Could you ask for inclusion of this bootloader in official Boards Manager?

[q2dg]

This would give a lot more of visibility to your fantastic project and, moreover, it should make installation of avr_boot a lot easier...as only selecting the target "board" in the menu, the menu option "Burn bootloader" should do the rest.

See: https://github.com/arduino/Arduino/wiki/Arduino-IDE-1.5-3rd-party-Hardware-specification

Thanks

[zevero]

Very good idea! I would love to see this.

Are you willing to do it?
Do you have some background on how this is done?
Unfortunately the Boot Loader part seems not to be documented in your link and I would need to invest some time ...

[q2dg]

Oooh, sorry, I haven't such technical skills. But I know this other project https://github.com/NicoHood/HoodLoader2 which has achieved this (it's a custom bootloader designed to be loaded in UNO's Atmega16U2 to convert it into a Leonardo-like board). Its author is @NicoHood
Thanks a lot

[NicoHood]

An example can be found here:
https://github.com/NicoHood/HoodLoader2

@per1234 helped me with the packaging of the files:
NicoHood/HoodLoader2#21

You can ask him for help too i guess.

[per1234]

Unfortunately the Boot Loader part seems not to be documented in your link and I would need to invest some time ...

Actually this is the specification for adding Boards Manager support: https://github.com/arduino/Arduino/wiki/Arduino-IDE-1.6.x-package_index.json-format-specification

This may also provide some useful information on potential locations for the necessary files: http://playground.arduino.cc/Main/BoardsManagerSupport

I have helped add Boards Manager installation support to 8 projects now and am willing to provide assistance for this one also. The bootloader files and boards.txt for all boards that you want to support will need to be made and tested before doing the Boards Manager work.

[zevero]

Oh hi @per1234 you helped me here maniacbug/mighty-1284p#14

I don't really understand the process of adding boards. Adding a board would more be like for example adding 1284p support like in
https://github.com/JChristensen/mighty-1284p/tree/v1.6.3
(which would be nice).

Ok, now for Bootloaders I assume we need a seperate Board for every Bootloader? Or can we have multiple Bootloaders for a given board?

I have only limited knowledge of Arduino packaging ... if you coulld tell me what exactly you need, it would be easier for me.

I guess we will need a hex file for every board.
I assume we will not have any options, so we will compile without LED or UART, therefore we dont need to configure anything really (FAT12, FAT16 and FAT32 - support ist default).
We therefore only need to set

• MCU_TARGET: Your AtmegaXXX
• BOOT_ADR: in bytes not words!
• F_CPU: CPU Frequency

+FUSES

Keep in mind that we need 4k and after the bootloader is installed flashing via Serial does not work anymore. (We still have 500 bytes left so serial support should be quite feasible however...)

[per1234]

I don't really understand the process of adding boards. Adding a board would more be like for example adding 1284p support like in

It's just adding a new entry to the Tools > Board menu in the Arduino IDE. That could mean adding support for a new MCU as the Mighty 1284P project did. A different configuration of hardware already supported by the Arduino IDE. Or a different bootloader such as your project. I have even used it to add a new programmer to the Tools > Programmers menu. Boards Manager makes it easy for people to install hardware files to the Arduino IDE and keep them updated simply by adding a URL to File > Preferences > Additional Boards Manager URLs. Arduino IDE 1.6.6 has added a notification when a new version of any package installed with Boards Manager is available so the users will be able to immediately update with just a click.

Ok, now for Bootloaders I assume we need a seperate Board for every Bootloader? Or can we have multiple Bootloaders for a given board?

