From 49e0d547ca2d2d2ecd0d02a11d14b142f12c40c3 Mon Sep 17 00:00:00 2001
From: "M.Amin Rayej" <m.amin.rayej@gmail.com>
Date: Tue, 17 Dec 2024 11:04:29 +0330
Subject: [PATCH] add instructions for Makefile based projects

---
 README.md | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/README.md b/README.md
index 2ede5150..f9b3b309 100644
--- a/README.md
+++ b/README.md
@@ -59,6 +59,7 @@ replicate its build steps.
 
 # Usage
 
+### CMAKE based projects
 For building CMake projects, a toolchain file is included in the released sysroot
 at `wasix-sysroot/clang-wasm.cmake_toolchain`. In addition to specifying the 
 toolchain:
@@ -67,6 +68,29 @@ toolchain:
   linker package. It should be in the `PATH`.
 * `CMAKE_TOOLCHAIN_FILE` and `CMAKE_SYSROOT` should both be set by you.
 
+For an example of a CMAKE based project being built for WASIX, please read the (notes)[https://github.com/wasix-org/llvm-project/blob/llvmorg-16.0.0-wasix/NOTES-WASIX.md] 
+on how to build LLVM/clang for WASIX.
+
+### Makefile based projects
+For building `Makefile` based projects, there are certain compiler and linker flags that
+need to be passed to as env vars:
+```
+CFLAGS="--target=wasm32-wasi --sysroot=$SYSROOT -matomics -mbulk-memory -mmutable-globals -pthread -mthread-model posix -ftls-model=local-exec \
+    -fno-trapping-math -D_WASI_EMULATED_MMAN -D_WASI_EMULATED_SIGNAL -D_WASI_EMULATED_PROCESS_CLOCKS \
+    -g -flto -O2"
+
+CXXFLAGS="--target=wasm32-wasi --sysroot=$SYSROOT -matomics -mbulk-memory -mmutable-globals -pthread -mthread-model posix -ftls-model=local-exec \
+    -fno-trapping-math -D_WASI_EMULATED_MMAN -D_WASI_EMULATED_SIGNAL -D_WASI_EMULATED_PROCESS_CLOCKS \
+    -g -flto -fno-exceptions -O2"
+
+LDFLAGS="-Wl,--shared-memory -Wl,--max-memory=4294967296 -Wl,--import-memory -Wl,--export-dynamic \
+    -Wl,--export=__heap_base -Wl,--export=__stack_pointer -Wl,--export=__data_end -Wl,--export=__wasm_init_tls \
+    -Wl,--export=__wasm_signal -Wl,--export=__tls_size -Wl,--export=__tls_align -Wl,--export=__tls_base \
+    -lwasi-emulated-mman -flto -g -Wl,-z,stack-size=8388608 -Wl,--error-limit=0"
+```
+For an example of a Makefile based project being built for WASIX, please read the (notes)[https://github.com/wasix-org/openssl/blob/master/NOTES-WASIX.md] 
+on how to build OpenSSL for WASIX.
+
 The WASIX-specific tests and script in `test/wasix` can serve as examples for how
 to set this up.