trying to get a version to compile with gcc 10

newlib/README.md

@@ -8,6 +8,22 @@ the position independent code that Tock applications require.
 Compiling a new version of Newlib
 ---------------------------------
 
+This folder contains scripts to build and package newlib for libtock-c. Note,
+however, that successfully building usable newlib images is heavily dependent on
+the specific toolchain (both ARM and RISC-V) that you have installed on your
+machine. Specifically, we are aware of two issues that can arise:
+
+1. For ARM, the specific architectures that your GCC was compiled with support
+   for are the versions of newlib that will be compiled. As far as I know this
+   is not configurable. If you run `arm-none-eabi-gcc -print-multi-lib` you will
+   see the architectures.
+2. For RISC-V, using a new toolchain (e.g. gcc 13) to compile the libraries, and
+   then using those libraries with an older toolchain (e.g. gcc 10) seems to
+   cause failures.
+
+
+### Simple Directions
+
 In the `Makefile`, edit the variable `NEWLIB_VERSION` with the version
 you want to compile. The releases are listed
 [here](http://sourceware.org/pub/newlib/).
@@ -19,3 +35,5 @@ Then:
 When the build finishes (it takes a while), a zip folder named
 `libtock-newlib-<version>.zip` will contain the built libraries. You can move
 that folder to the `libtock-c/lib` directory to use the new version of newlib.
+
+

newlib/build-arm.sh

@@ -19,6 +19,10 @@ if ! arm-none-eabi-gcc --print-multi-lib | grep -q 'v7e-m/nofp'; then
   exit -1
 fi
 
+# Need to remove the `v5te` targets from the output of `-print-multi-lib` (if
+# they exist) as they are ancient and fail to compile.
+sed -i.bak 's/--print-multi-lib/--print-multi-lib | grep -v v5te/' $NEWLIB_SRC_DIR/config-ml.in
+
 $NEWLIB_SRC_DIR/configure --target=arm-none-eabi \
   --disable-newlib-supplied-syscalls \
   --disable-nls \