You can have multiple bootloader for each board but there are some limitations. Each selection in the Tools > Board menu can have other custom menus. So for example the Board entry could be ATmega328P and then there could be a custom menu for USE_LED: Yes, No. Then the selection will determine which bootloader is used. Unfortunately we can't also have a menu for USE_UART: Yes, No so you would either need an "ATmega328P" and an "ATmega328P Debug" Board menu entry or the custom menu could be Configuration: USE_LED + USE_UART, USE_LED, USE_UART, no LED + no UART. There can be a separate menu for clock speeds and if you do the trick with using the 16MHz bootloader for the 8MHz board but setting the baud rate to half then those can all be on a single Board menu entry. You can see an example of this in the alternative boards.txt file I wrote for the Mighty 1284P project: https://github.com/JChristensen/mighty-1284p/blob/v1.6.3/avr/boards.txt.alt It offers the choice of 20MHz, 16MHz Low Power, 16MHZ Full Swing, and 8MHz internal clock

So at a minimum we need a 16MHz bootloader file for each MCU that will be supported. If you want to have LED and UART options then there would need to be 4 bootloader files for each MCU to support all possible combinations of the 2 options. If you want to offer 20MHz clock option then that would require another bootloader(or 4) for each MCU. I'm willing to make the bootloaders but I may not be able to test all options so I might need help there.

Other than that you will need to decide:

• Location for the JSON file(this will be the URL that is added to Preferences to install avr_boot) - I'm partial to creating a gh-pages branch for it because that makes the URL short and keeps the file separate from the rest of the project.
• Location for the installation archive file. It makes sense to put this in the same location as the JSON file but that may require the installation archive file to be manually created for each release. Another option is to create a boards manager branch of the repo and then when you create release from that branch GitHub will automatically create the installation archive file. An example of this is https://github.com/SpenceKonde/ATTinyCore/tree/boardmanager. In that case you would create a standard release and a Boards Manager release for each version and clearly state the difference.
• Name of the JSON file. There is a specification:

package_YOURNAME_PACKAGENAME_index.json
The prefix package_ and the postfix _index.json are mandatory (otherwise the index file is not recognised by the IDE) while the choice of YOURNAME_PACKAGENAME is left to packager. We suggest to use a domain name owned by the packager for example:

So let me know if you have any questions. Once you have made the decision of how you want this implemented I'm happy to take over and submit pull requests or just provide assistance. I'm also willing to be in charge of adding new versions to the JSON file as they are released. Just let me know what you want me to do.

[zevero]

I think it is too complicated to provide options for LED (needs configuration of two pins) and UART (needs the divider for the baud rate).
For the latter it would be nice if I could autodetect the baud rate (and also have a serial bootloader as well). But for the time beeing I would not include any options as they are not really needed. (if someone needs to debug, he will be able to compile himself)

I pretty much would like to let you decide on all the other details. Avr_boot is not really "my work". I only adapted existing ideas to get my project up and running. I dont need credits and am happy already, if others can save some time.

So please fork and I am happy to pull all your requests. If you wish branches we can have branches.
Or you start your own rep from scratch. I really dont mind. The easier the better. Life is already complicated enough ;)

So just go ahead and use everything. If you want my help, tell me, what I should do.
I hope I can someday merge a serial bootloader in. So tell me how I would do that, after your work...
If I can see how everything works I could do it myself in the future, but for now it is better you take over.

[per1234]

I'd like to add support for:

• ATmega168
• ATmega328P
• ATmega32u4
• ATmega1284P
• ATmega2560

And clock options:

• 8MHz internal
• 16MHz Low Power
• 16MHz Full Swing
• 20 MHz Full Swing

Do you think the avr_boot will work for all of those without modification?

It sounds like you would like this functionality to be as low-maintenance as possible on your part so I think I will just put all the Boards Manager files in the gh-pages branch. That way you will only need to accept one pull request for each release.. So go ahead and create the gh-pages branch when you get a chance as I can't do that via pull request.

[zevero]

I know of no reason why it shouldn work.

Perfekt. gh-pages branch is set up!

[per1234]

I'm going to add instructions for installation and use with the Arduino IDE. Do you want me to add these to the README.md in the master branch or should I put it in the gh-pages branch?

