arm64: zynqmp: Enable rng-seed generation

SOM has TPM with RNG in it that's why enable rng-seed generation.

Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Michal Simek <michal.simek@amd.com>
Link: https://lore.kernel.org/r/0e55eb3eade94e9cd0ffe04da0618aa6b1589f01.1751442246.git.michal.simek@amd.com

diff --git a/board/xilinx/common/board.c b/board/xilinx/common/board.c
index 8ffe742990168996b692d4471589f888356754a2..ceb58da6d3cd5258f588c0630c61aad974c879f4 100644 (file)
--- a/board/xilinx/common/board.c
+++ b/board/xilinx/common/board.c
@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0+
 /*
  * (C) Copyright 2014 - 2022, Xilinx, Inc.
- * (C) Copyright 2022 - 2023, Advanced Micro Devices, Inc.
+ * (C) Copyright 2022 - 2025, Advanced Micro Devices, Inc.
  *
  * Michal Simek <michal.simek@amd.com>
  */
@@ -712,3 +712,34 @@ phys_addr_t board_get_usable_ram_top(phys_size_t total_size)
 }
 
 #endif
+
+#if IS_ENABLED(CONFIG_BOARD_RNG_SEED)
+/* Use hardware rng to seed Linux random. */
+__weak int board_rng_seed(struct abuf *buf)
+{
+       struct udevice *dev;
+       ulong len = 64;
+       u64 *data;
+
+       if (uclass_get_device(UCLASS_RNG, 0, &dev) || !dev) {
+               printf("No RNG device\n");
+               return -ENODEV;
+       }
+
+       data = malloc(len);
+       if (!data) {
+               printf("Out of memory\n");
+               return -ENOMEM;
+       }
+
+       if (dm_rng_read(dev, data, len)) {
+               printf("Reading RNG failed\n");
+               free(data);
+               return -EIO;
+       }
+
+       abuf_init_set(buf, data, len);
+
+       return 0;
+}
+#endif

diff --git a/configs/xilinx_zynqmp_kria_defconfig b/configs/xilinx_zynqmp_kria_defconfig
index 22ba8a7cc1583b24cf79ed3b0bbf7699a5cc6280..3e2ac6144050ca84c571bed1864cee2fd72bc747 100644 (file)
--- a/configs/xilinx_zynqmp_kria_defconfig
+++ b/configs/xilinx_zynqmp_kria_defconfig
@@ -46,6 +46,7 @@ CONFIG_USE_PREBOOT=y
 CONFIG_SYS_PBSIZE=2073
 CONFIG_BOARD_EARLY_INIT_R=y
 CONFIG_CLOCKS=y
+CONFIG_BOARD_RNG_SEED=y
 CONFIG_SPL_MAX_SIZE=0x40000
 # CONFIG_SPL_BINMAN_SYMBOLS is not set
 # CONFIG_SPL_SHARES_INIT_SP_ADDR is not set