Hello Alex,

Thanks for the v2. Please see a few comments below.

On 2024-10-14 19:53, Alex Shumsky wrote:

Modern Linux requires 32 byte seed to initialize random pool, but u-boot currently provides only 8 bytes. Increase rng-seed size to make Linux happy and initialize rng pool instantly.

Boot with 8 byte rng-seed: # dmesg | grep crng [ 12.089286] random: crng init done Boot with 32 byte rng-seed: # dmesg | grep crng [ 0.000000] random: crng init done

https://github.com/torvalds/linux/blob/7234e2ea0edd00bfb6bb2159e55878c19885c...

Signed-off-by: Alex Shumsky alexthreed@gmail.com Fixes: d2048bafae40 ("rockchip: board: Add board_rng_seed() for all Rockchip devices")

---

Changes in v2:

• add env config knob rng_seed_size

Perhaps the emitted warning should also be mentioned here.

• 12-character commit SHA in Fixes

arch/arm/mach-rockchip/board.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-rockchip/board.c b/arch/arm/mach-rockchip/board.c index 3fadf7e412..f9f0d7214c 100644 --- a/arch/arm/mach-rockchip/board.c +++ b/arch/arm/mach-rockchip/board.c @@ -472,9 +472,15 @@ __weak int misc_init_r(void) __weak int board_rng_seed(struct abuf *buf) { struct udevice *dev;

• size_t len = 0x8;

• ulong len = env_get_ulong("rng_seed_size", 10, 32); u64 *data;

• if (len < 32) {

• // rng_seed_size should be 32 bytes for Linux 5.19+, or 64 for older 
  

Linux'es

Shouldn't it be 8 for older kernels?

• log_warning("Too small rng_seed_size (%lu). It is likely
  

insufficient to init linux crng\n",

• 	    len);
  

Perhaps this would read better:

"Value for rng_seed_size too low (%lu) and likely insufficient for the Linux RNG initialization"

• }
• data = malloc(len); if (!data) { printf("Out of memory\n");