stm32f103-example VS bare-metal-echo

If you want to do bare-metal programming, you may want to take a look at my stm32f103-example project. It's for a different microcontroller than the one you're using, obviously, but converting it to work with an F4 part should be fairly straightforward. (I use the same framework for all of my STM32 projects.)

Use the CMSIS definitions of registers. They will save you a lot of time. If you're unhappy with having to repeat the names of peripherals, consider using something like the FIELD macros I wrote here.

The VECTOR macro expands to a sequence of assembler directives which uses .org. It'll end up creating gaps as needed.

And with a helper macro, you can rewrite the first bit as:

How can I go about debugging this error? All the code is on github (https://github.com/jonah-saltzman/bare-metal-echo), if anyone would be so kind as to take a look. The relevant code is in Src/init.c (where I set up the UART and DMA), and Src/io.c (the basic_transfer function is supposed to write to the serial output using DMA).

So I started with a udemy course, but I only watched about 30 minutes worth of it before I realized, to his credit, that the teacher was simply showing us what to look up in the technical reference manual. So basically I started really really simple (blinking an LED), then tried some timer stuff, then put that together into this project. I'm basically going peripheral-by-peripheral: first GPIO, then the NVIC interrupt controller + timers. I also did a console echo program with the UART, you can check that one out here. Next I'm going to learn DMA by combining DMA with UART to do IO without using the processor (as much).