[zevero]

What do you think about having the instructions on the gh-pages branch and I will add a prominent Link in top of my README.md ?
This would make it clear to the user that he can choose between compiling and flashing himself or installing via Arduino IDEs Board Manager.

[per1234]

I'm making the bootloader files and I ran into a couple of snags. The first is that the bootloader sizes are larger for me than you state in the documentation. Here's the avr-size output:

   text    data     bss     dec     hex filename
      0    4080       0    4080     ff0 atmega1284p_16mhz.hex
      0    4080       0    4080     ff0 atmega1284p_20mhz.hex
      0    4080       0    4080     ff0 atmega1284p_8mhz.hex
      0    4040       0    4040     fc8 atmega328p_16mhz.hex
      0    4040       0    4040     fc8 atmega328p_20mhz.hex
      0    4040       0    4040     fc8 atmega328p_8mhz.hex
      0    4108       0    4108    100c atmega32u4_16mhz.hex
      0    4108       0    4108    100c atmega32u4_20mhz.hex
      0    4108       0    4108    100c atmega32u4_8mhz.hex

So ATmega1284P and ATmega328P are still fine but the ATmega32U4 is too big to fit in the max section of 4096 bytes. I'm using make.exe from WinAVR-20100110 which is the most recent version I have found and everything else from the Arduino 1.6.6 installation. This is with USE_LED = 0 and USE_UART = 0. My makefile is here: https://github.com/per1234/avr_boot/blob/dev/Makefile I had to add some stuff to make it work with the Windows paths. So worst case scenario I just won't add ATmega32U4 but it's strange to me that the size is so different.

The second issue I'm running into is when I try to make the ATmega2560 bootloader files I get some errors:

rm -rf *.o avr_boot.elf *.eps *.bak *.a *.bin
rm -rf *.lst *.map
rm -rf avr_boot.hex
../../../../tools/avr/bin/avr-gcc -gdwarf-2 -Wall -Os -mcall-prologues -ffunction-sections -fdata-sections -mmcu=atmega2560 -std=c99 -DBOOT_ADR=0x3F000 -DF_CPU=16000000 -DUSE_LED=0 -DUSE_UART=0   -c -o main.o main.c
../../../../tools/avr/bin/avr-gcc -gdwarf-2 -Wall -Os -mcall-prologues -ffunction-sections -fdata-sections -mmcu=atmega2560 -std=c99 -DBOOT_ADR=0x3F000 -DF_CPU=16000000 -DUSE_LED=0 -DUSE_UART=0   -c -o diskio.o diskio.c
../../../../tools/avr/bin/avr-gcc -c -mmcu=atmega2560 -I. -x assembler-with-cpp-Wa,-adhlns=asmfunc.lst,-gstabs -DBOOT_ADR=0x3F000 -DF_CPU=16000000 -DUSE_LED=0-DUSE_UART=0 asmfunc.S -o asmfunc.o
../../../../tools/avr/bin/avr-gcc -gdwarf-2 -Wall -Os -mcall-prologues -ffunction-sections -fdata-sections -mmcu=atmega2560 -std=c99 -DBOOT_ADR=0x3F000 -DF_CPU=16000000 -DUSE_LED=0 -DUSE_UART=0 -Wl,-Map,avr_boot.map -Wl,--gc-sections -Wl,--section-start,.text=0x3F000 -o avr_boot.elf main.o pff/src/pff.o diskio.o uart/uart.o asmfunc.o
c:/program files (x86)/arduino-nightly/hardware/tools/avr/bin/../lib/gcc/avr/4.8.1/../../../../avr/bin/ld.exe: avr:51 architecture of input file `pff/src/pff.o' is incompatible with avr:6 output
c:/program files (x86)/arduino-nightly/hardware/tools/avr/bin/../lib/gcc/avr/4.8.1/../../../../avr/bin/ld.exe: avr:51 architecture of input file `uart/uart.o' is incompatible with avr:6 output
collect2.exe: error: ld returned 1 exit status
make: *** [avr_boot.elf] Error 1

Any ideas?

