Flash an "autobox" wireless carplay adapter with custom firmware

flash.py

# Notes, file size seems to cap around 4 mb, if you go over, the flash fails and you have to do a SPI flash (or find a way in the uart console)
import base64
import json
import math
import requests
import time
import os



file = 'custom.tar'
presult = 1
pversion = 375
pitemsize = 32768

file = open(file, 'br')

# get the file size
file.seek(0, os.SEEK_END)
pfilesize = file.tell()
file_inc_down = pfilesize
print("Size of file is:", pfilesize, "bytes")
print('DL', end='')
file.seek(0)

# Get page count
pcount = math.ceil(pfilesize / pitemsize)
requests.post('http://192.168.2.1/getupdatestatus')
# Run through all pages
ppos = 0
while ppos < pcount:
    payload = {
        'result': presult,
        'version': pversion,
        'pos': ppos,
        'itemsize': pitemsize,
        'count': pcount,
        'filesize': pfilesize
    }
    if file_inc_down < pitemsize:
        # Set metadata
        payload['datasize'] = file_inc_down
        # Read in data
        data = file.read(file_inc_down)
    else:
        # Set metadata
        file_inc_down -= pitemsize
        payload['datasize'] = pitemsize
        # Read in data
        data = file.read(pitemsize)

    payload['data'] = base64.b64encode(data).decode('ascii')

    # Upload file
    r = requests.post('http://192.168.2.1/uploadappdatas', headers={'X-Requested-With': 'XMLHttpRequest', 'Accept': 'application/json, text/javascript, */*; q=0.01', 'Content-Type': 'application/x-www-form-urlencoded; charset=UTF-8'}, data=json.dumps(payload, separators=(',', ':')))
    dat = r.json()
    if dat['result'] == 0:
        print('Err?')
        print(dat)
        print(payload)
        time.sleep(1)
    else:
        print('.', end='')
    ppos += 1

# Perform the install
print('\ninstalling... ', end='')
start = requests.post('http://192.168.2.1/requestupdate').json()
if start['result']  == 0:
        print('Err?')
        print(start)
        exit(1)

inst = 0
while inst < 100:
    prog = requests.post('http://192.168.2.1/getupdatestatus').json()
    inst = prog['percent']
    print(" ", inst, end=' ')
    time.sleep(1)