Led

.github/workflows/build.yml

@@ -0,0 +1,21 @@
+name: Build
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Install dependencies
+        run: sudo apt-get install -qq scons gcc-avr binutils-avr avr-libc
+
+      - name: Build
+        run: scons

README.md

@@ -1,20 +1,39 @@
-# nanoBoot
+# nanoBoot (w/LED)
 
-[![Build Status](https://travis-ci.org/volium/nanoBoot.svg?branch=master)](https://travis-ci.org/volium/nanoBoot)
+## HID bootloader with LED support & overwrite protection
 
-This repository contains the source code for the USB HID-based bootloader for ATmegaXXU4 family of devices.
+<!-- CI not yet used by osamu: [![Build Status](https://travis-ci.org/volium/nanoBoot.svg?branch=master)](https://travis-ci.org/volium/nanoBoot) -->
 
-The name *nanoBoot* comes from the fact that the compiled source fits in the smallest available boot size on the ATMegaXXu4 devices, 256 words or 512 bytes. The code is based on Dean Camera's [LUFA](https://github.com/abcminiuser/lufa) USB implementation, but it is **EXTREMELY** streamlined, size-optimized and targeted for the [ATmega16U4](http://www.atmel.com/devices/atmega16u4.aspx) and [ATmega32u4](http://www.atmel.com/devices/atmega32u4.aspx) devices; I had to make quite a few hardware assumptions, mostly to the fuse settings related to clock configuration for things to be as compact as possible, but the code still allows for some flexibility.
+This repository [nanoBoot w/LED](https://github.com/osamuaoki/nanoBoot) contains the source code for the USB HID-based bootloader for ATmega32U4 family of devices with **LED support and overwrite protection**.
 
-It's very likely that a few sections can be rewritten to make it even smaller, and the ultimate goal is to support EEPROM programming as well, although that would require changes to the host code.
+The name **nanoBoot** comes from the fact that the compiled source fits in the smallest available boot size  on the ATMega32u4 devices, 256 words or **512 bytes**. The code is based on Dean Camera's [LUFA](https://github.com/abcminiuser/lufa) USB implementation, but it is **EXTREMELY** streamlined, size-optimized and targeted for the [ATmega16U4](http://www.atmel.com/devices/atmega16u4.aspx) and [ATmega32u4](http://www.atmel.com/devices/atmega32u4.aspx) devices.
 
-The current version (commit #[d0ea26b](https://github.com/volium/nanoBoot/commit/d0ea26bb01e764340dc8ad7b473ad98cefdb52eb)) is supported as-is in the 'hid_bootloader_loader.py' script that ships with [LUFA-151115](https://github.com/abcminiuser/lufa/releases/tag/LUFA-151115), and is exactly 506 bytes long.
+Initial and major portion of manual assembly code optimization efforts were performed by [volium](https://github.com/volium) and published as the original [volium/nanoBoot](https://github.com/volium/nanoBoot).
+
+Some tweaks were performed by osamu to allow arbitrary setting for CKDIV8 fuse and it was merged to the upstream.
+
+There were a lot of manual size optimization and program size check feature addition by [sigprof](https://github.com/sigprof) and published as [sigprof/nanoBoot](https://github.com/sigprof/nanoBoot)
+
+Osamu gathered all useful code and made a linear history commits with his LED support added as **led** branch here at [osamuaoki/nanoBoot](https://github.com/osamuaoki/nanoBoot).
+
+Binary size:
+* 468 bytes (proposed to upstream as default)
+    * no LED
+* 474 bytes (opt-in for upstream but default in my branch)
+    * enable LED support with "LED_ACTIVE_LEVEL  1" (Leonardo, Nano, Teensy 2.0-type)
+* 476 bytes (opt-in)
+    * enable LED support with "LED_ACTIVE_LEVEL  0" (Promicro-type)
+
+The current version (2021-12-08) will be tested manually with the compiled `hid_bootloader_cli.c` from [LUFA](https://github.com/abcminiuser/lufa) on Debian GNU/Linux 12 (bookworm/testing).
+
+Required packages on Debian GNU/Linux system: `gcc-avr`, `avr-libc`, `binutils-avr`, `libusb-dev`, `build-essential`, `git`
 
