diff --git a/README.md b/README.md
index 7d8604b..9d3b28b 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,8 @@
+[![CI](https://github.com/ccc-spdm-tools/spdm-rs/actions/workflows/main.yml/badge.svg)](https://github.com/ccc-spdm-tools/spdm-rs/actions/workflows/main.yml)
+[![Deny](https://github.com/ccc-spdm-tools/spdm-rs/actions/workflows/deny.yml/badge.svg)](https://github.com/ccc-spdm-tools/spdm-rs/actions/workflows/deny.yml)
+[![Format](https://github.com/ccc-spdm-tools/spdm-rs/actions/workflows/format.yml/badge.svg)](https://github.com/ccc-spdm-tools/spdm-rs/actions/workflows/format.yml)
+[![Fuzzing](https://github.com/ccc-spdm-tools/spdm-rs/actions/workflows/fuzz.yml/badge.svg)](https://github.com/ccc-spdm-tools/spdm-rs/actions/workflows/fuzz.yml)
+
 # spdm-rs
 
 This project provides a Rust language implementation of [SPDM](https://www.dmtf.org/standards/spdm),
@@ -10,3 +15,246 @@ There are a number of use cases that benefit from including devices and accelera
 boundary of a Confidential Virtual Machine (CVM). In machine learning, for example, these
 protocols can be used to build a trusted connection between a GPU’s TEE and a CVM to accelerate
 performance.
+
+
+## Features
+
+### Specification
+
+DMTF [DSP0274](https://www.dmtf.org/dsp/DSP0274) Security Protocol and Data Model (SPDM) Specification (version [1.2.2](https://www.dmtf.org/sites/default/files/standards/documents/DSP0274_1.2.2.pdf))
+
+DMTF [DSP0277](https://www.dmtf.org/dsp/DSP0277) Secured Messages using SPDM Specification (version [1.1.1](https://www.dmtf.org/sites/default/files/standards/documents/DSP0277_1.1.1.pdf))
+
+PCIe Base Specification Version [6.0.1](https://members.pcisig.com/wg/PCI-SIG/document/18363), [6.1](https://members.pcisig.com/wg/PCI-SIG/document/19849)
+
+PCIe [DOE 1.0 ECN](https://members.pcisig.com/wg/PCI-SIG/document/14143) in PCIe 6.0, [DOE 1.1 ECN](https://members.pcisig.com/wg/PCI-SIG/document/18483) in PCIe 6.1.
+
+PCIe [CMA 1.0 ECN](https://members.pcisig.com/wg/PCI-SIG/document/14236) in PCIe 6.0, [CMA 1.1 ECN](https://members.pcisig.com/wg/PCI-SIG/document/20110) in PCIe TBD.
+
+PCIe [IDE ECN](https://members.pcisig.com/wg/PCI-SIG/document/16599) in PCIe 6.0.
+
+PCIe [TDISP ECN](https://members.pcisig.com/wg/PCI-SIG/document/18268) in PCIe 6.1.
+
+### SPDM Implemented Requests and Responses
+
+SPDM 1.0: GET_VERSION, GET_CAPABILITIES, NEGOTIATE_ALGORITHMS, GET_DIGESTS, GET_CERTIFICATE, CHALLENGE, and GET_MEASUREMENTS.
+
+SPDM 1.1: KEY_EXCHANGE, FINISH, PSK_EXCHANGE, PSK_FINISH, END_SESSION, HEARTBEAT, KEY_UPDATE messages.
+
+SPDM 1.2: Support 1.0/1.1 messages and new format. New SPDM 1.2 messages are not supported yet.
+
+SPDM 1.3: Not support yet.
+
+### SPDM Vendor Defined Message
+
+IDE_KM 1.0 in PCIe 6.0/6.1.
+
+TDISP 1.0 in PCIe 6.1.
+
+### SPDM Capability Support
+
+Requester: ENCRYPT_CAP, MAC_CAP, KEY_EX_CAP, PSK_CAP, HBEAT_CAP, KEY_UPD_CAP, HANDSHAKE_IN_THE_CLEAR_CAP.
