Hi Vasile,

funlw65 wrote:
>>From my experience, a bootloader can be easily overwritten. Is easy to
> forget about compiler options when you work with various chips.

I have not much experience with bootloaders, only with the 
TinyBootlader. I have never overwritten it (except when I used a normal 
programmer), probably because its PC support program prevents it.

 > So you need a programmer at hand.

Yes, I would not want to do without one! Wisp648 and PicKit2 are Ok and 
not really expensive. So I don;t fear any bootloader because I can 
always reload it when it was erased or overwritten accidentally or on 
purpose.

> I'm thinking at this: maybe is a good idea to modify the compiler
> which came with development boards (Jaluino, Pinguino, FreeJALduino)
> so it will always compile outside of bootloader area. 

I may be an advantage that the compiler gives a message when the program 
  will not fit with bootloader. But do you want the compiler to know 
every bootloader? Seems not very practical to me.

There is another possibility.  Because most bootloaders (I know of) are 
located in high memory, and since program memory size is specified in 
the device files a change of the device file would do for these types of 
bootloaders.

Still I don't like this, certainly when dealing with different PICs and 
sometimes use a bootloader (or even different bootloaders) and sometimes 
not.

It might be better to have a compiler option (pragma) with which you 
could specify bootloader location and size.

There are more disadvantages of bootloaders, which are not so relevant 
in this discussion, but reason for me to avoid 'm.


[Matt:]
>> I know there are many serial port bootloaders available, but a jallib
>> bootloader would be nice for jallib & the tutorial doc. I would prefer
>> to use jalv2 to compile a bootloader.

I don't see any advantage in a bootloader written in Jal. It'll 
certainly take more memory then highly optimised ASM code (like Tiny 
Bootloader). And since it has only a single purpose nobody would want to 
change it (and make it even bigger than it already was). So what is the 
added value?   And then you need a support program on the PC too.

Regards, Rob.



-- 
Rob Hamerling, Vianen, NL (http://www.robh.nl/)

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