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-rw-r--r--src/drivers/efi/Kconfig6
-rw-r--r--src/drivers/efi/Makefile.inc5
-rw-r--r--src/drivers/efi/efivars.c654
-rw-r--r--src/drivers/efi/efivars.h47
4 files changed, 712 insertions, 0 deletions
diff --git a/src/drivers/efi/Kconfig b/src/drivers/efi/Kconfig
new file mode 100644
index 0000000000..192a9176a0
--- /dev/null
+++ b/src/drivers/efi/Kconfig
@@ -0,0 +1,6 @@
+config DRIVERS_EFI_VARIABLE_STORE
+ bool "Include EFI variable store driver"
+ depends on UDK_BASE
+ help
+ Adds a driver that is able to read and write an EFI formatted
+ VariableStore as used by tianocore.
diff --git a/src/drivers/efi/Makefile.inc b/src/drivers/efi/Makefile.inc
new file mode 100644
index 0000000000..e2251b2c2b
--- /dev/null
+++ b/src/drivers/efi/Makefile.inc
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+all-$(CONFIG_DRIVERS_EFI_VARIABLE_STORE) += efivars.c
+
+all-$(CONFIG_USE_UEFI_VARIABLE_STORE) += option.c
diff --git a/src/drivers/efi/efivars.c b/src/drivers/efi/efivars.c
new file mode 100644
index 0000000000..9a3233f11c
--- /dev/null
+++ b/src/drivers/efi/efivars.c
@@ -0,0 +1,654 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <console/console.h>
+
+#include <vendorcode/intel/edk2/UDK2017/MdePkg/Include/Uefi/UefiBaseType.h>
+#include <vendorcode/intel/edk2/UDK2017/MdePkg/Include/Uefi/UefiMultiPhase.h>
+#include <vendorcode/intel/edk2/UDK2017/MdePkg/Include/Pi/PiFirmwareVolume.h>
+#include <vendorcode/intel/edk2/UDK2017/MdeModulePkg/Include/Guid/VariableFormat.h>
+#include <lib.h>
+
+#include "efivars.h"
+
+#define PREFIX "EFIVARS: "
+
+static const EFI_GUID EfiVariableGuid = {
+ 0xddcf3616, 0x3275, 0x4164, { 0x98, 0xb6, 0xfe, 0x85, 0x70, 0x7f, 0xfe, 0x7d } };
+static const EFI_GUID EfiAuthenticatedVariableGuid = {
+ 0xaaf32c78, 0x947b, 0x439a, { 0xa1, 0x80, 0x2e, 0x14, 0x4e, 0xc3, 0x77, 0x92 } };
+static const EFI_GUID EfiSystemNvDataFvGuid = {
+ 0xfff12b8d, 0x7696, 0x4c8b, { 0xa9, 0x85, 0x27, 0x47, 0x07, 0x5b, 0x4f, 0x50 } };
+
+static void print_guid(int log_level, const EFI_GUID *g)
+{
+ printk(log_level, "GUID: %08x-%04x-%04x-%02x%02x%02x%02x%02x%02x%02x%02x",
+ g->Data1, g->Data2, g->Data3, g->Data4[0], g->Data4[1], g->Data4[2],
+ g->Data4[3], g->Data4[4], g->Data4[5], g->Data4[6], g->Data4[7]);
+
+}
+
+static bool compare_guid(const EFI_GUID *a, const EFI_GUID *b)
+{
+ return memcmp(a, b, sizeof(*a)) == 0;
+}
+
+/* Reads the CHAR16 string from rdev at offset and prints it */
+static enum cb_err rdev_print_wchar(int log_level, struct region_device *rdev, size_t offset)
+{
+ CHAR16 c;
+ int i = 0;
+
+ /* Convert ASCII to UTF-16 */
+ do {
+ if (rdev_readat(rdev, &c, offset + i * sizeof(c), sizeof(c)) != sizeof(c))
+ return CB_EFI_ACCESS_ERROR;
+ if (c < 0x80)
+ printk(log_level, "%c", (char)c);
+ else
+ printk(log_level, "\\u%04x", c);
+
+ i++;
+ } while (c);
+ return CB_SUCCESS;
+}
+
+/* Convert an ASCII string to UTF-16 and write it to the rdev starting at offset. */
