Hi Brandon,

You sure know how to make life difficult. Had you asked 
right away how to create a bootloader instead of how to 
relocate this and that I would have given totally 
different advice.

First, a bootloader that doesn't redirect the interrupt 
vectors runs the risk of selfdestruction. If power fails 
after erasure of the first block and before the reset 
vector is written back, your device is dead. This is not 
something I would want to distribute to my clients.

Second, after reading your wiki I think you would have 
accomplished the same thing with --code-loc for the 
bootloader and an added reset vector in asm in an 
ABSolute area with .org 0x0000.

My advice would be to use --code-loc to move the 
application and keep the bootloader at 0x0000. Add an 
assembly written interrupt redirection table to the 
bootloader and keep it free of interrupts itself. The 
cost is only a little latency on the interrupt service 
routines.

Greets,
Maarten


> Wiki page is at 
> http://sourceforge.net/apps/trac/sdcc/wiki/Compile%20and%20link%20a%20bootloader%20using%20SDCC
> 
> 
> On Feb 17, 2010, at 16:34 , Brandon Fosdick wrote:
> 
> > I've had a request to add a writeup of my bootloader adventure to the 
> > project wiki. Hopefully I'll get to it this weekend. I don't see a How-To 
> > section on the front wiki page, anyone mind if I add it?
> > 
> > In case anyone is curious, or I'm too lazy to actually do the wiki bits, 
> > here's the gist I made with the relevant crtstart.asm and Makefile: 
> > http://gist.github.com/304594


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