[NicoHood]

WinAVR is just OLD. Use a recent avr-gcc and the size will be probably a lot smaller.
With avr-gcc 5.1 and LTO you can get tons of bytes back.
https://github.com/NicoHood/HoodLoader2/wiki/Developer-Information

Edit: just downloaded the default master package and hit make without modifications. Got the following error:

avr_boot-master$ make
rm -rf *.o avr_boot.elf *.eps *.bak *.a *.bin
rm -rf *.lst *.map 
rm -rf avr_boot.hex
avr-gcc -gdwarf-2 -Wall -Os -mcall-prologues -ffunction-sections -fdata-sections -mmcu=atmega1284p  -std=c99 -DBOOT_ADR=0x1F000  -DF_CPU=16000000    -DUSE_LED=0         -DUSE_UART=1          -c -o main.o main.c
avr-gcc -gdwarf-2 -Wall -Os -mcall-prologues -ffunction-sections -fdata-sections -mmcu=atmega1284p  -std=c99 -DBOOT_ADR=0x1F000  -DF_CPU=16000000    -DUSE_LED=0         -DUSE_UART=1          -c -o pff/src/pff.o pff/src/pff.c
pff/src/pff.c: In function ‘get_fat’:
pff/src/pff.c:372:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
   wc = LD_WORD(buf);
   ^
pff/src/pff.c:379:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
   return LD_WORD(buf);
   ^
pff/src/pff.c:384:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
   return LD_DWORD(buf) & 0x0FFFFFFF;
   ^
pff/src/pff.c: In function ‘pf_mount’:
pff/src/pff.c:775:5: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
     bsect = LD_DWORD(&buf[8]); /* Partition offset in LBA */
     ^
avr-gcc -gdwarf-2 -Wall -Os -mcall-prologues -ffunction-sections -fdata-sections -mmcu=atmega1284p  -std=c99 -DBOOT_ADR=0x1F000  -DF_CPU=16000000    -DUSE_LED=0         -DUSE_UART=1          -c -o diskio.o diskio.c
avr-gcc -gdwarf-2 -Wall -Os -mcall-prologues -ffunction-sections -fdata-sections -mmcu=atmega1284p  -std=c99 -DBOOT_ADR=0x1F000  -DF_CPU=16000000    -DUSE_LED=0         -DUSE_UART=1          -c -o uart/uart.o uart/uart.c
avr-gcc -c -mmcu=atmega1284p  -I. -x assembler-with-cpp -Wa,-adhlns=asmfunc.lst,-gstabs -DBOOT_ADR=0x1F000   -DF_CPU=16000000    -DUSE_LED=0         -DUSE_UART=1        asmfunc.S -o asmfunc.o
avr-gcc -gdwarf-2 -Wall -Os -mcall-prologues -ffunction-sections -fdata-sections -mmcu=atmega1284p  -std=c99 -DBOOT_ADR=0x1F000  -DF_CPU=16000000    -DUSE_LED=0         -DUSE_UART=1        -Wl,-Map,avr_boot.map -Wl,--gc-sections -Wl,--section-start,.text=0x1F000   -o avr_boot.elf main.o pff/src/pff.o diskio.o uart/uart.o asmfunc.o 
/usr/lib/gcc/avr/4.8.2/../../../avr/bin/ld: address 0x20062 of avr_boot.elf section `.text' is not within region `text'
/usr/lib/gcc/avr/4.8.2/../../../avr/bin/ld: address 0x20062 of avr_boot.elf section `.text' is not within region `text'
collect2: error: ld returned 1 exit status
make: *** [avr_boot.elf] Error 1

[per1234]

@NicoHood I'm only using make.exe from WinAVR. I installed avr-gcc 5.1.0 from that link and the sizes are the same as before and the same error on the ATmega2560 compile. I also tried using the make.exe from Arduino IDE 1.0.6 which I believe is the last one that came with that file and I get the same results on both issues.