Messages in this thread Patch in this message | | | From | Hsin-Yi Wang <> | Subject | [PATCH v7 2/3] fdt: add support for rng-seed | Date | Wed, 3 Jul 2019 12:01:37 +0800 |
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Introducing a chosen node, rng-seed, which is an entropy that can be passed to kernel called very early to increase initial device randomness. Bootloader should provide this entropy and the value is read from /chosen/rng-seed in DT.
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Reviewed-by: Rob Herring <robh@kernel.org> --- No change since v6. --- drivers/of/fdt.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index cd17dc62a719..7be50e287ba6 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -24,6 +24,7 @@ #include <linux/debugfs.h> #include <linux/serial_core.h> #include <linux/sysfs.h> +#include <linux/random.h> #include <asm/setup.h> /* for COMMAND_LINE_SIZE */ #include <asm/page.h> @@ -1043,6 +1044,7 @@ int __init early_init_dt_scan_chosen(unsigned long node, const char *uname, { int l; const char *p; + const void *rng_seed; pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname); @@ -1077,6 +1079,14 @@ int __init early_init_dt_scan_chosen(unsigned long node, const char *uname, pr_debug("Command line is: %s\n", (char*)data); + rng_seed = of_get_flat_dt_prop(node, "rng-seed", &l); + if (rng_seed && l > 0) { + add_device_randomness(rng_seed, l); + + /* try to clear seed so it won't be found. */ + fdt_nop_property(initial_boot_params, node, "rng-seed"); + } + /* break now */ return 1; } -- 2.20.1
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