+
+Responder: CERT_CAP, CHAL_CAP, MEAS_CAP_NO_SIG, MEAS_CAP_SIG, MEAS_FRESH_CAP, ENCRYPT_CAP, MAC_CAP, KEY_EX_CAP, PSK_CAP_WITHOUT_CONTEXT, PSK_CAP_WITH_CONTEXT, HBEAT_CAP, KEY_UPD_CAP, HANDSHAKE_IN_THE_CLEAR_CAP.
+
+### SPDM Cryptographic Algorithm Support
+
+It depends on crypto wrapper. Current support algorithms:
+* Hash: SHA2(256/384/512)
+* Signature: RSA-SSA(2048/3072/4096) / RSA-PSS(2048/3072/4096) / ECDSA (P256/P384)
+* KeyExchange: ECDHE(P256/P384)
+* AEAD: AES_GCM(128/256) / ChaCha20Poly1305
+
+## Documentation
+All documents are put at [doc](./doc/) folder.
+
+## Build Rust SPDM
+
+### Checkout repo
+```
+git clone https://github.com/intel/rust-spdm.git
+git submodule update --init --recursive
+```
+
+Then patch the ring/webpki.
+```
+sh_script/pre-build.sh
+```
+
+### Tools
+
+1. Install [RUST](https://www.rust-lang.org/)
+
+Please use nightly-2023-08-28.
+
+2. Install [NASM](https://www.nasm.us/)
+
+Please make sure nasm can be found in PATH.
+
+3. Install [LLVM](https://llvm.org/)
+
+Please make sure clang can be found in PATH.
+
+4. Install [Perl](https://www.perl.org/)
+
+    1.	This is for crate ring
+    2.	This is for windows
+
+Please make sure perl can be found in PATH.
+
+
+Unset env (CC and AR):
+```
+export CC=
+export AR=
+```
+Set the following environment variables:
+```
+export AR_x86_64_unknown_none=llvm-ar
+export CC_x86_64_unknown_none=clang
+```
+
+### Build OS application
+
+Enter linux shell or mingw shell (e.g. git bash) in windows.
+```
+cargo clippy
+cargo fmt
+cargo build
+```
+
+### Build async `no_std` spdm
+```
+pushd spdmlib
+cargo build -Z build-std=core,alloc,compiler_builtins --target x86_64-unknown-none --release --no-default-features --features="spdm-ring"
+```
+
+### Build sync `no_std` spdm
+```
+pushd spdmlib
+cargo build -Z build-std=core,alloc,compiler_builtins --target x86_64-unknown-none --release --no-default-features --features="spdm-ring,is_sync"
+```
+
+## Run Rust SPDM emulator
+
+### Run emulator with default feature
+
+Open one command windows and run:
+```
+cargo run -p spdm-responder-emu --no-default-features --features "spdm-ring,hashed-transcript-data,async-executor"
+```
+
+Open another command windows and run:
+```
+cargo run -p spdm-requester-emu --no-default-features --features "spdm-ring,hashed-transcript-data,async-executor"
+```
+
+### Run emulator with selected feature
+
+The following list shows the supported combinations for both spdm-requester-emu and spdm-responder-emu
+
+
+| Features                                           | CryptoLibrary | Hashed transcript data support | sync/async             | notes                                                                                                           |
+|----------------------------------------------------|---------------|--------------------------------|------------------------|-----------------------------------------------------------------------------------------------------------------|
+| spdm-ring,is_sync                                  | ring          | No                             | sync                   | use ring as crypto library with hashed-transcript-data disabled, sync version.                                  |
+| spdm-ring,hashed-transcript-data,is_sync           | ring          | Yes                            | sync                   | use ring as crypto library with hashed-transcript-data enabled, sync version.                                   |
+| spdm-ring,hashed-transcript-data,async-tokio       | ring          | Yes                            | tokio async runtime    | use ring as crypto library with hashed-transcript-data enabled, async version, use tokio as async runtime       |
+| spdm-mbedtls,is_sync                               | mbedtls       | No                             | sync                   | use mbedtls as crypto library with hashed-transcript-data disabled, sync version.                               |
+| spdm-mbedtls,hashed-transcript-data,is_sync        | mbedtls       | Yes                            | sync                   | use mbedtls as crypto library with hashed-transcript-data enabled, sync version.                                |
+| spdm-mbedtls,hashed-transcript-data,async-executor | mbedtls       | Yes                            | executor async runtime | use mbedtls as crypto library with hashed-transcript-data enabled, async version, use executor as async runtime |
+
+
+For example, run the emulator with spdm-ring enabled and without hashed-transcript-data enabled, and use executor as async runtime. 
