Does anyone have any advice for learning how to program Cortex-M processors without an IDE?

I'm interested in learning about what's under the hood, or what's hidden from you by an IDE, by which I mean, compiler, linker, makefiles - that type of thing. I have a few specific, if potentially misguided...
Does anyone have any advice for learning how to program Cortex-M processors without an IDE?

I'm interested in learning about what's under the hood, or what's hidden from you by an IDE, by which I mean, compiler, linker, makefiles - that type of thing. I have a few specific, if potentially misguided...
ARM Processors ANY MODEL CORE on die

Can someone tell me whether its relatively straightforward for a reverse engineer to identify an ARM CPU CORE on die ? Can the (IC) CORE be carefully camouflaged or hidden on die from companies that try...
any free compilers of ARM9 processor available???

hi friends if there are any free compilers and debuggers available on net for ARM9 processors , then please tell me. Thanks in advance kaushik
any free compilers of ARM9 processor available???

hi friends if there are any free compilers and debuggers available on net for ARM9 processors , then please tell me. Thanks in advance kaushik