From: Peter Maydell <peter.maydell@linaro.org>
To: James Hanley <jhanley@dgtlrift.com>
Cc: qemu-discuss <qemu-discuss@nongnu.org>,
qemu-arm <qemu-arm@nongnu.org>,
QEMU Developers <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] [Qemu-discuss] system_clock_scale unset in hw/intc/armv7m_nvic.c
Date: Fri, 13 Jan 2017 12:43:23 +0000 [thread overview]
Message-ID: <CAFEAcA87460MwQA2bjOxm-z6nfkNobQZC8X1qEFKZioWsznR3A@mail.gmail.com> (raw)
In-Reply-To: <CAF++6AOnuOzwiiPRJEGatzX7LuoJKU5ij2xWRLkKbxhytJscqA@mail.gmail.com>
On 13 January 2017 at 12:35, James Hanley <jhanley@dgtlrift.com> wrote:
> How should system_clock_scale be set in hw/intc/armv7m_nvic.c - there is no
> API for the global, and I've defaulted the global to SYSTICK_SCALE which
> seems to work, but is not obvious. This was needed as this value was set to
> zero and the arm firmware was selecting the external clock source causing
> zero to be returned from systick_scale() and the interrupt to run
> continuously.
If I recall correctly, this is an external-to-the-CPU thing
(wired up by the SoC or the board), which suggests that it
ought to be a property on the CPU object (or perhaps on a
currently-nonexistent container object which has the CPU
and the NVIC and the other M profile devices).
As the code stands today, I think the answer is that the
board has to set the global -- this is what stellaris.c does.
thanks
-- PMM
prev parent reply other threads:[~2017-01-13 12:43 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-13 12:35 [Qemu-devel] system_clock_scale unset in hw/intc/armv7m_nvic.c James Hanley
2017-01-13 12:43 ` Peter Maydell [this message]
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