Firmware verification working branch

[dkerr64]

I merged in the master branch from https://github.com/cfurter/Arduino-HomeKit-ESP8266

The changes to ardunio_homekit_server.cpp are largely cosmetic... fixes to spelling errors, but there is one likely significant... a change from boolean && to a bitwise & operator in an if statement... if (!(ch->permissions & homekit_permissions_notify))

The changes to storage.c are considerable.  You can see the commit history here... https://github.com/cfurter/Arduino-HomeKit-ESP8266/commits/master/ only the last 6 are by cfurter, he forked from another fork which I had earlier merged in.  I think I made a mistake forking from the original https://github.com/Mixiaoxiao/Arduino-HomeKit-ESP8266... I should probably have started out by forking from one of the other forks as I now have a rather messy commit history that essentially tried to get my branch in sync with changes others had made.

My other "non-development" ratgdo crashed with the same error, and I used the esptool verify_flash command to confirm the same overwriting.  I have now installed the version that is on github onto both my devices.  I did have to reset/re-pair both to HomeKit as the pairing was lost.  That is unfortunate but unless you can decipher all cfurter's changes to storage.c and figure out why, I think we may have to live with this.

This version also has the checkFlashCRC() call on every request for status.  So you will notice a slowdown in page refresh.  Hopefully we can remove this once we have confidence that we have really found the bug.

[dkerr64]

Documenting history....

I added a checkFlashCRC call every time the browser checks for status. This morning I opened up the browser and saw the message that checkFlashCRC failed, after only 13 hours. So...

$ python3 -m esptool -b 921600 -p /dev/ttyUSB1 verify_flash --diff yes 0x0000 ~/firmware-0531-10pm.bin
esptool.py v4.7.0
Serial port /dev/ttyUSB1
Connecting....
Detecting chip type... Unsupported detection protocol, switching and trying again...
Connecting....
Detecting chip type... ESP8266
Chip is ESP8266EX
Features: WiFi
Crystal is 26MHz
MAC: 08:3a:8d:f9:ef:36
Uploading stub...
Running stub...
Stub running...
Changing baud rate to 921600
Changed.
Configuring flash size...
Verifying 0x91e40 (597568) bytes @ 0x00000000 in flash against /home/david/firmware-0531-10pm.bin...
-- verify FAILED: 1164 differences, first @ 0x00000080
   00000080 00 7c
   00000081 00 12
   00000083 00 60
   00000084 00 88
   00000085 00 dc
   00000087 00 40
   00000088 00 cd
   00000089 00 20

And then we found in homekit storage.c I find this code...

int homekit_storage_reset_pairing_data() {

    byte blank[sizeof(pairing_data_t) * MAX_PAIRINGS];
    bzero(blank,sizeof(blank));

    INFO("Formatting HomeKit storage at 0x%x", PAIRINGS_OFFSET);
    if (!spiflash_write(PAIRINGS_OFFSET, blank, sizeof(blank))) {
        ERROR("Failed to erase HomeKit pairing storage");
        return -1; // Fail case
    }
    return 0;
}

The value of PAIRINGS_OFFSET is 128 (0x80) The sizeof(blank) is 1280 (0x500)

Thus... we discovered that our HomeKit branch should probably sync up with that found here.