WDT reset does not load bootloader, only external reset does

[ASL07]

Hello,

I am trying to reset my device using the watchdog to enter the bootloader, the device resets, however, after the reset, the appication code is loaded, instead of the bootloader.
As per Atmel datasheet, if BOOTRST is programmed, then the code loaded after both WDT reset and external reset should be the bootloader.

When I set the reset pin to low instead of doing a WDT reset, then the bootloader is loaded before the application.

I have loaded the bootloader properly and the BOOTRST fuse is programmed, see the output below

avrdude: Version 6.3-20171130
         Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
         Copyright (c) 2007-2014 Joerg Wunsch

         System wide configuration file is "/Applications/Arduino.app/Contents/Java/hardware/tools/avr/etc/avrdude.conf"
         User configuration file is "/Users/developer/.avrduderc"
         User configuration file does not exist or is not a regular file, skipping

         Using Port                    : usb
         Using Programmer              : stk500v2
avrdude: usbdev_open(): Found AVRISP mkII, serno: 111010262908
         AVR Part                      : ATmega2560
         Chip Erase delay              : 9000 us
         PAGEL                         : PD7
         BS2                           : PA0
         RESET disposition             : dedicated
         RETRY pulse                   : SCK
         serial program mode           : yes
         parallel program mode         : yes
         Timeout                       : 200
         StabDelay                     : 100
         CmdexeDelay                   : 25
         SyncLoops                     : 32
         ByteDelay                     : 0
         PollIndex                     : 3
         PollValue                     : 0x53
         Memory Detail                 :

                                  Block Poll               Page                       Polled
           Memory Type Mode Delay Size  Indx Paged  Size   Size #Pages MinW  MaxW   ReadBack
           ----------- ---- ----- ----- ---- ------ ------ ---- ------ ----- ----- ---------
           eeprom        65    10     8    0 no       4096    8      0  9000  9000 0x00 0x00
           flash         65    10   256    0 yes    262144  256   1024  4500  4500 0x00 0x00
           lfuse          0     0     0    0 no          1    0      0  9000  9000 0x00 0x00
           hfuse          0     0     0    0 no          1    0      0  9000  9000 0x00 0x00
           efuse          0     0     0    0 no          1    0      0  9000  9000 0x00 0x00
           lock           0     0     0    0 no          1    0      0  9000  9000 0x00 0x00
           calibration    0     0     0    0 no          1    0      0     0     0 0x00 0x00
           signature      0     0     0    0 no          3    0      0     0     0 0x00 0x00

         Programmer Type : STK500V2
         Description     : Atmel STK500 Version 2.x firmware
         Programmer Model: AVRISP mkII
         Hardware Version: 0
         Firmware Version Master : 1.41
         Vtarget         : 3.3 V
         SCK period      : 8.00 us

avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.00s

avrdude: Device signature = 0x1e9801 (probably m2560)
avrdude: safemode: lfuse reads as FF
avrdude: safemode: hfuse reads as D8
avrdude: safemode: efuse reads as FD
avrdude: NOTE: "flash" memory has been specified, an erase cycle will be performed
         To disable this feature, specify the -D option.
avrdude: erasing chip
avrdude: reading input file "iplace_controller_boot.hex"
avrdude: writing flash (257926 bytes):

Writing | ################################################## | 100% 0.00s

avrdude: 257926 bytes of flash written
avrdude: verifying flash memory against iplace_controller_boot.hex:
avrdude: load data flash data from input file iplace_controller_boot.hex:
avrdude: input file iplace_controller_boot.hex contains 257926 bytes
avrdude: reading on-chip flash data:

Reading | ################################################## | 100% 0.00s

avrdude: verifying ...
avrdude: 257926 bytes of flash verified
avrdude: reading input file "0x0F"
avrdude: writing lock (1 bytes):

Writing | ################################################## | 100% 0.01s

avrdude: 1 bytes of lock written
avrdude: verifying lock memory against 0x0F:
avrdude: load data lock data from input file 0x0F:
avrdude: input file 0x0F contains 1 bytes
avrdude: reading on-chip lock data:

Reading | ################################################## | 100% 0.00s

avrdude: verifying ...
avrdude: 1 bytes of lock verified

avrdude: safemode: lfuse reads as FF
avrdude: safemode: hfuse reads as D8
avrdude: safemode: efuse reads as FD
avrdude: safemode: Fuses OK (E:FD, H:D8, L:FF)

avrdude done.  Thank you.

And this is the code I am using to trigger a WDT reset:

NetEEPROM.writeImgBad();
wdt_disable();
wdt_enable(WDTO_120MS);
while(1);

Thanks for your help

[ASL07]

I found the solution.
Just comment out this line in main.c

if (!(ch & _BV(EXTRF))) appStart(); //if not external (hard reset) skip bootloader