Re: [ECOS] small custom bootloader to start an app stored in flash

[Oleg Uzenkov <o.uzenkov@unicore.co.ua>]

Hi,

I agree!

Redboot is a great piece of software. It is just I found that when you 
enable some important features like FIS support, Redboot reserves extra 
space in RAM memory.
The size of this reserved extra space in RAM equals to the size of the 
largest section size in Flash. In case of stm32f407 it is 128KB. 
Internal RAM is 128KB. As John Dallaway pointed out there is very little 
sense in using Redboot without enough of external RAM on stm32f4 
devices. For example for Kinetis it is a different story, the flash 
sections are uniform and quite small.

For small systems external RAM chip significantly adds up to the cost of 
a device.

Best wishes,
Oleg
> On Thu, 23 Oct 2014, Oleg Uzenkov wrote:
>
>> At last got some progress! :-)
> Congrats!
>
> [snip]
>
>>    HAL_PLF_ARCH_GETRESETVECTOR(exec, 0x08020000);
>                                             ^^^^^
> Oleg, you reserve 128K for "small custom bootloader", 128K is more than
> enough to use RedBoot. If you can donate 128K for boot-loader then use
> RedBoot.  I am sure that RedBoot can run and your "ROMROM" applications.
> If standard RedBoot lacks some behaviors, just provide new functionality
> with custom RedBoot command(s) FYI: this code can be part platform HAL.
>
> Paraphrasing  Greenspun's Tenth Rule, Any custom boot-loader for eCos
> will contain an ad hoc, informally-specified, bug-ridden, implementation
> of half of RedBoot :-)
>
> I assure you if you can donate 128K for your own bootstrap code then
> using RedBoot will save your time and efforts.
>
> Sergei
>


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