add basic user-space tests with qemu

* configure.ac: move test fragment to have USER32
* tests/Makefrag.am: add user tests
* tests/README: add basic info on how to run and debug user tests
* tests/configfrag.ac: allow the test compiler/flags to be
  autoconfigured or customized
* tests/grub.cfg.single.template: add minimal grub config to boot a
  module
* tests/include/device/cons.h: add a simplified version of
  device/cons.h usable for tests
* tests/include/kern/printf.h: symlink to kern/printf.h
* tests/include/mach/mig_support.h: add basic version for user-space
  tests
* tests/include/syscalls.h: add prototypes for syscalls used in tests.
* tests/include/testlib.h: add definitions for common test
  functionalities
* tests/include/util/atoi.h: symlink to util/atoi.h
* tests/run-qemu.sh.template: add a simple qemu test runner
* tests/start.S: add arch-specific entry point
* tests/syscalls.S: generate syscalls entry points
* tests/test-hello.c: add basic smoke test
* tests/testlib.c: add the minimal functionality to run a user-space
  executable and reboot the system, and some test helpers.
* tests/user-qemu.mk: add rules to build simple user-space test
  modules, including generating mig stubs. The tests reuse some kernel
  code (like printf(), mach_atoi(), mem*(), str*() functions) so we can
  use the freestanding environment and not depend on glibc.
Message-ID: <20240111210907.419689-1-luca@orpolo.org>

1 files changed, 37 insertions, 0 deletions

diff --git a/tests/README b/tests/README
new file mode 100644
index 00000000..3dacc184
--- /dev/null
+++ b/tests/README
@@ -0,0 +1,37 @@
+
+There are some basic tests that can be run qith qemu. You can run all the tests with
+
+    $ make check
+
+or selectively with:
+
+    $ make run-hello
+
+Also, you can debug the existing tests, or a new one, by starting on one shell
+
+    $ make debug-hello
+
+and on another shell you can attach with gdb, load the symbols of the
+bootstrap module and break on its _start():
+
+    $ gdb gnumach
+    ...
+    (gdb) target remote :1234
+    ...
+    (gdb) b setup_main
+    Breakpoint 11 at 0xffffffff81019d60: file ../kern/startup.c, line 98.
+    (gdb) c
+    Continuing.
+
+    Breakpoint 11, setup_main () at ../kern/startup.c:98
+    98		cninit();
+    (gdb) add-symbol-file ../gnumach/build-64/module-task
+    Reading symbols from ../gnumach/build-64/module-task...
+    (gdb) b _start
+    Breakpoint 12 at 0x40324a: _start. (2 locations)
+    (gdb) c
+    Continuing.
+
+    Breakpoint 12, _start () at ../tests/testlib.c:96
+    96	{
+    (gdb)