README.md updated. crossbuild tools don't work on Ubuntu 20.04 - compiler internal...

diff --git a/.gitignore b/.gitignore
index 8130ae6..eae354e 100644 (file)
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,5 @@
 bin/
 .project
 .vscode/
+*.o
+/lib/lib

diff --git a/README.md b/README.md
index 1dca6b9..cc56b56 100755 (executable)
--- a/README.md
+++ b/README.md
@@ -1,5 +1,14 @@
 # lpunpack and lpmake
-To cross-compile you need `crossbuild-essential-arm64`/`crossbuild-essential-armel`/`crossbuild-essential-armhf` (sudo apt install $package).
+To compile x86_64 you need:
+- clang (sudo apt install clang)
+- zlib (sudo apt install zlib1g-dev)
+
+To cross-compile you need:
+- Ubuntu 22.04: `crossbuild-essential-arm64`/`crossbuild-essential-armel`/`crossbuild-essential-armhf` (sudo apt install $package).
+- Ubuntu 20.04: `sudo apt install gcc-10-aarch64-linux-gnu` and `sudo apt install g++-aarch64-linux-gnu`
+
+On Ubuntu 20.04 crossbuild-essential-arm64 uses gcc 9.x  which gives an internal error during build. This is why gcc-10 version has to be installed explicitly.
+
 
 build:
 ./make.sh $ARCH