here */
+	uuid_str_to_bin(guid, (unsigned char *)vendor, UUID_STR_FORMAT_GUID);
+	*(name - 1) = c;
+
+	/* attributes */
+	parse_attr(end, attributes);
+
+	return EFI_SUCCESS;
+}
+
+/**
+ * efi_get_next_variable_name() - enumerate the current variable names
+ *
+ * @variable_name_size:	size of variable_name buffer in byte
+ * @variable_name:	name of uefi variable's name in u16
+ * @vendor:		vendor's guid
+ *
+ * This function implements the GetNextVariableName service.
+ *
+ * See the Unified Extensible Firmware Interface (UEFI) specification for
+ * details.
+ *
+ * Return: status code
+ */
+efi_status_t EFIAPI efi_get_next_variable_name(efi_uintn_t *variable_name_size,
+					       u16 *variable_name,
+					       const efi_guid_t *vendor)
+{
+	char *native_name, *variable;
+	ssize_t name_len, list_len;
+	char regex[256];
+	char * const regexlist[] = {regex};
+	u32 attributes;
+	int i;
+	efi_status_t ret;
+
+	EFI_ENTRY("%p \"%ls\" %pUl", variable_name_size, variable_name, vendor);
+
+	if (!variable_name_size || !variable_name || !vendor)
+		return EFI_EXIT(EFI_INVALID_PARAMETER);
+
+	if (variable_name[0]) {
+		/* check null-terminated string */
+		for (i = 0; i < *variable_name_size; i++)
+			if (!variable_name[i])
+				break;
+		if (i >= *variable_name_size)
+			return EFI_EXIT(EFI_INVALID_PARAMETER);
+
+		/* search for the last-returned variable */
+		ret = efi_to_native(&native_name, variable_name, vendor);
+		if (ret)
+			return EFI_EXIT(ret);
+
+		name_len = strlen(native_name);
+		for (variable = efi_variables_list; variable && *variable;) {
+			if (!strncmp(variable, native_name, name_len) &&
+			    variable[name_len] == '=')
+				break;
+
+			variable = strchr(variable, '\n');
+			if (variable)
+				variable++;
+		}
+
+		free(native_name);
+		if (!(variable && *variable))
+			return EFI_EXIT(EFI_INVALID_PARAMETER);
+
+		/* next variable */
+		variable = strchr(variable, '\n');
+		if (variable)
+			variable++;
+		if (!(variable && *variable))
+			return EFI_EXIT(EFI_NOT_FOUND);
+	} else {
+		/*
+		 *new search: free a list used in the previous search
+		 */
+		free(efi_variables_list);
+		efi_variables_list = NULL;
+		efi_cur_variable = NULL;
+
+		snprintf(regex, 256, "efi_.*-.*-.*-.*-.*_.*");
+		list_len = hexport_r(&env_htab, '\n',
+				     H_MATCH_REGEX | H_MATCH_KEY,
+				     &efi_variables_list, 0, 1, regexlist);
+		/* 1 indicates that no match was found */
+		if (list_len <= 1)
+			return EFI_EXIT(EFI_NOT_FOUND);
+
+		variable = efi_variables_list;
+	}
+
+	ret = parse_uboot_variable(variable, variable_name_size, variable_name,
+				   vendor, &attributes);
+
+	return EFI_EXIT(ret);
+}
+
+/**
+ * efi_set_variable() - set value of a UEFI variable
+ *
+ * This function implements the SetVariable runtime service.
+ *
+ * See the Unified Extensible Firmware Interface (UEFI) specification for
+ * details.
+ *
+ * @variable_name:	name of the variable
+ * @vendor:		vendor GUID
+ * @attributes:		attributes of the variable
+ * @data_size:		size of the buffer with the variable value
+ * @data:		buffer with the variable value
+ * Return:		status code
+ */
+efi_status_t EFIAPI efi_set_variable(u16 *variable_name,
+				     const efi_guid_t *vendor, u32 attributes,
+				     efi_uintn_t data_size, const void *data)
+{
+	char *native_name = NULL, *val = NULL, *s;
+	const char *old_val;
+	size_t old_size;
+	efi_status_t ret = EFI_SUCCESS;
+	u32 attr;
+
+	EFI_ENTRY("\"%ls\" %pUl %x %zu %p", variable_name, vendor, attributes,
+		  data_size, data);
+
+	if (!variable_name || !*variable_name || !vendor ||
+	    ((attributes & EFI_VARIABLE_RUNTIME_ACCESS) &&
+	     !(attributes & EFI_VARIABLE_BOOTSERVICE_ACCESS))) {
+		ret = EFI_INVALID_PARAMETER;
+		goto out;
+	}
+
+	ret = efi_to_native(&native_name, variable_name, vendor);
+	if (ret)
+		goto out;
+
+	old_val = env_get(native_name);
+	if (old_val) {
+		old_val = parse_attr(old_val, &attr);
+
+		/* check read-only first */
+		if (attr & READ_ONLY) {
+			ret = EFI_WRITE_PROTECTED;
+			goto out;
+		}
+
+		if ((data_size == 0 &&
+		     !(attributes & EFI_VARIABLE_APPEND_WRITE)) ||
+		    !attributes) {
+			/* delete the variable: */
+			env_set(native_name, NULL);
+			ret = EFI_SUCCESS;
+			goto out;
+		}
+
+		/* attributes won't be changed */
+		if (attr != (attributes & ~EFI_VARIABLE_APPEND_WRITE)) {
+			ret = EFI_INVALID_PARAMETER;
+			goto out;
+		}
+
+		if (attributes & EFI_VARIABLE_APPEND_WRITE) {
+			if (!prefix(old_val, "(blob)")) {
+				ret = EFI_DEVICE_ERROR;
+				goto out;
+			}
+			old_size = strlen(old_val);
+		} else {
+			old_size = 0;
+		}
+	} else {
+		if (data_size == 0 || !attributes ||
+		    (attributes & EFI_VARIABLE_APPEND_WRITE)) {
+			/*
+			 * Trying to delete or to update a non-existent
+			 * variable.
