From 997c046dc5ee2d83be01bd7903b8b5e5e4615caf Mon Sep 17 00:00:00 2001
From: Alejandro Cabeza Romero <alex93cabeza@gmail.com>
Date: Mon, 14 Jul 2025 15:02:14 +0200
Subject: [PATCH] Improve README explaining crosscompilation for windows from
 linux.

---
 circom_circuits/Mantle/README.md | 84 ++++++++++++++++++--------------
 1 file changed, 48 insertions(+), 36 deletions(-)

diff --git a/circom_circuits/Mantle/README.md b/circom_circuits/Mantle/README.md
index a26e258..f45ca93 100644
--- a/circom_circuits/Mantle/README.md
+++ b/circom_circuits/Mantle/README.md
@@ -22,66 +22,81 @@
 3. Replace the Makefile
     The autogenerated `Makefile` does not support cross-compilation. Replace the `Makefile` contents with the following:
     ```make
-    # ========== General ==========
+# ========== General ==========
 
-    DEPS_HPP = circom.hpp calcwit.hpp fr.hpp
+DEPS_HPP = circom.hpp calcwit.hpp fr.hpp
 
-    # ========== Native Linux build ==========
-    CXX = g++
-    CXXFLAGS = -std=c++11 -O3 -I.
-    LDFLAGS = -lgmp
+# ========== Native Linux build ==========
+CXX = g++
+CXXFLAGS = -std=c++11 -O3 -I.
+LDFLAGS = -lgmp
 
-    OBJS = main.o calcwit.o fr.o pol.o
+OBJS = main.o calcwit.o fr.o pol.o
 
-    all: pol
+all: pol
 
-    %.o: %.cpp $(DEPS_HPP)
-        $(CXX) -Wno-address-of-packed-member -c $< $(CXXFLAGS)
+%.o: %.cpp $(DEPS_HPP)
+    $(CXX) -Wno-address-of-packed-member -c $< $(CXXFLAGS)
 
-    pol: $(OBJS)
-        $(CXX) -o $@ $^ $(LDFLAGS)
+pol: $(OBJS)
+    $(CXX) -o $@ $^ $(LDFLAGS)
 
-    # ========== Windows cross-compilation ==========
+# ========== Windows cross-compilation ==========
 
-    CXX_WIN = x86_64-w64-mingw32-g++
-    CC_WIN = x86_64-w64-mingw32-gcc
-    CXXFLAGS_WIN = -std=c++11 -O3 -I. -Iinclude -Duint="unsigned int" -Ideps/mman-win32
-    LDFLAGS_WIN = -L/usr/x86_64-w64-mingw32/sys-root/mingw/lib -lgmp
+CXX_WIN = x86_64-w64-mingw32-g++
+CC_WIN = x86_64-w64-mingw32-gcc
+CXXFLAGS_WIN = -std=c++11 -O3 -I. -Iinclude -Duint="unsigned int"
+LDFLAGS_WIN = -Llib -lgmp -lmman
 
-    WIN_OBJS = main.win.o calcwit.win.o fr.win.o pol.win.o mman.win.o
+WIN_OBJS = main.win.o calcwit.win.o fr.win.o pol.win.o mman.win.o
 
-    %.win.o: %.cpp $(DEPS_HPP)
-        $(CXX_WIN) -Wno-address-of-packed-member -c $< -o $@ $(CXXFLAGS_WIN)
+%.win.o: %.cpp $(DEPS_HPP)
+    $(CXX_WIN) -Wno-address-of-packed-member -c $< -o $@ $(CXXFLAGS_WIN)
 
-    mman.win.o: deps/mman-win32/mman.c
-        $(CC_WIN) -c $< -o $@
+mman.win.o: deps/mman-win32/mman.c
+    $(CC_WIN) -c $< -o $@
 
-    pol.exe: $(WIN_OBJS)
-        $(CXX_WIN) -o $@ $^ $(LDFLAGS_WIN)
+pol.exe: $(WIN_OBJS)
+    $(CXX_WIN) -o $@ $^ $(LDFLAGS_WIN)
 
-    # ========== Cleanup ==========
+# ========== Cleanup ==========
 
-    clean:
-        $(RM) *.o *.win.o pol pol.exe
+clean:
+    $(RM) *.o *.win.o pol pol.exe
     ```
 4. Install Dependencies
     1. Cross-Compiler
         ```bash
         sudo dnf install mingw64-gcc mingw64-gcc-c++ # Compiler
         ```
-    2. `sys/mman.h`
+    2. Directory structure
         ```bash
         mkdir -p include/sys
         mkdir -p deps
+        mkdir -p lib
+        ```mkdir -p include/sys
+        mkdir -p deps
+        mkdir -p lib
+
+    3. `sys/mman.h`
+        ```bash
         git clone https://github.com/alitrack/mman-win32.git deps/mman-win32
-        cp deps/mman-win32/mman.h ./sys/
+
+        # cp deps/mman-win32/mman.h ./sys/
+        ####
+        cd deps/mman-win32
+        ./configure
+        make CC=x86_64-w64-mingw32-gcc
+        cd ../..
+        cp deps/mman-win32/mman.h include/sys/
+        cp deps/mman-win32/libmman.a lib
         ```
-    3. `nlohmann/json`
+    4. `nlohmann/json`
         ```bash
         mkdir -p include/nlohmann
         wget https://raw.githubusercontent.com/nlohmann/json/develop/single_include/nlohmann/json.hpp -O include/nlohmann/json.hpp
         ```
-    4. `gmp`
+    5. `gmp`
         ```
         sudo dnf install mingw64-gmp
         ```
@@ -92,11 +107,8 @@
 6. Bundle
     1. Copy `.dll`s
         ```bash
-        cp /usr/x86_64-w64-mingw32/sys-root/mingw/bin/libgcc_s_seh-1.dll \
-           /usr/x86_64-w64-mingw32/sys-root/mingw/bin/libgmp-10.dll \
-           /usr/x86_64-w64-mingw32/sys-root/mingw/bin/libwinpthread-1.dll \
-           /usr/x86_64-w64-mingw32/sys-root/mingw/bin/libstdc++-6.dll \
-           .
+        MINGW_DLL_DIR="$(x86_64-w64-mingw32-gcc -print-sysroot)/mingw/bin"
+        cp "$MINGW_DLL_DIR"/{libgcc_s_seh-1.dll,libgmp-10.dll,libwinpthread-1.dll,libstdc++-6.dll} .
         ```
     2. Copy `.dat`
         ```