+Open one command windows and run:
+```
+cargo run -p spdm-responder-emu --no-default-features --features "spdm-ring,async-executor "
+```
+
+run the emulator with spdm-mbedtls enabled and with hashed-transcript-data enabled, and use tokio as async runtime.  
+Open another command windows and run:
+```
+cargo run -p spdm-requester-emu --no-default-features --features "spdm-mbedtls,hashed-transcript-data,async-tokio"
+```
+
+run the emulator with spdm-mbedtls enabled and with hashed-transcript-data enabled, and without using async style.  
+Open another command windows and run:
+```
+cargo run -p spdm-requester-emu --no-default-features --features "spdm-mbedtls,hashed-transcript-data,is_sync"
+```
+
+NOTE: In order to run the emu without hashed-transcript-data, please change `max_cert_chain_data_size` in `spdmlib/etc/config.json` from `4096` to `3500`.
+
+### Cross test with [spdm_emu](https://github.com/DMTF/spdm-emu)
+Open one command windows in workspace and run:
+
+```
+git clone https://github.com/DMTF/spdm-emu.git
+cd spdm-emu
+git submodule update --init --recursive
+mkdir build
+cd build
+cmake -G"NMake Makefiles" -DARCH=<x64|ia32> -DTOOLCHAIN=<toolchain> -DTARGET=<Debug|Release> -DCRYPTO=<mbedtls|openssl> ..
+nmake copy_sample_key
+nmake
+```
+
+Test rust-spdm as requester:
+
+1. run libspdm in spdm-emu as responder:
+```
+cd bin
+spdm_responder_emu.exe --trans PCI_DOE
+```
+
+2. run rust-spdm-emu as requester:
+```
+cargo run -p spdm-requester-emu --no-default-features --features "spdm-ring,hashed-transcript-data,async-executor "
+```
+
+Test rust-spdm as responder:
+
+1. run rust-spdm-emu as Test rust-spdm as responder:
+```
+cargo run -p spdm-responder-emu --no-default-features --features "spdm-ring,hashed-transcript-data,async-executor "
+```
+
+2. run libspdm in spdm-emu as requester:
+```
+cd bin
+spdm_requester_emu.exe --trans PCI_DOE --exe_conn DIGEST,CERT,CHAL,MEAS --exe_session KEY_EX,PSK,KEY_UPDATE,HEARTBEAT,MEAS,DIGEST,CERT
+```
+
+### Run test cases
+
+Setting up enough stack before running tests
+
+```
+export RUST_MIN_STACK=10485760
+```
+
+Test with hashed-transcript-data:
+```
+cargo test --no-default-features --features "spdmlib/std,spdmlib/spdm-ring,spdmlib/hashed-transcript-data,async-executor" -- --test-threads=1
+```
+
+Test without hashed-transcript-data:
+```
+cargo test --no-default-features --features "spdmlib/std,spdmlib/spdm-ring,async-executor" -- --test-threads=1
+```
+
+To run a specific test, use `cargo test <test_func_name>`
+
+To run test with println!() message, use `cargo test -- --nocapture`
+
+## Collect memory usage
+
+To collect memory usage, use
+
+```
+python sh_script/collect_memory_usage.py
+```
+
+This script will display the peak memory used by spdm-emu
+
+## Known limitation
+This package is only the sample code to show the concept. It does not have a full validation such as robustness functional test and fuzzing test. It does not meet the production quality yet. Any codes including the API definition, the libary and the drivers are subject to change.