+			 */
+			ret = EFI_NOT_FOUND;
+			goto out;
+		}
+
+		old_size = 0;
+	}
+
+	val = malloc(old_size + 2 * data_size
+		     + strlen("{ro,run,boot,nv}(blob)") + 1);
+	if (!val) {
+		ret = EFI_OUT_OF_RESOURCES;
+		goto out;
+	}
+
+	s = val;
+
+	/* store attributes */
+	attributes &= (EFI_VARIABLE_NON_VOLATILE |
+		       EFI_VARIABLE_BOOTSERVICE_ACCESS |
+		       EFI_VARIABLE_RUNTIME_ACCESS);
+	s += sprintf(s, "{");
+	while (attributes) {
+		u32 attr = 1 << (ffs(attributes) - 1);
+
+		if (attr == EFI_VARIABLE_NON_VOLATILE)
+			s += sprintf(s, "nv");
+		else if (attr == EFI_VARIABLE_BOOTSERVICE_ACCESS)
+			s += sprintf(s, "boot");
+		else if (attr == EFI_VARIABLE_RUNTIME_ACCESS)
+			s += sprintf(s, "run");
+
+		attributes &= ~attr;
+		if (attributes)
+			s += sprintf(s, ",");
+	}
+	s += sprintf(s, "}");
+
+	if (old_size)
+		/* APPEND_WRITE */
+		s += sprintf(s, old_val);
+	else
+		s += sprintf(s, "(blob)");
+
+	/* store payload: */
+	s = bin2hex(s, data, data_size);
+	*s = '\0';
+
+	EFI_PRINT("setting: %s=%s\n", native_name, val);
+
+	if (env_set(native_name, val))
+		ret = EFI_DEVICE_ERROR;
+
+out:
+	free(native_name);
+	free(val);
+
+	return EFI_EXIT(ret);
+}
+
+/**
+ * efi_query_variable_info() - get information about EFI variables
+ *
+ * This function implements the QueryVariableInfo() runtime service.
+ *
+ * See the Unified Extensible Firmware Interface (UEFI) specification for
+ * details.
+ *
+ * @attributes:				bitmask to select variables to be
+ *					queried
+ * @maximum_variable_storage_size:	maximum size of storage area for the
+ *					selected variable types
+ * @remaining_variable_storage_size:	remaining size of storage are for the
+ *					selected variable types
+ * @maximum_variable_size:		maximum size of a variable of the
+ *					selected type
+ * Returns:				status code
+ */
+efi_status_t __efi_runtime EFIAPI efi_query_variable_info(
+			u32 attributes,
+			u64 *maximum_variable_storage_size,
+			u64 *remaining_variable_storage_size,
+			u64 *maximum_variable_size)
+{
+	return EFI_UNSUPPORTED;
+}
+
+/**
+ * efi_get_variable_runtime() - runtime implementation of GetVariable()
+ *
+ * @variable_name:	name of the variable
+ * @vendor:		vendor GUID
+ * @attributes:		attributes of the variable
+ * @data_size:		size of the buffer to which the variable value is copied
+ * @data:		buffer to which the variable value is copied
+ * Return:		status code
+ */
+static efi_status_t __efi_runtime EFIAPI
+efi_get_variable_runtime(u16 *variable_name, const efi_guid_t *vendor,
+			 u32 *attributes, efi_uintn_t *data_size, void *data)
+{
+	return EFI_UNSUPPORTED;
+}
+
+/**
+ * efi_get_next_variable_name_runtime() - runtime implementation of
+ *					  GetNextVariable()
+ *
+ * @variable_name_size:	size of variable_name buffer in byte
+ * @variable_name:	name of uefi variable's name in u16
+ * @vendor:		vendor's guid
+ * Return: status code
+ */
+static efi_status_t __efi_runtime EFIAPI
+efi_get_next_variable_name_runtime(efi_uintn_t *variable_name_size,
+				   u16 *variable_name, const efi_guid_t *vendor)
+{
+	return EFI_UNSUPPORTED;
+}
+
+/**
+ * efi_set_variable_runtime() - runtime implementation of SetVariable()
+ *
+ * @variable_name:	name of the variable
+ * @vendor:		vendor GUID
+ * @attributes:		attributes of the variable
+ * @data_size:		size of the buffer with the variable value
+ * @data:		buffer with the variable value
+ * Return:		status code
+ */
+static efi_status_t __efi_runtime EFIAPI
+efi_set_variable_runtime(u16 *variable_name, const efi_guid_t *vendor,
+			 u32 attributes, efi_uintn_t data_size,
+			 const void *data)
+{
+	return EFI_UNSUPPORTED;
+}
+
+/**
+ * efi_variables_boot_exit_notify() - notify ExitBootServices() is called
+ */
+void efi_variables_boot_exit_notify(void)
+{
+	efi_runtime_services.get_variable = efi_get_variable_runtime;
+	efi_runtime_services.get_next_variable_name =
+				efi_get_next_variable_name_runtime;
+	efi_runtime_services.set_variable = efi_set_variable_runtime;
+	efi_update_table_header_crc32(&efi_runtime_services.hdr);
+}
+
+/**
+ * efi_init_variables() - initialize variable services
+ *
+ * Return:	status code
+ */
+efi_status_t efi_init_variables(void)
+{
+	return EFI_SUCCESS;
+}