EA5 Program Loader

[airernie]

I want to write a EA5 program loader in Assembly and hoping for a bit of guidance.  While I could leverage code from another application, I would prefer writing from scratch, so I fully understand the process.  I also don't want to rely on the internal EA loader so as to keep access to all of low memory.

 

It's not all that hard to read the program header, push it into memory, read the next program header, push it into memory, etc, then point the program counter the starting address of the program, but then what next?

 

So, if anyone is aware of any articles or sources that I could refer to I would appreciate it.

 

Thanks,

Ernie

[+Ksarul]

Good to see you back, Ernie! I think I have a couple of hardware things to send in your direction. . .there was a whole thread on EA5 loaders a few years ago that sought to (successfully) bypass some of the issues with the TI loader. It was an interesting community project that may give you some ideas as the source code was well documented.

[+jedimatt42]

Well, the way you 'point' the program counter is to use the branch instructions that sets the program counter and continues executing the code.

 

I would recommend looking at the code and comments in the 'scratchpad loader' on harmlesslion.com

[+jedimatt42]

http://harmlesslion.com/cgi-bin/onesoft.cgi?59

[Tursi]

Yeah. The EA#5 part of it is straight forward, but there are lots of gotchas in the DSRLNK part.

 

[airernie]

12 hours ago, Ksarul said:

there was a whole thread on EA5 loaders a few years ago that sought to (successfully) bypass some of the issues with the TI loader. It was an interesting community project that may give you some ideas as the source code was well documented.

Thanks All.. 

 

I'll do some more digging.  Just have to find the correct topic names..  Have a few other questions,  but the code should be helpful in answering them.

 

Happy computing..