On Wed, Oct 16, 2024 at 4:22 AM Dragan Simic <dsi...@manjaro.org> wrote: > > Hello Alex, > > Thanks for the v5. Please see a few comments below. > > On 2024-10-15 23:28, Alex Shumsky wrote: > > Increase rng-seed size to make Linux happy and initialize rng pool > > instantly. > > Linux 5.19+ requires 32 bytes of entropy to initialize random pool, but > > u-boot > > currently provides only 8 bytes. > > Linux 5.18 and probably some versions before it used to require 64 > > bytes. > > Bump min value to 64 bytes to be on a safe side. > > > > Boot with 8 byte rng-seed (Linux 6.11): > > # dmesg | grep crng > > [ 12.089286] random: crng init done > > Boot with 32 byte rng-seed (Linux 6.11): > > # dmesg | grep crng > > [ 0.000000] random: crng init done > > > > Linux source references: > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/char/random.c?h=v5.19#n551 > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/char/random.c?h=v5.18#n236 > > > > Signed-off-by: Alex Shumsky <alexthr...@gmail.com> > > Fixes: d2048bafae40 ("rockchip: board: Add board_rng_seed() for all > > Rockchip devices") > > Reviewed-by: Dragan Simic <dsi...@manjaro.org> > > Reviewed-by: Marek Vasut <ma...@denx.de> > > --- > > > > Changes in v5: > > - add docs > > > > Changes in v4: > > - fix typos and code style > > > > Changes in v3: > > - reword warning > > - increase default rng_seed_size to support older linux as well > > - reword commit message > > > > Changes in v2: > > - add env config knob rng_seed_size > > - add warning for small rng_seed_size > > - 12-character commit SHA in Fixes > > > > arch/arm/mach-rockchip/board.c | 11 ++++++++++- > > common/Kconfig | 3 +++ > > doc/usage/environment.rst | 5 +++++ > > include/fdt_support.h | 3 ++- > > 4 files changed, 20 insertions(+), 2 deletions(-) > > > > diff --git a/arch/arm/mach-rockchip/board.c > > b/arch/arm/mach-rockchip/board.c > > index 3fadf7e412..ca6404776f 100644 > > --- a/arch/arm/mach-rockchip/board.c > > +++ b/arch/arm/mach-rockchip/board.c > > @@ -472,9 +472,18 @@ __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, 64); > > u64 *data; > > > > + if (len < 64) { > > + /* > > + * rng_seed_size should be at least 32 bytes for Linux 5.19+, > > + * or 64 for older Linux kernel versions > > + */ > > + log_warning("Value for rng_seed_size too low (%lu) and likely > > insufficient for the Linux RNG initialization\n", > > Please consider changing the message to: > > "Value for rng_seed_size (%lu) too low, Linux kernel RNG > may fail to initialize early\n" > > It's more compact, which is always good, and should be a bit > more precise that way. > > > + len); > > + } > > + > > data = malloc(len); > > if (!data) { > > printf("Out of memory\n"); > > diff --git a/common/Kconfig b/common/Kconfig > > index 957de0c5c0..c1d06f5045 100644 > > --- a/common/Kconfig > > +++ b/common/Kconfig > > @@ -927,6 +927,9 @@ config BOARD_RNG_SEED > > new seed for use on subsequent boots, and whether or not the > > kernel should account any entropy from the given seed. > > > > + Default seed size (64 bytes) can be overridden by a decimal > > environment > > + variable rng_seed_size. > > Maybe reflow a bit to follow the column width above. > > > + > > endmenu > > > > menu "Update support" > > diff --git a/doc/usage/environment.rst b/doc/usage/environment.rst > > index cc33d3ec0f..253b25a002 100644 > > --- a/doc/usage/environment.rst > > +++ b/doc/usage/environment.rst > > @@ -323,6 +323,11 @@ netretry > > Useful on scripts which control the retry operation > > themselves. > > > > +rng_seed_size > > + Size of random value added to device tree-node /chosen/rng-seed. > > + This variable is given as a hexadecimal number. > > We've come to a conclusion it's a decimal number, right? :) > So, please s/hexadecimal/decimal/ > > > + If unset, 64 bytes is used as the default. > > + > > silent_linux > > If set then Linux will be told to boot silently, by > > adding 'console=' to its command line. If "yes" it will be > > diff --git a/include/fdt_support.h b/include/fdt_support.h > > index 741e2360c2..02561eab15 100644 > > --- a/include/fdt_support.h > > +++ b/include/fdt_support.h > > @@ -202,7 +202,8 @@ int ft_board_setup(void *blob, struct bd_info *bd); > > * > > * This function is called if CONFIG_BOARD_RNG_SEED is set, and must > > * be provided by the board. It should return, via @buf, some suitable > > - * seed value to pass to the kernel. > > + * seed value to pass to the kernel. Seed size could be set in a > > decimal > > + * environment variable rng_seed_size and defaulted to 64 bytes. > > s/defaulted/it defaults/ >
Thanks, fixed. I'm not good at wording.
