TODO.txt

Things that still need doing:

• finish ARP layer
 - in net/arp
 - add reply functionality
 - add request functionality
 - allow tasks to block on waiting for an address to be populated (should have timeout too)

• add ICMP layer

• add IGMP layer?
 - we may not need this
 - if there's no routing between hosts, we don't need IGMP to create the multicast routes

• add simple networking stack
 - reference implementation (or usable in most cases)
 - socket router <--> UDP router <--> IPv4 router <--> Ethernet layer
                             ICMP <--/
 - can add a device below the stack that handles layer 1

• finish NIC driver
 - Wiznet W5500 chip
 - mostly care about using Socket 0 in raw mode

• implement GPIODevice for stm32 HAL
 - different kinds of GPIO should be implemented
 - digital input
 - digital output
 - analog input (ADC)
 - analog output (DAC)
 - PWM

• add a filesystem
 - make under toplevel directory called "fs"
 - should be device independent and take a single BlockDevice as input
 - consider using an already existing standard like FAT/FAT32/exFAT etc.
 - can be "write sequential / read sequential" i.e. we don't really need random access

• string library
 - put in top level directory called "string"
 - should have a fixed size (no dynamic memory please!)
 - overloading common operators is ideal
 - overloading operator= is a must (but still no dynamic memory! just truncate if the copied string is too large)
 - Aaron is working on this at the moment

• clock synchronization
 - we may need a way to synchronize the clocks on each module
 - this clock should only really be used for logging and maybe controls, i.e. don't readjust the clock the scheduler uses
 - perhaps just store an offset to the local system clock? and then calculate the "global time" with that?
 - needs to be distributed and decentralized, we can't have a single time source server
 - look into global average and local average algorithms
 - probably can't (or shouldn't) ignore the latency between modules, especially with low power NICs and custom software
 - if we ignore latency, we also make the system less modular since the speed of any given module effects the accuracy of this algorithm



Things that needed doing but are now done:

• add GPIO device abstraction
 - probably per pin, pins can be looked up by device string name
 - should just have a set and a get
 - done 9/18/22, see device/GPIODevice.h