Rework of Initialization Chapter in BSP Howto

[Sebastian Huber]

On 05/02/2020 03:09, Chris Johns wrote:

> On 4/2/20 8:20 pm, Sebastian Huber wrote:
>> Hello,
>>
>> I reworked the heavily out dated system initialization chapter in the RTEMS BSP and Driver Guide:
>>
>> https://docs.rtems.org/branches/master/bsp-howto/initilization_code.html
>>
>> I would be happy if some want to review it.
> Looks good. I couple of comments ...
>
> 1. There is no discuss about boot loaders and the various role they play ...
>
>   Do all BSPs need a boot loader?
>   Can some BSP run directly from reset?
>   What set up is needed by a bootloader?
>
> Should there be some context here to guide a user in the area of boot loaders?

I am not sure, this guide is for BSP writers. They should know if there 
is a boot loader or not and what it does. I just mentioned a boot loader 
in one sentence:

"The low-level system initialization may depend on a platform initialization
carried out by a boot loader."

How a particular BSP boots should be documented in the user manual.

>
> 2. Minor edit?
>
>   and change into normal system mode with multi-threading enabled.
>
> to
>
>   and change into the normal system mode with multi-threading enabled.
I changed it.
>
> 3. 5.4 Should we highlight the handling of init errors are a system issue. I
> think it is important explain RTEMS does not manage system level issues for you
> and handling init errors is part of the system design. How does a user override
> a BSP default?

I think these questions should be answered by the Classic API Guide. A 
BSP writer just needs to know that initialization errors are fatal and 
the BSP should provide a fatal extension and a reset function.

The Classic API Guide could be improved to give an answer to "How does a 
user override a BSP default?":

https://docs.rtems.org/branches/master/c-user/fatal_error.html#announcing-a-fatal-error