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, 114 insertions, 0 deletions

diff --git a/tests/testlib.c b/tests/testlib.c
new file mode 100644
index 00000000..2eaeb591
--- /dev/null
+++ b/tests/testlib.c
@@ -0,0 +1,114 @@
+/*
+ *  Copyright (C) 2024 Free Software Foundation
+ *
+ * This program is free software ; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation ; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY ; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with the program ; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <testlib.h>
+
+#include <device/cons.h>
+#include <mach/kern_return.h>
+#include <mach/message.h>
+#include <mach/mig_errors.h>
+#include <mach/vm_param.h>
+
+#include <mach.user.h>
+#include <mach_host.user.h>
+
+
+static int argc = 0;
+static char *argv_unknown[] = {"unknown", "m1", "123", "456"};
+static char **argv = argv_unknown;
+static char **envp = NULL;
+static int envc = 0;
+
+static mach_port_t host_priv_port = 1;
+static mach_port_t device_master_port = 2;
+
+void cnputc(char c, vm_offset_t cookie)
+{
+    char buf[2] = {c, 0};
+    mach_print(buf);
+}
+
+mach_port_t host_priv(void)
+{
+    return host_priv_port;
+}
+
+mach_port_t device_priv(void)
+{
+    return device_master_port;
+}
+
+void halt()
+{
+  int ret = host_reboot(host_priv_port, 0);
+  ASSERT_RET(ret, "host_reboot() failed!");
+  while (1)
+    ;
+}
+
+int msleep(uint32_t timeout)
+{
+  mach_port_t recv = mach_reply_port();
+  return mach_msg(NULL, MACH_RCV_MSG|MACH_RCV_TIMEOUT|MACH_RCV_INTERRUPT,
+                  0, 0, recv, timeout, MACH_PORT_NULL);
+}
+
+const char* e2s(int err)
+{
+  const char* s = e2s_gnumach(err);
+  if (s != NULL)
+    return s;
+  else
+    switch (err)
+      {
+      default: return "unknown";
+      }
+}
+
+/*
+ * Minimal _start() for test modules, we just take the arguments from the
+ * kernel, call main() and reboot. As in glibc, we expect the argument pointer
+ * as a first asrgument.
+ */
+void __attribute__((used, retain))
+c_start(void **argptr)
+{
+  intptr_t* argcptr = (intptr_t*)argptr;
+  argc = argcptr[0];
+  argv = (char **) &argcptr[1];
+  envp = &argv[argc + 1];
+  envc = 0;
+
+  while (envp[envc])
+    ++envc;
+
+  mach_atoi(argv[1], &host_priv_port);
+  mach_atoi(argv[2], &device_master_port);
+
+  printf("started %s", argv[0]);
+  for (int i=1; i<argc; i++)
+  {
+      printf(" %s", argv[i]);
+  }
+  printf("\n");
+
+  int ret = main(argc, argv, envc, envp);
+
+  printf("%s: test %s exit code %x\n", TEST_SUCCESS_MARKER, argv[0], ret);
+  halt();
+}