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3 commits

Author SHA1 Message Date
Richard Henderson 3090c980ed hw/misc/bcm2835_rng: Use qemu_guest_getrandom_nofail
The random number is intended for use by the guest.  As such, we should
honor the -seed argument for reproducibility.  Use the *_nofail routine
instead of rolling our own error handling locally.

Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-05-22 12:38:54 -04:00
Peter Maydell 373442ea3a bcm2835_rng: Use qcrypto_random_bytes() rather than rand()
Switch to using qcrypto_random_bytes() rather than rand() as
our source of randomness for the BCM2835 RNG.

If qcrypto_random_bytes() fails, we don't want to return the guest a
non-random value in case they're really using it for cryptographic
purposes, so the best we can do is a fatal error.  This shouldn't
happen unless something's broken, though.

In theory we could implement this device's full FIFO and interrupt
semantics and then just stop filling the FIFO.  That's a lot of work,
though, and doesn't really give a very nice diagnostic to the user
since the guest will just seem to hang.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
2017-02-28 12:08:14 +00:00
Marcin Chojnacki 54a5ba13a9 target-arm: Implement BCM2835 hardware RNG
Recent vanilla Raspberry Pi kernels started to make use of
the hardware random number generator in BCM2835 SoC. As a
result, those kernels wouldn't work anymore under QEMU
but rather just freeze during the boot process.

This patch implements a trivial BCM2835 compatible RNG,
and adds it as a peripheral to BCM2835 platform, which
allows to boot a vanilla Raspberry Pi kernel under Qemu.

Changes since v1:
 * Prevented guest from writing [31..20] bits in rng_status
 * Removed redundant minimum_version_id_old
 * Added field entries for the state
 * Changed realize function to reset

Signed-off-by: Marcin Chojnacki <marcinch7@gmail.com>
Message-id: 20170210210857.47893-1-marcinch7@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-02-28 12:08:13 +00:00