save() reports -4 bytes available on nRF51

[ddm]

Tested with the following nRF51 variants (QFN48):

• nRF51422-QFAC (256k Flash & 32k RAM) using a PCA10028 DK (NRF51822DK=1)
• nRF51822-QFAA (256k Flash & 16k RAM) using a custom board:

info = {
 'name' : "noho-plug",
 'link' :  [ "https://www.noho.care" ],
 'default_console' : "EV_SERIAL1",
 'default_console_tx' : "D29",
 'default_console_rx' : "D30",
 'default_console_baudrate' : "115200",
 'variables' : 310,
 'binary_name' : 'noho-plug.bin',
 'build' : {
  'defines' : [
     'USE_BLUETOOTH'
   ]
 }
};

chip = {
  'part' : "NRF51822", # QFAA
  'family' : "NRF51",
  'package' : "QFN48",
  'ram' : 16,
  'flash' : 256,
  'speed' : 16,
  'usart' : 1,
  'spi' : 1,
  'i2c' : 0,
  'adc' : 1,
  'dac' : 0,
  'saved_code' : {
    'address' : ((256 - 3) * 1024),
    'page_size' : 1024,
    'pages' : 0,
    'flash_available' : (256 - 108 - 3)
  }
};

To reproduce using the PCA10028 development kit:

1. git clone https://github.com/espruino/Espruino.git && cd Espruino
2. git co 1317aa0
3. NRF51822DK=1 RELEASE=1 make
4. Flash espruino_1v86.1614_nrf51822.hex to PCA10028 DK
5. UART @ 9600 bauds/8 bits/no parity or nRF UART 2.0 (Android)
6. save() ⇒ ERROR: Too big to save to flash (xxx vs -4 bytes) regardless of the code.

[universal]

I think i had a similar issue playing with a waveshare clone, and still have other issues. I think i fixed the byte issue with a changed config, might have just been pages in the chip section which i changed. I hope i don't forget it tomorrow, i only have the code at my work machine since it is still toying around :-)

[ddm]

Funny you mention that: I noticed it works on my custom board (but not the PCA10028) when I just add the -g3 compiler flag and drop RELEASE=1. No amount of work on the saved_code board config values seems to do any good though.

[gfwilliams]

On micro:bit this works I think. Change pages:0 to pages:3 in your file - seems to be a bug in the nRF51DK board file

[ddm]

@gfwilliams Thank you for the fix Gordon! I just realised that changing gcc flags had nothing to do with me getting it to work: I had set pages:3 on my custom board too... I guess the nRFTag board should be updated since it uses the same nRF51822-QFAA variant as the micro:bit and my custom board.