diff options
-rw-r--r-- | src/drivers/efi/Kconfig | 6 | ||||
-rw-r--r-- | src/drivers/efi/Makefile.inc | 5 | ||||
-rw-r--r-- | src/drivers/efi/efivars.c | 654 | ||||
-rw-r--r-- | src/drivers/efi/efivars.h | 47 | ||||
-rw-r--r-- | tests/Makefile.inc | 6 | ||||
-rw-r--r-- | tests/drivers/Makefile.inc | 14 | ||||
-rw-r--r-- | tests/drivers/efivars.c | 201 |
7 files changed, 930 insertions, 3 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_ */ diff --git a/tests/Makefile.inc b/tests/Makefile.inc index 3c25bd6f8e..584b4c0c9d 100644 --- a/tests/Makefile.inc +++ b/tests/Makefile.inc @@ -29,9 +29,9 @@ stages += ramstage rmodule postcar libagesa alltests := subdirs := tests/arch tests/acpi tests/commonlib tests/console tests/cpu -subdirs += tests/device tests/drivers tests/ec tests/lib tests/mainboard -subdirs += tests/northbridge tests/security tests/soc tests/southbridge -subdirs += tests/superio tests/vendorcode +subdirs += tests/device tests/drivers tests/ec tests/lib +subdirs += tests/mainboard tests/northbridge tests/security tests/soc +subdirs += tests/southbridge tests/superio tests/vendorcode define tests-handler alltests += $(1)$(2) diff --git a/tests/drivers/Makefile.inc b/tests/drivers/Makefile.inc new file mode 100644 index 0000000000..29b7ed7fdd --- /dev/null +++ b/tests/drivers/Makefile.inc @@ -0,0 +1,14 @@ +# SPDX-License-Identifier: GPL-2.0-only + +tests-y += efivars-test + +efivars-test-srcs += tests/drivers/efivars.c +efivars-test-srcs += src/drivers/efi/efivars.c +efivars-test-srcs += tests/stubs/console.c +efivars-test-srcs += src/commonlib/region.c + +efivars-test-cflags += -I src/vendorcode/intel/edk2/UDK2017/MdePkg/Include/ +efivars-test-cflags += -I src/vendorcode/intel/edk2/UDK2017/MdePkg/Include/Ia32/ +efivars-test-cflags += -I src/vendorcode/intel/edk2/UDK2017/MdePkg/Include/Pi/ +efivars-test-cflags += -I src/vendorcode/intel/edk2/UDK2017/MdeModulePkg/Include/ + diff --git a/tests/drivers/efivars.c b/tests/drivers/efivars.c new file mode 100644 index 0000000000..6899ce5bba --- /dev/null +++ b/tests/drivers/efivars.c @@ -0,0 +1,201 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#include <drivers/efi/efivars.h> +#include <limits.h> +#include <vendorcode/intel/edk2/UDK2017/MdePkg/Include/Pi/PiFirmwareVolume.h> +#include <vendorcode/intel/edk2/UDK2017/MdeModulePkg/Include/Guid/VariableFormat.h> +#include <string.h> +#include <tests/test.h> +#include <types.h> + +/* Dummy firmware volume header for a 0x30000 byte partition with a single entry + * in a formatted variable store. + */ +static const uint8_t FVH[] = { + /* EFI_FIRMWARE_VOLUME_HEADER */ + /* UINT8 ZeroVector[16] */ + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, + /* EFI_GUID FileSystemGuid */ + 0x8d, 0x2b, 0xf1, 0xff, 0x96, 0x76, 0x8b, 0x4c, 0xa9, 0x85, 0x27, 0x47, 0x07, 0x5b, + 0x4f, 0x50, + /* UINT64 FvLength */ + 0x00, 0x00, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, + /* UINT32 Signature */ + 0x5f, 0x46, 0x56, 0x48, + /* EFI_FVB_ATTRIBUTES_2 Attributes */ + 0x36, 0x0e, 0x00, 0x00, + /* UINT16 HeaderLength */ + 0x48, 0x00, + /* UINT16 Checksum */ + 0x00, 0xfa, + /* UINT16 ExtHeaderOffset */ + 0x00, 0x00, + /* UINT8 Reserved[1] */ + 0x00, + /* UINT8 Revision */ + 0x02, + /* EFI_FV_BLOCK_MAP_ENTRY BlockMap[2] */ + 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + + /* Variable Info Header */ + /* EFI_GUID Signature */ + 0x78, 0x2c, 0xf3, 0xaa, 0x7b, 0x94, 0x9a, 0x43, 0xa1, 0x80, 0x2e, 0x14, 0x4e, 0xc3, + 0x77, 0x92, + /* UINT32 Size */ + 0xb8, 0xff, 0x00, 0x00, + /* UINT8 Format */ + 0x5a, + /* UINT8 State */ + 0xfe, + /* UINT16 Reserved */ + 0x00, 0x00, + /* UINT32 Reserved1 */ + 0x00, 0x00, 0x00, 0x00, + /* AUTHENTICATED_VARIABLE_HEADER */ + /* UINT16 StartId */ + 0xaa, 0x55, + /* UINT8 State */ + 0x3f, + /* UINT8 Reserved */ + 0xff, + /* UINT32 