+static enum cb_err rdev_write_wchar(struct region_device *rdev, size_t offset, const char *msg)
+{
+ size_t i;
+ CHAR16 c;
+
+ /* Convert ASCII to UTF-16 */
+ for (i = 0; i < strlen(msg) + 1; i++) {
+ c = msg[i];
+
+ if (rdev_writeat(rdev, &c, offset + i * sizeof(c), sizeof(c)) != sizeof(c))
+ return CB_EFI_ACCESS_ERROR;
+ }
+ return CB_SUCCESS;
+}
+
+/* Read an UTF-16 string from rdev at offset and compare it to ASCII string */
+static int rdev_strcmp_wchar_ascii(struct region_device *rdev, size_t offset, const char *msg)
+{
+ size_t i;
+ CHAR16 c;
+ int r;
+
+ i = 0;
+ /* Compare UTF-16 and ASCII */
+ while (1) {
+ if (rdev_readat(rdev, &c, offset + i * sizeof(c), sizeof(c)) != sizeof(c))
+ return CB_EFI_ACCESS_ERROR;
+ if ((r = (c - msg[i])) != 0 || !c)
+ break;
+
+ i++;
+ }
+ return r;
+}
+
+/* Compare an rdev region and a data buffer */
+static int rdev_memcmp(struct region_device *rdev, size_t offset, uint8_t *data, size_t size)
+{
+ uint8_t buf[16];
+ size_t i;
+ int r;
+
+ i = 0;
+ while (size >= sizeof(buf)) {
+ if (rdev_readat(rdev, buf, offset + i, sizeof(buf)) != sizeof(buf))
+ return CB_EFI_ACCESS_ERROR;
+ r = memcmp(buf, data + i, sizeof(buf));
+ if (r != 0)
+ return r;
+ i += sizeof(buf);
+ size -= sizeof(buf);
+ }
+ while (size > 0) {
+ if (rdev_readat(rdev, buf, offset + i, 1) != 1)
+ return CB_EFI_ACCESS_ERROR;
+ r = buf[0] - data[i];
+ if (r != 0)
+ return r;
+ i++;
+ size--;
+ }
+ return 0;
+}
+
+
+static enum cb_err validate_fv_header(const struct region_device *rdev,
+ EFI_FIRMWARE_VOLUME_HEADER *fw_vol_hdr)
+{
+ uint16_t checksum, data;
+ size_t i;
+
+ if (rdev_readat(rdev, fw_vol_hdr, 0, sizeof(*fw_vol_hdr)) != sizeof(*fw_vol_hdr))
+ return CB_EFI_ACCESS_ERROR;
+
+ /*
+ * Verify the header revision, header signature, length
+ * Length of FvBlock cannot be 2**64-1
+ * HeaderLength cannot be an odd number
+ */
+ if ((fw_vol_hdr->Revision != EFI_FVH_REVISION)
+ || (fw_vol_hdr->Signature != EFI_FVH_SIGNATURE)
+ || (fw_vol_hdr->FvLength > region_device_sz(rdev))
+ || (fw_vol_hdr->HeaderLength > region_device_sz(rdev))
+ || (fw_vol_hdr->HeaderLength & 1)) {
+ printk(BIOS_WARNING, PREFIX "No Firmware Volume header present\n");
+ return CB_EFI_FVH_INVALID;
+ }
+
+ /* Check the Firmware Volume Guid */
+ if (!compare_guid(&fw_vol_hdr->FileSystemGuid, &EfiSystemNvDataFvGuid)) {
+ printk(BIOS_WARNING, PREFIX "Firmware Volume Guid non-compatible\n");
+ return CB_EFI_FVH_INVALID;
+ }
+
+ /* Verify the header checksum */
+ checksum = 0;
+ for (i = 0; i < fw_vol_hdr->HeaderLength; i += 2) {
+ if (rdev_readat(rdev, &data, i, sizeof(data)) != sizeof(data))
+ return CB_EFI_ACCESS_ERROR;
+ checksum = (uint16_t)(checksum + data); /* intentionally overflows */
+ }
+ if (checksum != 0) {
+ printk(BIOS_WARNING, PREFIX "FV checksum is invalid: 0x%X\n", checksum);
+ return CB_EFI_CHECKSUM_INVALID;
+ }
+
+ printk(BIOS_SPEW, PREFIX "UEFI FV with size %lld found\n", fw_vol_hdr->FvLength);
+
+ return CB_SUCCESS;
+
+}
+
+static enum cb_err
+validate_variable_store_header(const EFI_FIRMWARE_VOLUME_HEADER *fv_hdr,
+ struct region_device *rdev,
+ bool *auth_format)
+{
+ VARIABLE_STORE_HEADER hdr;
+ size_t length;
+
+ if (rdev_readat(rdev, &hdr, fv_hdr->HeaderLength, sizeof(hdr)) != sizeof(hdr))
+ return CB_EFI_ACCESS_ERROR;
+
+ /* Check the Variable Store Guid */
+ if (!compare_guid(&hdr.Signature, &EfiVariableGuid) &&
+ !compare_guid(&hdr.Signature, &EfiAuthenticatedVariableGuid)) {
+ printk(BIOS_WARNING, PREFIX "Variable Store Guid non-compatible\n");
+ return CB_EFI_VS_CORRUPTED_INVALID;
+ }
+
+ *auth_format = compare_guid(&hdr.Signature, &EfiAuthenticatedVariableGuid);
+
+ length = region_device_sz(rdev) - fv_hdr->HeaderLength;
+ if (hdr.Size > length) {
+ printk(BIOS_WARNING, PREFIX "Variable Store Length does not match\n");
+ return CB_EFI_VS_CORRUPTED_INVALID;
+ }
+
+ if (hdr.Format != VARIABLE_STORE_FORMATTED)
+ return CB_EFI_VS_NOT_FORMATTED_INVALID;
+
+ if (hdr.State != VARIABLE_STORE_HEALTHY)
+ return CB_EFI_VS_CORRUPTED_INVALID;
+
+ if (rdev_chain(rdev, rdev, fv_hdr->HeaderLength + sizeof(hdr), hdr.Size)) {
+ printk(BIOS_WARNING, PREFIX "rdev_chain failed\n");
+ return CB_EFI_ACCESS_ERROR;
+ }
+
+ printk(BIOS_SPEW, PREFIX "UEFI variable store with size %zu found\n",
+ region_device_sz(rdev));
+
+ return CB_SUCCESS;
+}
+
+struct efi_find_args {
+ const EFI_GUID *guid;
+ const char *name;
+ uint32_t *size;
+ void *data;
+};
+
+static bool match(struct region_device *rdev, VARIABLE_HEADER *hdr, size_t hdr_size,
+ const char *name, const EFI_GUID *guid)
+{
+ /* Only search for valid or in transition to be deleted variables */
+ if ((hdr->State != VAR_ADDED) &&
+ (hdr->State != (VAR_IN_DELETED_TRANSITION & VAR_ADDED)))
+ return false;
+
+ if ((!compare_guid(&hdr->VendorGuid, guid)) ||
+ !hdr->NameSize ||
+ !hdr->DataSize)
+ return false;
+
+ if (rdev_strcmp_wchar_ascii(rdev, hdr_size, name) != 0)
+ return false;
+
+ return true;
+}
+
+static
+enum cb_err find_and_copy(struct region_device *rdev, VARIABLE_HEADER *hdr, size_t hdr_size,
+ void *arg, bool *stop)
+{
+ struct efi_find_args *fa = (struct efi_find_args *)arg;
+
+ if (!match(rdev, hdr, hdr_size, fa->name, fa->guid))
+ return CB_SUCCESS;
+
+ *stop = true;
+ if (*(fa->size) < hdr->DataSize)
+ return CB_EFI_BUFFER_TOO_SMALL;
+
+ if (rdev_readat(rdev, fa->data, hdr_size + hdr->NameSize, hdr->DataSize) !=
+ hdr->DataSize)
+ return CB_EFI_ACCESS_ERROR;
+
+ *(fa->size) = hdr->DataSize;
+ return CB_SUCCESS;
+}
+
+struct efi_find_compare_args {
+ const EFI_GUID *guid;
+ const char *name;
+ uint32_t size;
+ void *data;
+ bool match;
+};
+
+static
+enum cb_err find_and_compare(struct region_device *rdev, VARIABLE_HEADER *hdr, size_t hdr_size,
+ void *arg, bool *stop)
+{
+ struct efi_find_compare_args *fa = (struct efi_find_compare_args *)arg;
+
+ if (!match(rdev, hdr, hdr_size, fa->name, fa->guid))
+ return CB_SUCCESS;
+
+ *stop = true;
+ if (fa->size != hdr->DataSize) {
+ fa->match = false;
+ return CB_SUCCESS;
+ }
+
+ fa->match = rdev_memcmp(rdev, hdr_size + hdr->NameSize, fa->data, hdr->DataSize) == 0;
+
+ return CB_SUCCESS;
+}
+
+static enum cb_err noop(struct region_device *rdev, VARIABLE_HEADER *hdr, size_t hdr_size,
+ void *arg, bool *stop)
+{
+ /* Does nothing. */
+ return CB_SUCCESS;
+}
+
+static enum cb_err print_var(struct region_device *rdev, VARIABLE_HEADER *hdr, size_t hdr_size,
+ void *arg, bool *stop)
+{
+ uint8_t buf[16];
+ size_t len, i;
+
+ printk(BIOS_DEBUG, "%08zx: Var ", region_device_offset(rdev));
+ print_guid(BIOS_DEBUG, &hdr->VendorGuid);
+
+ printk(BIOS_DEBUG, "-");
+
+ rdev_print_wchar(BIOS_DEBUG, rdev, hdr_size);
+
+ printk(BIOS_DEBUG, ", State %02x, Size %02x\n", hdr->State, hdr->DataSize);
+
+ if (hdr->DataSize && hdr->NameSize) {
+ len = sizeof(buf) < hdr->DataSize ? sizeof(buf) : hdr->DataSize;
+ if (rdev_readat(rdev, buf, hdr_size + hdr->NameSize, len) != len)
+ return CB_EFI_ACCESS_ERROR;
+ printk(BIOS_DEBUG, " Data: ");
+
+ for (i = 0; i < len; i++)
+ printk(BIOS_DEBUG, "0x%02x ", buf[i]);
+
+ if (hdr->DataSize > len)
+ printk(BIOS_DEBUG, "...");
+
+ printk(BIOS_DEBUG, "\n");
+ }
+
+ return CB_SUCCESS;
+}
+
+static enum cb_err walk_variables(struct region_device *rdev,
+ bool auth_format,
+ enum cb_err (*walker)(struct region_device *rdev,
+ VARIABLE_HEADER *hdr,
+ size_t hdr_size,
+ void *arg,
+ bool *stop),
+ void *walker_arg)
+{
+ AUTHENTICATED_VARIABLE_HEADER auth_hdr;
+ size_t header_size, var_size;
+ VARIABLE_HEADER hdr;
+ bool stop;
+ enum cb_err ret;
+
+ if (auth_format)
+ header_size = sizeof(AUTHENTICATED_VARIABLE_HEADER);
+ else
+ header_size = sizeof(VARIABLE_HEADER);
+
+ do {
+ if (auth_format) {
+ if (rdev_readat(rdev, &auth_hdr, 0, sizeof(auth_hdr))
+ != sizeof(auth_hdr))
+ return CB_EFI_ACCESS_ERROR;
+ hdr.Reserved = auth_hdr.Reserved;
+ hdr.StartId = auth_hdr.StartId;
+ hdr.State = auth_hdr.State;
+ hdr.Attributes = auth_hdr.Attributes;
+ hdr.NameSize = auth_hdr.NameSize;
+ hdr.DataSize = auth_hdr.DataSize;
+ memcpy(&hdr.VendorGuid, &auth_hdr.VendorGuid, sizeof(hdr.VendorGuid));
+ } else if (rdev_readat(rdev, &hdr, 0, sizeof(hdr)) != sizeof(hdr)) {
+ return CB_EFI_ACCESS_ERROR;
+ }
+ if (hdr.StartId != VARIABLE_DATA)
+ break;
+
+ if (hdr.State == UINT8_MAX ||
+ hdr.DataSize == UINT32_MAX ||
+ hdr.NameSize == UINT32_MAX ||
+ hdr.Attributes == UINT32_MAX) {
+ hdr.NameSize = 0;
+ hdr.DataSize = 0;
+ }
+
+ printk(BIOS_SPEW, "Found variable with state %02x and ", hdr.State);
+ print_guid(BIOS_SPEW, &hdr.VendorGuid);
+ printk(BIOS_SPEW, "\n");
+
+ stop = false;
+
+ ret = walker(rdev, &hdr, header_size, walker_arg, &stop);
+
+ if (ret != CB_SUCCESS || stop)
+ return ret;
+
+ var_size = ALIGN_UP(header_size + hdr.NameSize + hdr.DataSize,
+ HEADER_ALIGNMENT);
+ } while (!rdev_chain(rdev, rdev, var_size, region_device_sz(rdev) - var_size));
+
+ return CB_EFI_OPTION_NOT_FOUND;
+}
+
+static enum cb_err efi_fv_init(struct region_device *rdev, bool *auth_format)
+{
+ EFI_FIRMWARE_VOLUME_HEADER fv_hdr;
+ enum cb_err ret;
+
+ ret = validate_fv_header(rdev, &fv_hdr);
+ if (ret != CB_SUCCESS) {
+ printk(BIOS_WARNING, PREFIX "Failed to validate firmware header\n");
+
+ return ret;
+ }
+ ret = validate_variable_store_header(&fv_hdr, rdev, auth_format);
+ if (ret != CB_SUCCESS)
+ printk(BIOS_WARNING, PREFIX "Failed to validate variable store header\n");
+
+ return ret;
+}
+
+enum cb_err efi_fv_print_options(struct region_device *rdev)
+{
+ enum cb_err ret;
+ bool auth_format;
+
+ ret = efi_fv_init(rdev, &auth_format);
+ if (ret != CB_SUCCESS)
+ return ret;
+
+ return walk_variables(rdev, auth_format, print_var, NULL);
+}
+
+/*
+ * efi_fv_get_option
+ * - writes up to *size bytes into a buffer pointed to by *dest
+ * - rdev is the spi flash region to operate on
+ * - the FVH and variable store header must have been initialized by a third party
+ */
+enum cb_err efi_fv_get_option(struct region_device *rdev,
+ const EFI_GUID *guid,
+ const char *name,
+ void *dest,
+ uint32_t *size)
+{
+ struct efi_find_args args;
+ bool auth_format;
+ enum cb_err ret;
+
+ ret = efi_fv_init(rdev, &auth_format);
+ if (ret != CB_SUCCESS)
+ return ret;
+
+ args.guid = guid;
+ args.name = name;
+ args.size = size;
+ args.data = dest;
+
+ return walk_variables(rdev, auth_format, find_and_copy, &args);
+}
+
+static enum cb_err write_auth_hdr(struct region_device *rdev, const EFI_GUID *guid,
+ const char *name, void *data, size_t size)
+{
+ AUTHENTICATED_VARIABLE_HEADER auth_hdr;
+ size_t name_size, var_size;
+ enum cb_err ret;
+
+ name_size = (strlen(name) + 1) * sizeof(CHAR16);
+ var_size = name_size + size + sizeof(auth_hdr);
+
+ if (var_size > region_device_sz(rdev))
+ return CB_EFI_STORE_FULL;
+
+ /* Sanity check. flash must be blank */
+ if (rdev_readat(rdev, &auth_hdr, 0, sizeof(auth_hdr)) != sizeof(auth_hdr))
+ return CB_EFI_ACCESS_ERROR;
+
+ if (auth_hdr.StartId != UINT16_MAX ||
+ auth_hdr.State != UINT8_MAX ||
+ auth_hdr.DataSize != UINT32_MAX ||
+ auth_hdr.NameSize != UINT32_MAX ||
+ auth_hdr.Attributes != UINT32_MAX) {
+ return CB_EFI_ACCESS_ERROR;
+ }
+
+ memset(&auth_hdr, 0xff, sizeof(auth_hdr));
+
+ auth_hdr.StartId = VARIABLE_DATA;
+ auth_hdr.Attributes = EFI_VARIABLE_NON_VOLATILE|
+ EFI_VARIABLE_BOOTSERVICE_ACCESS|
+ EFI_VARIABLE_RUNTIME_ACCESS;
+ auth_hdr.NameSize = name_size;
+ auth_hdr.DataSize = size;
+ memcpy(&auth_hdr.VendorGuid, guid, sizeof(EFI_GUID));
+
+ /* Write header with no State */
+ if (rdev_writeat(rdev, &auth_hdr, 0, sizeof(auth_hdr)) != sizeof(auth_hdr))
+ return CB_EFI_ACCESS_ERROR;
+
+ /* Set header State to valid header */
+ auth_hdr.State = VAR_HEADER_VALID_ONLY;
+ if (rdev_writeat(rdev, &auth_hdr.State, offsetof(AUTHENTICATED_VARIABLE_HEADER, State),
+ sizeof(auth_hdr.State)) != sizeof(auth_hdr.State))
+ return CB_EFI_ACCESS_ERROR;
+
+ /* Write the name */
+ ret = rdev_write_wchar(rdev, sizeof(auth_hdr), name);
+ if (ret != CB_SUCCESS)
+ return ret;
+
+ /* Write the data */
+ if (rdev_writeat(rdev, data, sizeof(auth_hdr) + name_size, size) != size)
+ return CB_EFI_ACCESS_ERROR;
+
+ /* Set header State to valid data */
+ auth_hdr.State = VAR_ADDED;
+ if (rdev_writeat(rdev, &auth_hdr.State, offsetof(AUTHENTICATED_VARIABLE_HEADER, State),
+ sizeof(auth_hdr.State)) != sizeof(auth_hdr.State))
+ return CB_EFI_ACCESS_ERROR;
+
+ return CB_SUCCESS;
+}
+
+static enum cb_err write_hdr(struct region_device *rdev, const EFI_GUID *guid,
+ const char *name,
+ void *data,
+ size_t size)
+{
+ VARIABLE_HEADER hdr;
+ size_t name_size, var_size;
+ enum cb_err ret;
+
+ name_size = (strlen(name) + 1) * sizeof(CHAR16);
+ var_size = name_size + size + sizeof(hdr);
+ if (var_size > region_device_sz(rdev))
+ return CB_EFI_STORE_FULL;
+
+ /* Sanity check. flash must be blank */
+ if (rdev_readat(rdev, &hdr, 0, sizeof(hdr)) != sizeof(hdr))
+ return CB_EFI_ACCESS_ERROR;
+
+ if (hdr.StartId != UINT16_MAX ||
+ hdr.State != UINT8_MAX ||
+ hdr.DataSize != UINT32_MAX ||
+ hdr.NameSize != UINT32_MAX ||
+ hdr.Attributes != UINT32_MAX) {
+ return CB_EFI_ACCESS_ERROR;
+ }
+
+ memset(&hdr, 0xff, sizeof(hdr));
+
+ hdr.StartId = VARIABLE_DATA;
+ hdr.Attributes = EFI_VARIABLE_NON_VOLATILE|
+ EFI_VARIABLE_BOOTSERVICE_ACCESS|
+ EFI_VARIABLE_RUNTIME_ACCESS;
+ hdr.NameSize = name_size;
+ hdr.DataSize = size;
+ memcpy(&hdr.VendorGuid, guid, sizeof(EFI_GUID));
+
+ /* Write header with no State */
+ if (rdev_writeat(rdev, &hdr, 0, sizeof(hdr)) != sizeof(hdr))
+ return CB_EFI_ACCESS_ERROR;
+
+ /* Set header State to valid header */
+ hdr.State = VAR_HEADER_VALID_ONLY;
+ if (rdev_writeat(rdev, &hdr.State, offsetof(VARIABLE_HEADER, State),
+ sizeof(hdr.State)) != sizeof(hdr.State))
+ return CB_EFI_ACCESS_ERROR;
+
+ /* Write the name */
+ ret = rdev_write_wchar(rdev, sizeof(hdr), name);
+ if (ret != CB_SUCCESS)
+ return ret;
+
+ /* Write the data */
+ if (rdev_writeat(rdev, data, sizeof(hdr) + name_size, size) != size)
+ return CB_EFI_ACCESS_ERROR;
+
+ /* Set header State to valid data */
+ hdr.State = VAR_ADDED;
+ if (rdev_writeat(rdev, &hdr.State, offsetof(VARIABLE_HEADER, State),
+ sizeof(hdr.State)) != sizeof(hdr.State))
+ return CB_EFI_ACCESS_ERROR;
+
+ return CB_SUCCESS;
+}
+
+/*
+ * efi_fv_set_option
+ * - writes size bytes read from the buffer pointed to by *data
+ * - rdev is the spi flash region to operate on
+ * - the FVH and variable store header must have been initialized by a third party
+ */
+enum cb_err efi_fv_set_option(struct region_device *rdev,
+ const EFI_GUID *guid,
+ const char *name,
+ void *data,
+ uint32_t size)
+{
+ struct region_device rdev_old;
+ struct efi_find_compare_args args;
+ bool found_existing;
+ VARIABLE_HEADER hdr;
+ bool auth_format;
+ enum cb_err ret;
+
+ ret = efi_fv_init(rdev, &auth_format);
+ if (ret != CB_SUCCESS)
+ return ret;
+
+ /* Find existing variable */
+ args.guid = guid;
+ args.name = name;
+ args.size = size;
+ args.match = false;
+ args.data = data;
+
+ ret = walk_variables(rdev, auth_format, find_and_compare, &args);
