Re: [RFC PATCH v5 2/2] hw/riscv: sifive_u: Add backend drive support

[Bin Meng]

Hi Alistair,

On Thu, Oct 15, 2020 at 2:51 AM Alistair Francis <alistair23@gmail.com> wrote:
>
> On Wed, Oct 14, 2020 at 8:02 AM Bin Meng <bmeng.cn@gmail.com> wrote:
> >
> > Hi Alistair,
> >
> > On Wed, Oct 14, 2020 at 10:46 PM Alistair Francis <alistair23@gmail.com> 
> > wrote:
> > >
> > > On Wed, Sep 30, 2020 at 12:10 AM Green Wan <green.wan@sifive.com> wrote:
> > > >
> > > > On Wed, Sep 30, 2020 at 1:08 AM Alistair Francis <alistair23@gmail.com> 
> > > > wrote:
> > > > >
> > > > > On Mon, Sep 28, 2020 at 2:18 AM Green Wan <green.wan@sifive.com> 
> > > > > wrote:
> > > > > >
> > > > > > Hi Alistair,
> > > > > >
> > > > > > Thanks for the review. See the reply inline below.
> > > > > >
> > > > > >
> > > > > > On Sat, Sep 26, 2020 at 5:52 AM Alistair Francis 
> > > > > > <alistair23@gmail.com> wrote:
> > > > > > >
> > > > > > > On Tue, Sep 1, 2020 at 8:49 AM Green Wan <green.wan@sifive.com> 
> > > > > > > wrote:
> > > > > > > >
> > > > > > > > Add '-drive' support to OTP device. Allow users to assign a raw 
> > > > > > > > file
> > > > > > > > as OTP image.
> > > > > > >
> > > > > > > Do you mind writing an example command line argument in the 
> > > > > > > commit message?
> > > > > > >
> > > > > > > Also, do you have a test case for this? I would like to add it to 
> > > > > > > my CI.
> > > > > > >
> > > > > >
> > > > > > Do you mean qtest? I run uboot and use uboot driver to test it and
> > > > > > didn't create a qemu test case.
> > > > >
> > > > > No, I just mean how are you running and testing this.
> > > > >
> > > > > So you are booting U-Boot, then how do you test it in U-Boot?
> > >
> > > Hey,
> > >
> > > Sorry, this email didn't send and I only just noticed.
> > >
> > > >
> > > > Correct, I just enabled the configuration for
> > > > ./drivers/misc/sifive-otp.c in uboot for normal booting access to OTP.
> > > > And manually modify some failures write case to test write-once
> > > > feature.
> > >
> > > Can you document this? I would like to include this in my tests.
> > >
> >
> > See `QEMU Specific Instructions` in
> > https://github.com/riscv/opensbi/blob/master/docs/platform/sifive_fu540.md
>
> Hmm... I am missing something. I don't see any details on how you
> access the OTP and verify that reads/writes have occured. That link
> just seems to document how to build OpenSBI with a U-boot payload.
>
> Does U-Boot run the tests automatically after boot?

So far U-Boot only performs the OTP content read during boot, because
U-Boot needs to determine its MAC address based on the serial number
programmed in the OTP. In normal situations, U-Boot does not perform
any write to OTP. That's why I posted a U-Boot patch to test this QEMU
functionality of OTP write. The U-Boot patch is a shell command to
test the reading / writing of the OTP content. So what you need to do
to test this, is to follow the instructions documented in the OpenSBI
doc, then use my patch to test the OTP write.

Regards,
Bin