Attributes */ + 0x07, 0x00, 0x00, 0x00, + /* UINT64 MonotonicCount */ + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + /* EFI_TIME TimeStamp */ + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, + /* UINT32 PubKeyIndex */ + 0xff, 0xff, 0xff, 0xff, + /* UINT32 NameSize */ + 0x12, 0x00, 0x00, 0x00, + /* UINT32 DataSize */ + 0x09, 0x00, 0x00, 0x00, + /* EFI_GUID VendorGuid */ + 0x1d, 0x4c, 0xae, 0xce, 0x5b, 0x33, 0x85, 0x46, 0xa4, 0xa0, 0xfc, 0x4a, + 0x94, 0xee, 0xa0, 0x85, + /* L"coreboot" */ + 0x63, 0x00, 0x6f, 0x00, 0x72, 0x00, 0x65, 0x00, 0x62, 0x00, + 0x6f, 0x00, 0x6f, 0x00, 0x74, 0x00, 0x00, 0x00, + /* "is great" */ + 0x69, 0x73, 0x20, 0x67, 0x72, 0x65, 0x61, 0x74, 0x00, +}; + +#define FVH_CHECKSUMMED_SIZE (sizeof(EFI_FIRMWARE_VOLUME_HEADER) + 8 + sizeof(EFI_GUID)) + +static struct region_device flash_rdev_rw; +static uint8_t flash_buffer[0x30000]; + +static const char *name = "coreboot"; + +static void mock_rdev(bool init) +{ + if (init) { + /* Emulate NOR flash by setting all bits to 1 */ + memset(flash_buffer, 0xff, sizeof(flash_buffer)); + /* Place _FVH and VIH headers, as well as test data */ + memcpy(flash_buffer, FVH, sizeof(FVH)); + } + + rdev_chain_mem_rw(&flash_rdev_rw, flash_buffer, sizeof(flash_buffer)); +} + +static const EFI_GUID EficorebootNvDataGuid = { + 0xceae4c1d, 0x335b, 0x4685, { 0xa4, 0xa0, 0xfc, 0x4a, 0x94, 0xee, 0xa0, 0x85 } }; + +/* Test valid and corrupted FVH header */ +static void efi_test_header(void **state) +{ + enum cb_err ret; + uint8_t buf[16]; + uint32_t size; + int i; + + mock_rdev(true); + + /* Test variable lookup with intact header */ + size = sizeof(buf); + ret = efi_fv_get_option(&flash_rdev_rw, &EficorebootNvDataGuid, name, buf, &size); + assert_int_equal(ret, CB_SUCCESS); + assert_int_equal(size, strlen("is great")+1); + assert_string_equal((const char *)buf, "is great"); + + for (i = 0; i < FVH_CHECKSUMMED_SIZE; i++) { + mock_rdev(true); + + /* Flip some bits */ + flash_buffer[i] ^= 0xff; + + size = sizeof(buf); + ret = efi_fv_get_option(&flash_rdev_rw, &EficorebootNvDataGuid, name, buf, + &size); + assert_int_not_equal(ret, CB_SUCCESS); + } +} + +/* Write with the same key and value should not modify the store */ +static void efi_test_noop_existing_write(void **state) +{ + enum cb_err ret; + int i; + + mock_rdev(true); + + ret = efi_fv_set_option(&flash_rdev_rw, + &EficorebootNvDataGuid, + name, + "is great", + strlen("is great") + 1); + + assert_int_equal(ret, CB_SUCCESS); + + for (i = sizeof(FVH); i < sizeof(flash_buffer); i++) + assert_int_equal(flash_buffer[i], 0xff); +} + +static void efi_test_new_write(void **state) +{ + enum cb_err ret; + uint8_t buf[16]; + uint32_t size; + int i; + + mock_rdev(true); + + ret = efi_fv_set_option(&flash_rdev_rw, &EficorebootNvDataGuid, + name, "is awesome", strlen("is awesome") + 1); + assert_int_equal(ret, CB_SUCCESS); + + /* New variable has been written */ + assert_int_equal(flash_buffer[ALIGN_UP(sizeof(FVH), 4)], 0xaa); + assert_int_equal(flash_buffer[ALIGN_UP(sizeof(FVH), 4) + 1], 0x55); + + /* Remaining space is blank */ + for (i = ALIGN_UP(sizeof(FVH), 4) + 89; i < sizeof(flash_buffer); i++) + assert_int_equal(flash_buffer[i], 0xff); + + mock_rdev(false); + + memset(buf, 0, sizeof(buf)); + size = sizeof(buf); + ret = efi_fv_get_option(&flash_rdev_rw, &EficorebootNvDataGuid, name, buf, + &size); + assert_int_equal(ret, CB_SUCCESS); + assert_int_equal(size, strlen("is awesome")+1); + + assert_int_equal(flash_buffer[ALIGN_UP(sizeof(FVH), 4) + 1], 0x55); + assert_string_equal((const char *)buf, "is awesome"); +} + +int main(void) +{ + const struct CMUnitTest tests[] = { + cmocka_unit_test(efi_test_header), + cmocka_unit_test(efi_test_noop_existing_write), + cmocka_unit_test(efi_test_new_write) + }; + + return cb_run_group_tests(tests, NULL, NULL); +} |