gem5 semihosting

README.adoc

@@ -747,6 +747,7 @@ Alternatively, for the sake of tab completion, we also accept full paths inside
 To use gem5 instead of QEMU do:
 
 ....
+patch -d "$(./getvar gem5_src_dir)" -p 1 < patches/manual/gem5-semihost.patch && \
 ./configure --baremetal --gem5             && \
 ./build-gem5 --arch arm                    && \
 ./build-crosstool-ng --arch arm            && \
@@ -761,10 +762,9 @@ and then <<qemu-buildroot-setup,as usual>> open a shell with:
 ./gem5-shell
 ....
 
-TODO:
+TODO: the carriage returns are a bit different than in QEMU, see: <<gem5-baremetal-carriage-return>>.
 
-* the carriage returns are a bit different than in QEMU, see: <<gem5-baremetal-carriage-return>>.
-* semihosting is disabled, and all examples that rely on it fail, including  how to enable it? See <<gem5-semihosting>>
+The semihosting patch is required to enable <<semihosting>>, on which base functionality such as `exit()` depends, see also: https://stackoverflow.com/questions/52475268/how-to-enable-arm-semihosting-in-gem5/52475269#52475269
 
 Note that `./build-baremetal` requires the `--gem5` option, and generates separate executable images for both, as can be seen from:
 
@@ -9821,16 +9821,6 @@ Bibliography:
 * https://stackoverflow.com/questions/31990487/how-to-cleanly-exit-qemu-after-executing-bare-metal-program-without-user-interve/40957928#40957928
 * https://balau82.wordpress.com/2010/11/04/qemu-arm-semihosting/
 
-==== gem5 semihosting
-
-TODO how to enable it? <<config-ini>> contains:
-
-....
-root.system.semihosting=Null
-....
-
-and there are no hits under `configs/`.
-
 === gem5 baremetal carriage return
 
 TODO: our example is printing newlines without automatic carriage return `\r` as in: