I have a question about OKL4 code

[Josh Zhao]

hi , I m reading the OKL4 version 2.1 for armv5 code, i have a qestion that the idle kernel thread creates the root server thread,but its handler function(initial_to_user) do nothing:
         BEGIN_PROC(initial_to_user)
        SET_USER_DACR
        RESTORE_ALL
        subs    pc,     lr,     #1
        END_PROC(initial_to_user)

it seems run forever, because there is no thread except idle. So how I create /delete other threads based L4?

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[Gabi Voiculescu]

I think (but am not sure) that this function is only supposed to change cpu mode from SVC (supervisor) to USER.

Somebody please correct me if i'm wrong.
Gabi Voiculescu

--- On Sat, 10/17/09, Josh Zhao <[hidden email]> wrote:

From: Josh Zhao <[hidden email]>
Subject: [okl4-developer] I have a question about OKL4 code
To: [hidden email]
Date: Saturday, October 17, 2009, 12:13 PM

hi , I m reading the OKL4 version 2.1 for armv5 code, i have a qestion that the idle kernel thread creates the root server thread,but its handler function(initial_to_user) do nothing:
         BEGIN_PROC(initial_to_user)
        SET_USER_DACR
        RESTORE_ALL
        subs    pc,     lr,     #1
        END_PROC(initial_to_user)

it seems run forever, because there is no thread except idle. So how I create /delete other threads based L4?

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[Josh Zhao]

yes, the root server will set the inital stack up with user mode,but there is no code in user mode.so I don't understand what it is used for.

2009/10/17 Gabi Voiculescu <[hidden email]>

I think (but am not sure) that this function is only supposed to change cpu mode from SVC (supervisor) to USER.

Somebody please correct me if i'm wrong.
Gabi Voiculescu

--- On Sat, 10/17/09, Josh Zhao <[hidden email]> wrote:

From: Josh Zhao <[hidden email]>
Subject: [okl4-developer] I have a question about OKL4 code
To: [hidden email]
Date: Saturday, October 17, 2009, 12:13 PM

hi , I m reading the OKL4 version 2.1 for armv5 code, i have a qestion that the idle kernel thread creates the root server thread,but its handler function(initial_to_user) do nothing:
         BEGIN_PROC(initial_to_user)
        SET_USER_DACR
        RESTORE_ALL
        subs    pc,     lr,     #1
        END_PROC(initial_to_user)

it seems run forever, because there is no thread except idle. So how I create /delete other threads based L4?

-----Inline Attachment Follows-----

_______________________________________________
Developer mailing list
Developer@...
https://lists.okl4.org/mailman/listinfo/developer

_______________________________________________
Developer mailing list
[hidden email]
https://lists.okl4.org/mailman/listinfo/developer

[Gabi Voiculescu]

Hmmm.

I google searched for your problem and found that the way it was supposed to work is:

- the stack should be set up in crt0.spp under arch/arm/libs/c/crt (maybe this is the code you need)
- after initial_to_user the system should go to _start in the rootserver

I hope this helps. And if it does, a reply to clarify what was your problem and how you fixed it might help the community :;.

I guess I should thank you too since this search pointed me to something that might explain why I get qemu: fatal: bad mode 0 in my board emulator..

Gabi Voiculescu

--- On Sat, 10/17/09, Josh Zhao <[hidden email]> wrote:

From: Josh Zhao <[hidden email]>
Subject: Re: [okl4-developer] I have a question about OKL4 code
To: "Gabi Voiculescu" <[hidden email]>
Cc: [hidden email]
Date: Saturday, October 17, 2009, 2:39 PM

yes, the root server will set the inital stack up with user mode,but there is no code in user mode.so I don't understand what it is used for.

2009/10/17 Gabi Voiculescu <boy3dfx2@...>

I think (but am not sure) that this function is only supposed to change cpu mode from SVC (supervisor) to USER.

Somebody please correct me if i'm wrong.
Gabi Voiculescu

--- On Sat, 10/17/09, Josh Zhao <joshsystem@...> wrote:

From: Josh Zhao <joshsystem@...>
Subject: [okl4-developer] I have a question about OKL4 code
To: developer@...
Date: Saturday, October 17, 2009, 12:13 PM

hi , I m reading the OKL4 version 2.1 for armv5 code, i have a qestion that the idle kernel thread creates the root server thread,but its handler function(initial_to_user) do nothing:
         BEGIN_PROC(initial_to_user)
        SET_USER_DACR
        RESTORE_ALL
        subs    pc,     lr,     #1
        END_PROC(initial_to_user)

it seems run forever, because there is no thread except idle. So how I create /delete other threads based L4?

-----Inline Attachment Follows-----

_______________________________________________
Developer mailing list
Developer@...
https://lists.okl4.org/mailman/listinfo/developer

_______________________________________________
Developer mailing list
[hidden email]
https://lists.okl4.org/mailman/listinfo/developer

[Josh Zhao]

Thanks Gabi, I m new to OKL4,I really want to know how kernel works.For me,reading source code is a good approach. Following your reply,I have another question:
   The crt0.spp is only wrapper that initilizes the __sys_init(),so how does initial_to_user function jump to crt0.spp ?

2009/10/17 Gabi Voiculescu <[hidden email]>

Hmmm.

I google searched for your problem and found that the way it was supposed to work is:

- the stack should be set up in crt0.spp under arch/arm/libs/c/crt (maybe this is the code you need)
- after initial_to_user the system should go to _start in the rootserver

I hope this helps. And if it does, a reply to clarify what was your problem and how you fixed it might help the community :;.

I guess I should thank you too since this search pointed me to something that might explain why I get qemu: fatal: bad mode 0 in my board emulator..

Gabi Voiculescu

--- On Sat, 10/17/09, Josh Zhao <[hidden email]> wrote:

From: Josh Zhao <[hidden email]>

Subject: Re: [okl4-developer] I have a question about OKL4 code
To: "Gabi Voiculescu" <[hidden email]>
Cc: [hidden email]
Date: Saturday, October 17, 2009, 2:39 PM

yes, the root server will set the inital stack up with user mode,but there is no code in user mode.so I don't understand what it is used for.

2009/10/17 Gabi Voiculescu <boy3dfx2@...>

I think (but am not sure) that this function is only supposed to change cpu mode from SVC (supervisor) to USER.

Somebody please correct me if i'm wrong.
Gabi Voiculescu

--- On Sat, 10/17/09, Josh Zhao <joshsystem@...> wrote:

From: Josh Zhao <joshsystem@...>
Subject: [okl4-developer] I have a question about OKL4 code
To: developer@...
Date: Saturday, October 17, 2009, 12:13 PM

hi , I m reading the OKL4 version 2.1 for armv5 code, i have a qestion that the idle kernel thread creates the root server thread,but its handler function(initial_to_user) do nothing:
         BEGIN_PROC(initial_to_user)
        SET_USER_DACR
        RESTORE_ALL
        subs    pc,     lr,     #1
        END_PROC(initial_to_user)

it seems run forever, because there is no thread except idle. So how I create /delete other threads based L4?

-----Inline Attachment Follows-----

_______________________________________________
Developer mailing list
Developer@...
https://lists.okl4.org/mailman/listinfo/developer

_______________________________________________
Developer mailing list
[hidden email]
https://lists.okl4.org/mailman/listinfo/developer