 ## HW assumptions:
 
 * CLK is 16 MHz Crystal and fuses are setup correctly to support it:
     * Select Clock Source (CKSEL3:CKSEL0) fuses are set to Extenal Crystal, CKSEL=1111 SUT=11
-    * Divide clock by 8 fuse (CKDIV8) can be set to either 0 or 1
+    * Divide clock by 8 fuse (CKDIV8) can be any value.
+    * 16 MHz operation needs 5V VCC for MCU
 * Bootloader starts on reset; Hardware Boot Enable fuse is configured, HWBE=0
 * Boot Flash Size is set correctly to 256 words (512 bytes), StartAddress=0x3F00, BOOTSZ=11
 * Device signature = 0x1E9587
@@ -24,10 +43,64 @@ The current version (commit #[d0ea26b](https://github.com/volium/nanoBoot/commit
     * hfuse memory = 0xD6 (EESAVE=0, BOOTRST=0)
     * efuse memory = 0xC7 (=0xF7, No BOD)
 
-* Alternatively, BOD can be used to ease CKSEL-SUT setting requirements to
-  allow teensy-like FUSE settings:
+* Alternatively BOD can be used to ease CKSEL-SUT setting requirements to
+  allow teensy like FUSE setting
     * lfuse memory = 0x5F (CKDIV8=0, 16CK + 0ms)
     * hfuse memory = 0xDF (EESAVE=1, BOOTRST=1)
-    * efuse memory = 0xF4 (BOD=2.4V)
+    * efuse memory = 0xC4 (=0xF4, BOD=2.4V)
+
+* LED on D6 port for Teensy 2.0 (Configurable in #define for any board)
+
+## Usage
+
+Please install this bootloader `nanoBoot.hex` using the ISP connected programmer (e.g. AVRISP mkII).
+
+```
+$ sudo avrdude -v -p atmega32u4 -c avrisp2 -Pusb -e -U flash:w:nanoBoot.hex \
+             -U lfuse:w:0x5f:m -U hfuse:w:0xdf:m -U efuse:w:0xc4:m
+```
+
+You can start this bootloader by connecting the board to the PC with USB cable and pressing the RESET button.  It is good idea to monitor the PC's USB connection.
+
+```
+ $ watch lsusb
+```
+
+If this bootloader is started, you should see "Atmel".
+
+Please note, now this bootloader turns on LED just before sending device ID.  Thus monitoring of USB is now optional.
+
+(If LED doesn't turn on even after 10 second wait for any reason, press the RESET button again.)
+
+Then program MCU with, e.g., a `LED.hex` firmware as:
+
+```
+ $ sudo hid_bootloader_cli -mmcu=atmega32u4 -v LED.hex
+```
+Please note, this bootloader turns off LED upon finish programming.
+
+(Pressing the RESET button during active bootloader execution seems to halt the bootloader.  This seems to be the reason you need to press the RESET button again.)
+
+For your convenience, pre-compiled HEX file and associated scripts are provided under the `precompile` directory.
+
+## Configuration
+
+Only the first configuration choice is tested with a Teensy 2.0 compatible board.
+
+In `Makefile`:
+
+* `F_CPU = 16000000` or `F_CPU = 8000000`
+* `BOOT_START_OFFSET = 0x7E00` or any valid ones for MCU
+
+In `nanoBoot.S`:
+
+* Adjust `#define LED_BIT`, `#define LED_CONF`, and `#define LED_PORT` , and `#define LED_ACTIVE_LEVEL` for each board.  Default is Teensy 2.0 setting.
+
+## Documentation
+
+"The documentation is part of the source code itself, and even though some people may find it extremely verbose, I think that's better than lack of documentation; after all, assembly can be hard to read sometimes... ohhh yes, in case that was not expected, this is all written in pure GAS (GNU Assembly), compiled using the [Atmel AVR 8-bit Toolchain](http://www.atmel.com/tools/atmelavrtoolchainforwindows.aspx)." (per volium)
+
+"The elegant programming techniques presented by volium with detailed comments were very enlightening for me to get started. It's delightful for me to read.  Don't miss it!"  (per osamu)
 
-The documentation is part of the source code itself, and even though some people may find it extremely verbose, I think that's better than lack of documentation; after all, assembly can be hard to read sometimes... ohhh yes, in case that was not expected, this is all written in pure GAS (GNU Assembly), compiled using the [Atmel AVR 8-bit Toolchain](http://www.atmel.com/tools/atmelavrtoolchainforwindows.aspx).
+ * [AVR Instruction Set Manual](http://ww1.microchip.com/downloads/en/devicedoc/atmel-0856-avr-instruction-set-manual.pdf)
+ * [ATmega16U4, ATmega32U4 - Complete Datasheet](http://ww1.microchip.com/downloads/en/devicedoc/atmel-7766-8-bit-avr-atmega16u4-32u4_datasheet.pdf)