small custom bootloader to start an app stored in flash

[Oleg Uzenkov <o dot uzenkov at unicore dot co dot ua>]

Hello Everyone,

I would like to make a small custom bootloader (not considering RedBoot) 
that would implement a simple function of checking a flag (some bytes in 
memory) and then jumping to one of the applications stored in internal 
flash.

Something like this:

internal flash memory:

------------------  0x08000000
| bootloader  |
|                    |
------------------
|_____            |
|flag |            |
------------------
|                    |
|                    |
------------------
| app1           |
|                    |
------------------
| app2           |
|                    |
------------------
|                    |
|                    |
--------------

Basically, if flag is true then start app1 else start app2.

I suppose bootloader would be a simple eCos app with ROM startup. 
Applications in flash probably should also be built for ROM startup.
When the jump is made app's .data and .bss sections should be copied 
into RAM...

Any ideas how to make a jump to start an app? May be some sample code 
showing how to do it in eCos? May be someone has done it already?

I would appreciate any help on this.

Best wishes,

Oleg

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