I explored the options for the initial IDE to use:
1. Arduino: far too simple. Nice if all you want is a short, endless loop. But everything is preconfigured and runs out of the box.
2. ARM development IDE's: Either very expensive or Eclipse variants. Your only real choice is C or C++. Assembler is barely supported. And a minimal startup configuration is spread out over many header and source files. I spend about a day getting such a minimalist development environment together. The debugging works great.
3. Lazarus: far superior to Eclipse. I can use Pascal (but not assembler). And now with a new embedded platform choice! Well, I didn't get it to work yet, and I would have to make a new profile for my test CPUs, or use different ones. Spend a week or so researching and fixing that? I might get the compiling, linking and flashing to work using only command-line tools, but most info I could find seem to be outdated.
Decisions, decisions.
Anyway, it seems my best bet would be to translate the minimal C startup code to assembly, write an assembler/disassembler in assembly, a pascal compiler in pascal and have them compile themselves.