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documentation/developer_environment.md

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+# build
+
+two environments:
+
+## atomcam tools (first)
+
+`git clone https://github.com/mnakada/atomcam_tools`
+
+`cd atomcam_tools`
+
+`make`
+
+then wait a long time for the development environment to compile and complete.
+
+After its complete, run `docker-compose up -d` to start the docker instance.  
+
+To resume the instance, get the container ID from `docker ps`, and use `docker exec -it <container_Id> /bin/bash`
+
+the following is translated from: [https://github.com/mnakada/atomcam_tools/blob/71a1214f83a92704221cedcf5101e12ba40f2f38/build.md?plain=1#L200](https://github.com/mnakada/atomcam_tools/blob/71a1214f83a92704221cedcf5101e12ba40f2f38/build.md?plain=1#L200)
+
+
+
+###  Docker environment
+In the Docker environment, / src is mapped to atomcam_tools /.
+
+Below, basically the commands in Docker are executed from the following Directory.
+
+```
+root@ac0375635c01: / atomtools # cd / atomtools / build / buildroot -2016.02
+```
+
+rootfs uses gcc in Docker in a glibc environment.
+Gcc is also generated during build.
+gcc prefix is
+** / atomtools / build / buildroot-2016.02 / output / host / usr / bin / mipsel-ingenic-linux-gnu-**
+is.
+
+ATOM Cam's original system camera app iCamera_app is built in the uClibc environment.
+
+Therefore, uClibc environment is required to build libcallback.so for hack of iCamera_app, so it is cloned separately.
+** / atomtools / build / mips-gcc472-glibc216-64bit / bin / mips-linux-uclibc-gnu-**
+using.
+
+
+
+###  How to build when making various changes
+
+When changing the config of initramfs and kernel
+
+```
+root @ ac0375635c01: / atomtools # make linux-rebuild
+root@ac0375635c01: / atomtools # cp output / images / uImage.lzma /src
+```
+
+Will be built with and copied to atomcam_tools /.
+
+---
+
+
+If you modify the files in rootfs or the menuconfig of busybox
+```
+root@ac0375635c01: / atomtools # make
+root@ac0375635c01: / atomtools # cp output / images / rootfs.ext2 /src
+```
+
+Will be built with and copied to atomcam_tools /.
+
+
+Copy it to the SD Card with the names factory_t31_ZMC6tiIDQN and rootfs_hack.ext2 respectively.
+
+---
+
+If you change the package included in rootfs
+
+```
+root @ ac0375635c01: / atomtools # make menuconfig
+root @ ac0375635c01: / atomtools # make
+```
+
+Will build rootfs.
+
+---
+
+For individual package rebuilds
+
+```
+root @ ac0375635c01: / atomtools # make < package > -rebuild
+```
+
+---
+
+When changing settings such as busybox commands
+
+```
+root @ ac0375635c01: / atomtools # make busybox-menuconfig
+root @ ac0375635c01: / atomtools # make
+```
+
+Will build rootfs.
+
+
+---
+
+When changing kernel settings
+
+```
+root @ ac0375635c01: / atomtools # make linux-menuconfig
+root @ ac0375635c01: / atomtools # make linux-rebuild
+```
+
+Will generate uImage.lzma.
+
+----
+
+## buildroot (second)
+
+download `https://buildroot.org/downloads/buildroot-2022.05.tar.xz`
+
+run `make menuconfig`
+
+options should be:
+
+- Target Options:
+   - Target Architecture
+     - MIPS (little endian)
+   - Target Architecture Variant
+     - Generic MIPS32R2
+   - FP Mode
+     - 32
+
+- Build Options:
+  - Strip Target Binaries [*]
+  - Libraries
+    - static only ( you can do dynamic if you like, just remember you have to copy ALL the program's required libararies to the device! )
+
+
+
+- Toolchain
+  - C library:
+    - musl (you can also use uClibc-ng if you prefer)
+    - Kernel Headers
+      - Manually Specified Linux Version
+        - 3.10.98
+    - Custom Kernel Headers Series
+        - 3.10.x
+     - Binutils Version
+        - 2.36.1
+     - GCC Compiler Version
+        - gcc 9.x
+     - Enable C++ Support [*]
+     - Enable compiler link-time-optimization support [*]
+   
+ - Target packages
+   - Whatever packages you want!
+
+Then select exit, save changes, and then run `make` and your compiled programs should be in `output/target/usr/`
+
+