Update README

README.md

@@ -1,35 +1,104 @@
 # mimic-cross
 
-A cross compile environment Docker image, can be used like docker multiarch
-image without speed penalty.
+Fast cross-compiled environment requiring no special recipes.
 
-## Usage
+## Quick start
 
-Change base image. [Example](/example/binutils.dockerfile)
+### Usage
+
+Just use this as base image and build image with `--platform` option.
+
+```Dockerfile
+FROM --platform=${BUILDPLATFORM} impactaky/mc-ubuntu22.04-${TARGETARCH}:2.0.0
+```
+
+### Run example
+
+Use [binutils build example](/example/binutils.dockerfile).
+
+```bash
+cd ./example
+docker buildx build --platform=linux/arm64,linux/amd64 -f binutils.dockerfile .
+```
+
+This is the result on my local machine. | Base image | sec | |
+------------------------------ | ----- | | ubuntu:22.04 (native compile) | 29.9
+| | ubuntu:22.04 (cross compile) | 434.8 | | mc-ubuntu22.04 (cross compile) |
+34.6 |
+
+### How to introduce mimic-cross to existing image
+
+Please write as following.
 
 ```Dockerfile
-# FROM ubuntu:20.04
-# FROM multiarch/ubuntu-core:arm64-focal
-FROM impactaky/mimic-cross:arm64-focal
+FROM --platform=${BUILDPLATFORM} impactaky/mc-ubuntu22.04-${TARGETARCH}-host:2.0.0 AS mimic-host
+FROM ubuntu:22.04
+COPY --from=mimic-host / /mimic-cross
+RUN /mimic-cross/mimic-cross.deno/setup.sh
 ```
 
+## Notes
+
+mimic-cross currently does not support the apt command, please use apt-get.
+
+mimic-cross currently does not support the pip command. Please use
+`python3 -m pip` instead.
+
 ## Supported environments
 
-Currently, support only ubuntu18.04 or 20.04 and aarch64.
+- OS
+  - ubuntu:22.04
+- Build platform
+  - linux/amd64
+  - linux/arm64
+- Target platform
+  - linux/amd64
+  - linux/arm64
+- Package manager
+  - apt-get
+- Compiler
+  - gcc-11
+  - g++-11
+- Language
+  - python3.10
+
+Supported packages can be found in
+[supported.json](/mimic-cross.deno/apt/packages/supported.json)
+
+## How to add support packages
+
+T.B.D.
+
+## How to make runable users binary
+
+T.B.D.
 
 ## How mimic-cross works
 
 ![Untitled Diagram (1)](https://user-images.githubusercontent.com/37619203/131243313-c4f6264f-621c-47b6-981b-a76f4ec7902f.png)
 
 Mimic-cross introduces binaries running on host into the environment run by
 qemu-use-static to speed up the process. To do so, the mimic-cross image has a
-sysroot for the host architecture under /host.
+sysroot for the host architecture under /mimic-cross.
 
 This allows us to run the program faster without using QEMU instead of
 increasing the image size.\
 The image size increase can be handled by multistage build.
 
-### More details
+### What happen when run package manager
+
+1. Run in target sysroot
+2. Check installed package
+3. If supported package installed, package install in /mimic-cross sysroot.
+4. Set up for mimicking (Patch to elf RUNPATH, etc...)
+
+## Environent variables
+
+### MIMIC_CROSS_DISABLE=1
+
+When this value is set, execute only the original command by qemu and no special
+mimic-cross processing.
 
-- [apt package management in mimic-cross](docs/apt-get.md)
-- [about mimic python](docs/python3.md)
+If you run the pip command with this, you will not be able to invoke the
+installed packages in the mimic-cross environment, but you can reduce the image
+size if you are simply installing dependencies needed for the build