#customboard #defconfig #supervisormode #customboard #defconfig #supervisormode
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sathya281@...
Hi, Is there a way to run zephyr only in user/machine mode ? Please let me know note: I am new to zephyr os.
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Mani Sadhasivam
Hi Sathya,
Which SoC are you trying with? AFAIK all supported SoC's only incorporate Machine mode access, not even User mode. Supervisor mode is meant for a full-fledged operating system. Thanks, Mani
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sathya281@...
Hi Zephyr supports supervisor mode. I want to nullify it at software level. corresponding dts , we are using is "riscv32-qemu.dtsi" regards, sathya
On Wed, Oct 17, 2018 at 1:11 PM Mani Sadhasivam <manivannanece23@...> wrote:
--
regards,
Sathya
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Mani Sadhasivam
Where did you find this information? For RISC-V SoCs, the supervisor mode is only used when the base architecture has the 'S' extension. Since there is no Supervisor enabled SoCs supported by Zephyr so far, the core RISC-V code doesn't care about it. This applies to QEMU also. -Mani
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Boie, Andrew P
Hi,
User mode is currently only supported on x86, ARM, and ARC CPUs. The documentation uses "supervisor mode" to refer to non-user mode, i.e. all CPU instructions may be executed and all memory may be touched. It seems to be the case that this collides with some RISC-V specific term?
More information: https://docs.zephyrproject.org/latest/kernel/usermode/usermode.html
HTH, Andrew
From: users@... [mailto:users@...]
On Behalf Of Mani Sadhasivam
Sent: Wednesday, October 17, 2018 3:00 AM To: users@... Subject: Re: [Zephyr-users] #customboard #defconfig #supervisormode
Where did you find this information? For RISC-V SoCs, the supervisor mode is only used
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Sathya Narayanan N <sathya281@...>
Thanks. Actually I want to remove any supervisor mode access in the code. We don't want to have mmu. We want to run in user/machine mode.
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I got your point on usermode. Is there a way I can turn off mmu/ supervisor mode. And run in machine mode. The riscv32 hardware, we are running doesn't support mmu or supervisor mode. We want to run zephyr on it. I am looking for some flag kind of thing, that can turn off mmu/supervisor mode. Please suggest.
On Thursday, October 18, 2018, Boie, Andrew P <andrew.p.boie@...> wrote: > Hi, > > > > User mode is currently only supported on x86, ARM, and ARC CPUs. > > The documentation uses "supervisor mode" to refer to non-user mode, i.e. all CPU instructions may be executed and all memory may be touched. > > It seems to be the case that this collides with some RISC-V specific term? > > > > More information: https://docs.zephyrproject.org/latest/kernel/usermode/usermode.html > > > > HTH, > > Andrew > > > > From: users@... [mailto:users@...] On Behalf Of Mani Sadhasivam > Sent: Wednesday, October 17, 2018 3:00 AM > To: users@... > Subject: Re: [Zephyr-users] #customboard #defconfig #supervisormode > > > > Zephyr supports supervisor mode. I want to nullify it at software level. > > Where did you find this information? For RISC-V SoCs, the supervisor mode is only used > when the base architecture has the 'S' extension. Since there is no Supervisor enabled > SoCs supported by Zephyr so far, the core RISC-V code doesn't care about it. > > This applies to QEMU also. > > -Mani > -- regards,
Sathya
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Mani Sadhasivam
That's right! In RISC-V terms, Machine mode has access to all system resources and is the
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Boie, Andrew P
We are talking past each other. What is your definition of "user mode"? I don't think we are using the same terminology. I don't know what you mean by "machine mode". You can't have the entire kernel run in user mode, you wouldn't be able to lock IRQs or do lots of other things. The MMU is not enabled at all in the Risc-V port. My feeling here is that no action needs to be taken.
Andrew
From: Sathya Narayanan N [mailto:sathya281@...]
Sent: Wednesday, October 17, 2018 9:32 PM To: Boie, Andrew P <andrew.p.boie@...> Cc: Mani Sadhasivam <manivannanece23@...>; users@... Subject: Re: [Zephyr-users] #customboard #defconfig #supervisormode
Thanks. Actually I want to remove any supervisor mode access in the code. We don't want to have mmu. We want to run in user/machine mode.
regards,
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Boie, Andrew P
What RISC-V calls "machine mode" is what the Zephyr documentation refers to as "supervisor" or "privileged" mode. You don't need to do anything.
Andrew
From: users@... [mailto:users@...]
On Behalf Of Mani Sadhasivam
Sent: Wednesday, October 17, 2018 9:46 PM To: users@... Subject: Re: [Zephyr-users] #customboard #defconfig #supervisormode
That's right! In RISC-V terms, Machine mode has access to all system resources and is the
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Sathya Narayanan N <sathya281@...>
Hi Andrew,
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Thanks a lot. Sorry for the trouble.
On Thursday, October 18, 2018, Boie, Andrew P <andrew.p.boie@...> wrote: > What RISC-V calls "machine mode" is what the Zephyr documentation refers to as "supervisor" or "privileged" mode. > > You don't need to do anything. > > > > Andrew > > > > From: users@... [mailto:users@...] On Behalf Of Mani Sadhasivam > Sent: Wednesday, October 17, 2018 9:46 PM > To: users@... > Subject: Re: [Zephyr-users] #customboard #defconfig #supervisormode > > > > It seems to be the case that this collides with some RISC-V specific term? > > That's right! In RISC-V terms, Machine mode has access to all system resources and is the > mandatory mode to implement. Supervisor mode has a different usage model, which I guess > used for virtualization. > -- regards,
Sathya
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Jean-Paul Etienne
Hi Sathya, Zephyr for riscv runs only in machine mode. All threads execute in machine mode. Regards, Jean-Paul
On Thu, Oct 18, 2018 at 6:31 AM Sathya Narayanan N <sathya281@...> wrote: Thanks. Actually I want to remove any supervisor mode access in the code. We don't want to have mmu. We want to run in user/machine mode.
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Sathya Narayanan N <sathya281@...>
@all Thanks a lot for your support. Thanks Jean !
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On Friday, October 19, 2018, Jean-Paul Etienne <fractalclone@...> wrote:
-- regards,
Sathya
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