1 files changed, 179 insertions, 0 deletions
diff --git a/roms/u-boot/lib/efi_loader/efi_rng.c b/roms/u-boot/lib/efi_loader/efi_rng.c
new file mode 100644
index 000000000..0e0654685
--- /dev/null
+++ b/roms/u-boot/lib/efi_loader/efi_rng.c
@@ -0,0 +1,179 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2019, Linaro Limited
+ */
+
+#define LOG_CATEGORY LOGC_EFI
+
+#include <common.h>
+#include <dm.h>
+#include <efi_loader.h>
+#include <efi_rng.h>
+#include <log.h>
+#include <rng.h>
+#include <asm/global_data.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+const efi_guid_t efi_guid_rng_protocol = EFI_RNG_PROTOCOL_GUID;
+
+/**
+ * platform_get_rng_device() - retrieve random number generator
+ *
+ * This function retrieves the udevice implementing a hardware random
+ * number generator.
+ *
+ * This function may be overridden if special initialization is needed.
+ *
+ * @dev:	udevice
+ * Return:	status code
+ */
+__weak efi_status_t platform_get_rng_device(struct udevice **dev)
+{
+	int ret;
+	struct udevice *devp;
+
+	ret = uclass_get_device(UCLASS_RNG, 0, &devp);
+	if (ret) {
+		debug("Unable to get rng device\n");
+		return EFI_DEVICE_ERROR;
+	}
+
+	*dev = devp;
+
+	return EFI_SUCCESS;
+}
+
+/**
+ * rng_getinfo() - get information about random number generation
+ *
+ * This function implement the GetInfo() service of the EFI random number
+ * generator protocol. See the UEFI spec for details.
+ *
+ * @this:			random number generator protocol instance
+ * @rng_algorithm_list_size:	number of random number generation algorithms
+ * @rng_algorithm_list:		descriptions of random number generation
+ *				algorithms
+ * Return:			status code
+ */
+static efi_status_t EFIAPI rng_getinfo(struct efi_rng_protocol *this,
+				       efi_uintn_t *rng_algorithm_list_size,
+				       efi_guid_t *rng_algorithm_list)
+{
+	efi_status_t ret = EFI_SUCCESS;
+	efi_guid_t rng_algo_guid = EFI_RNG_ALGORITHM_RAW;
+
+	EFI_ENTRY("%p, %p, %p", this, rng_algorithm_list_size,
+		  rng_algorithm_list);
+
+	if (!this || !rng_algorithm_list_size) {
+		ret = EFI_INVALID_PARAMETER;
+		goto back;
+	}
+
+	if (!rng_algorithm_list ||
+	    *rng_algorithm_list_size < sizeof(*rng_algorithm_list)) {
+		*rng_algorithm_list_size = sizeof(*rng_algorithm_list);
+		ret = EFI_BUFFER_TOO_SMALL;
+		goto back;
+	}
+
+	/*
+	 * For now, use EFI_RNG_ALGORITHM_RAW as the default
+	 * algorithm. If a new algorithm gets added in the
+	 * future through a Kconfig, rng_algo_guid will be set
+	 * based on that Kconfig option
+	 */
+	*rng_algorithm_list_size = sizeof(*rng_algorithm_list);
+	guidcpy(rng_algorithm_list, &rng_algo_guid);
+
+back:
+	return EFI_EXIT(ret);
+}
+
+/**
+ * rng_getrng() - get random value
+ *
+ * This function implement the GetRng() service of the EFI random number
+ * generator protocol. See the UEFI spec for details.
+ *
+ * @this:		random number generator protocol instance
+ * @rng_algorithm:	random number generation algorithm
+ * @rng_value_length:	number of random bytes to generate, buffer length
+ * @rng_value:		buffer to receive random bytes
+ * Return:		status code
+ */
+static efi_status_t EFIAPI getrng(struct efi_rng_protocol *this,
+				  efi_guid_t *rng_algorithm,
+				  efi_uintn_t rng_value_length,
+				  uint8_t *rng_value)
+{
+	int ret;
+	efi_status_t status = EFI_SUCCESS;
+	struct udevice *dev;
+	const efi_guid_t rng_raw_guid = EFI_RNG_ALGORITHM_RAW;
+
+	EFI_ENTRY("%p, %p, %zu, %p", this, rng_algorithm, rng_value_length,
+		  rng_value);
+
+	if (!this || !rng_value || !rng_value_length) {
+		status = EFI_INVALID_PARAMETER;
+		goto back;
+	}
+
+	if (rng_algorithm) {
+		EFI_PRINT("RNG algorithm %pUl\n", rng_algorithm);
+		if (guidcmp(rng_algorithm, &rng_raw_guid)) {
+			status = EFI_UNSUPPORTED;
+			goto back;
+		}
+	}
+
+	ret = platform_get_rng_device(&dev);
+	if (ret != EFI_SUCCESS) {
+		EFI_PRINT("Rng device not found\n");
+		status = EFI_UNSUPPORTED;
+		goto back;
+	}
+
+	ret = dm_rng_read(dev, rng_value, rng_value_length);
+	if (ret < 0) {
+		EFI_PRINT("Rng device read failed\n");
+		status = EFI_DEVICE_ERROR;
+		goto back;
+	}
+
+back:
+	return EFI_EXIT(status);
+}
+
+static const struct efi_rng_protocol efi_rng_protocol = {
+	.get_info = rng_getinfo,
+	.get_rng = getrng,
+};
+
+/**
+ * efi_rng_register() - register EFI_RNG_PROTOCOL
+ *
+ * If a RNG device is available, the Random Number Generator Protocol is
+ * registered.
+ *
+ * Return:	An error status is only returned if adding the protocol fails.
+ */
+efi_status_t efi_rng_register(void)
+{
+	efi_status_t ret;
+	struct udevice *dev;
+
+	ret = platform_get_rng_device(&dev);
+	if (ret != EFI_SUCCESS) {
+		log_warning("Missing RNG device for EFI_RNG_PROTOCOL\n");
+		return EFI_SUCCESS;
+	}
+	ret = efi_add_protocol(efi_root, &efi_guid_rng_protocol,
+			       (void *)&efi_rng_protocol);
+	if (ret != EFI_SUCCESS)
+		log_err("Cannot install EFI_RNG_PROTOCOL\n");
+
+	return ret;
+}