Christian Weisgerber:
> ccp(4) attaches, so presumably it is used as a source of entropy.
> Whether the hardware actually provides random output, I don't know.
I built a kernel with an instrumented driver. Unfortunately, no
entropy is provided:
ccp: rng 00000000
ccp: rng 00000000
ccp: rng 00000000
ccp: rng 00000000
ccp: rng 00000000
This is with the lastest firmware:
bios0: vendor coreboot version "v4.19.0.1" date 01/31/2023
Index: dev/ic/ccp.c
===================================================================
RCS file: /cvs/src/sys/dev/ic/ccp.c,v
retrieving revision 1.3
diff -u -p -r1.3 ccp.c
--- dev/ic/ccp.c 29 May 2020 04:42:25 -0000 1.3
+++ dev/ic/ccp.c 19 Apr 2023 15:12:17 -0000
@@ -56,6 +56,7 @@ ccp_rng(void *arg)
trng = bus_space_read_4(sc->sc_iot, sc->sc_ioh, CCP_REG_TRNG);
if (trng != 0)
enqueue_randomness(trng);
+ printf("ccp: rng %08x\n", trng);
- timeout_add_msec(&sc->sc_tick, 100);
+ timeout_add_msec(&sc->sc_tick, 5000);
}
--
Christian "naddy" Weisgerber [email protected]