+ found_existing = ret == CB_SUCCESS;
+
+ if (found_existing) {
+ printk(BIOS_ERR, "found existing variable %s, match =%d\n", name, args.match);
+
+ if (args.match)
+ return CB_SUCCESS;
+
+ rdev_old = *rdev;
+
+ /* Mark as to be deleted */
+ hdr.State = VAR_IN_DELETED_TRANSITION;
+ if (rdev_writeat(rdev, &hdr.State, offsetof(VARIABLE_HEADER, State),
+ sizeof(hdr.State)) != sizeof(hdr.State))
+ return CB_EFI_ACCESS_ERROR;
+ }
+
+ /* Walk to end of variable store */
+ ret = walk_variables(rdev, auth_format, noop, NULL);
+ if (ret != CB_EFI_OPTION_NOT_FOUND)
+ return ret;
+
+ /* Now append new variable:
+ * 1. Write the header without State field.
+ * 2. Write the State field and set it to HEADER_VALID.
+ * 3. Write data
+ * 4. Write the State field and set it to VAR_ADDED
+ */
+
+ if (auth_format)
+ ret = write_auth_hdr(rdev, guid, name, data, size);
+ else
+ ret = write_hdr(rdev, guid, name, data, size);
+ if (ret != CB_SUCCESS)
+ return ret;
+
+ if (found_existing) {
+ /* Mark old variable as deleted */
+ hdr.State = VAR_DELETED;
+ if (rdev_writeat(&rdev_old, &hdr.State, offsetof(VARIABLE_HEADER, State),
+ sizeof(hdr.State)) != sizeof(hdr.State))
+ return CB_EFI_ACCESS_ERROR;
+ }
+
+ return CB_SUCCESS;
+}
diff --git a/src/drivers/efi/efivars.h b/src/drivers/efi/efivars.h
new file mode 100644
index 0000000000..b3443b33b3
--- /dev/null
+++ b/src/drivers/efi/efivars.h
@@ -0,0 +1,47 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _EDK2_OPTION_H_
+#define _EDK2_OPTION_H_
+
+#include <types.h>
+#include <commonlib/region.h>
+
+#include <vendorcode/intel/edk2/UDK2017/MdePkg/Include/Uefi/UefiBaseType.h>
+
+/**
+ * efi_fv_get_option
+ * Use the provided EFI variable store inside the region device as variable store.
+ * @rdev: the readable region to operate on
+ * @guid: the vendor guid to look for
+ * @name: the variable name to look for. NULL terminated.
+ * @dest: memory buffer to place the result into
+ * @size: on input the size of buffer pointed to by dest.
+ * on output the number of bytes written.
+ */
+
+enum cb_err efi_fv_get_option(struct region_device *rdev,
+ const EFI_GUID *guid,
+ const char *name,
+ void *dest,
+ uint32_t *size);
+
+/**
+ * efi_fv_set_option
+ * Use the provided EFI variable store inside the region device as variable store.
+ * If the variable exists with the same size and contents, nothing will be written
+ * to the region device.
+ * @rdev: the read/writable region to operate on
+ * @guid: the vendor guid to write
+ * @name: the variable name to write. NULL terminated.
+ * @data: memory buffer where to read data from
+ * @size: the size of buffer pointed to by data
+ */
+enum cb_err efi_fv_set_option(struct region_device *rdev,
+ const EFI_GUID *guid,
+ const char *name,
+ void *data,
+ uint32_t size);
+
+enum cb_err efi_fv_print_options(struct region_device *rdev);
+
+#endif /* _EDK2_OPTION_H_ */
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-23 03:18:37 +0000