add UART-related TODO needed for compatibility with stock firmware

1 files changed, 2 insertions, 0 deletions

diff --git a/TODOs b/TODOs
index af2bf64..9143a9b 100644
--- a/TODOs
+++ b/TODOs
@@ -70,6 +70,8 @@ high priority TODOs are higher; low priority ones and completed ones are lower;
 
 * Check if setting user mode's sp and lr can be achieved by msr instead of switching to system mode. If so, use this method.
 
+* Explicitly select PL011 UART for communication on GPIO 14 & 15 (right now it is already selected when using rpi-open-firmware, but stock firmware on RPi 3 has miniUART there as default; perhaps this is all, that is needed to run the kernel under stock firmware). This is done with alternative function assignments - described in BCM2835 ARM Peripherals
+
 * partially DONE - one can always add more, but we have the most important stuff * Implement some basic utilities for us to use (memcpy, printf, etc...)
 
 * partailly DONE - svc works; once we implement processes we could also kill them on aborts * develop userspace process supervision (handling of interrupt caused by svc instruction, proper handling of other data abort, undefined instruction, etc.)