notes.txt

openocd fill look for openocd.cfg file by default, then in its directories
stm32f091rc embeds stlink v2-1, not v2
    (using v2's cfg file raises 'error: open failed')
^ really? openocd says that stlink version v2
but in user manual its fucking v2-1

base:
Cortex-M0 Devices Generic User Guide, 2.1.3: Core registers #CONTROL register
info:

asm: add thumb_func before thumb function! wwdg otherwise

calling a function changes the stack and because of it i couldnt return
to my previous stack frame when i started the os by calling tcb->handler()
(probably)

use stmdb in context switch, cause nvic pushes stackframe and then
leaves SP at r0, lowest address. using stmia would corrupt that stackframe

spi: clock, despite being set to be 0 at idle and no push-down
nor pull-up resistor, its 1 at idle. idk why, ill conform to it and set it to be 1 at idle + set a push-up resistor

Copmiler it wth -std=c99 cause CMSIS libraries do not support ANSI C stndard

before return from sd init, use ACMD42 as specified on p.28 PhysLayerSimpSpec