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Re: [Qemu-devel] Testing sysbus devices
From: |
Markus Armbruster |
Subject: |
Re: [Qemu-devel] Testing sysbus devices |
Date: |
Tue, 19 Feb 2019 18:55:39 +0100 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) |
Stephen Checkoway <address@hidden> writes:
>> On Feb 19, 2019, at 10:28, Markus Armbruster <address@hidden> wrote:
>>
>> My terminology might be confused...
>>
>> Let me backtrack a bit an explain my use case. On physical PCs, the
>> single flash chip is commonly configured to have a read-only part and a
>> read/write part. The read-only part holds UEFI code, and the read-write
>> part holds its persistent state.
>>
>> Since our virtual flash chips lack this feature, our virtual PCs have
>> *two* of them: one configured read-only, and one configured read/write.
>> Cleaning that up would be nice.
>>
>> The comment "It does not implement software data protection as found in
>> many real chips" in both pflash_cfi0*.c might be referring to this
>> missing feature.
>
> I understand now, thank you for explaining. I noticed the comments about
> software data protection in the code, but I didn't investigate.
>
>>From a quick look at <https://www.cypress.com/file/195291/download> Table 27
>>on page 8, I see there are at least 4 different protection modes. I think the
>>most common one (based on my reading of a handful of data sheets for flash
>>chips) is the high voltage one. Essentially, there are sector groups that can
>>be locked/unlocked using high voltage. It seems easy enough to model this by
>>configuring sectors as locked and refusing to erase or program them.
>
> Software command locking would probably involve implementing a few additional
> commands.
>
> I'm not sure what the others are.
>
> Which locking method do you need?
László, Philippe, what would you prefer to work with in OVMF?
- [Qemu-devel] Testing sysbus devices, Stephen Checkoway, 2019/02/18
- Re: [Qemu-devel] Testing sysbus devices, Thomas Huth, 2019/02/18
- Re: [Qemu-devel] Testing sysbus devices, Stephen Checkoway, 2019/02/18
- Re: [Qemu-devel] Testing sysbus devices, Thomas Huth, 2019/02/18
- Re: [Qemu-devel] Testing sysbus devices, Markus Armbruster, 2019/02/18
- Re: [Qemu-devel] Testing sysbus devices, Stephen Checkoway, 2019/02/18
- Re: [Qemu-devel] Testing sysbus devices, Markus Armbruster, 2019/02/19
- Re: [Qemu-devel] Testing sysbus devices, Stephen Checkoway, 2019/02/19
- Re: [Qemu-devel] Testing sysbus devices, Markus Armbruster, 2019/02/19
- Re: [Qemu-devel] Testing sysbus devices, Stephen Checkoway, 2019/02/19
- Re: [Qemu-devel] Testing sysbus devices,
Markus Armbruster <=
- Re: [Qemu-devel] Testing sysbus devices, Laszlo Ersek, 2019/02/20
- Re: [Qemu-devel] Testing sysbus devices, Markus Armbruster, 2019/02/20
- Re: [Qemu-devel] Testing sysbus devices, Stephen Checkoway, 2019/02/21
- Re: [Qemu-devel] Testing sysbus devices, Markus Armbruster, 2019/02/22
- Re: [Qemu-devel] Testing sysbus devices, Laszlo Ersek, 2019/02/22
- Re: [Qemu-devel] Testing sysbus devices, Stephen Checkoway, 2019/02/22
- Re: [Qemu-devel] Testing sysbus devices, Laszlo Ersek, 2019/02/22
- Re: [Qemu-devel] Testing sysbus devices, Stephen Checkoway, 2019/02/22