baremetal: build userland programs using userland_and_baremetal instead of symlinks

Otherwise I'll go crazy with symlink action.

README.adoc

@@ -1206,35 +1206,6 @@ The terminal prints:
 hello
 ....
 
-Now let's run link:baremetal/arch/aarch64/add.S[]:
-
-....
-./run --arch aarch64 --baremetal baremetal/arch/aarch64/add.S
-....
-
-This time, the terminal does not print anything, which indicates success.
-
-If you look into the source, you will see that we just have an assertion there.
-
-You can see a sample assertion fail in link:baremetal/interactive/assert_fail.c[]:
-
-....
-./run --arch aarch64 --baremetal baremetal/interactive/assert_fail.c
-....
-
-and the terminal contains:
-
-....
-lkmc_test_fail
-error: simulation error detected by parsing logs
-....
-
-and the exit status of our script is 1:
-
-....
-echo $?
-....
-
 To modify a baremetal program, simply edit the file, e.g.
 
 ....
@@ -1252,17 +1223,44 @@ and rebuild:
 
 `./build-baremetal` uses crosstool-NG, and so it must be preceded by link:build-crosstool-ng[], which `./build qemu-baremetal` also calls.
 
-Alternatively, for the sake of tab completion, we also accept relative paths inside `baremetal/`, for example the following also work:
+
+Now let's run link:baremetal/arch/aarch64/add.S[]:
 
 ....
-./run --arch aarch64 --baremetal baremetal/c/hello.c
 ./run --arch aarch64 --baremetal baremetal/arch/aarch64/add.S
 ....
 
-Absolute paths however are used as is and must point to the actual executable:
+This time, the terminal does not print anything, which indicates success: if you look into the source, you will see that we just have an assertion there.
+
+You can see a sample assertion fail in link:baremetal/interactive/assert_fail.c[]:
 
 ....
-./run --arch aarch64 --baremetal "$(./getvar --arch aarch64 baremetal_build_dir)/hello.elf"
+./run --arch aarch64 --baremetal userland/c/assert_fail.c
+....
+
+and the terminal contains:
+
+....
+lkmc_test_fail
+error: simulation error detected by parsing logs
+....
+
+and the exit status of our script is 1:
+
+....
+echo $?
+....
+
+As suggested by the above example, several of the <<userland-content,userland examples>> can also be run in baremetal! This is largely due to the <<about-the-baremetal-setup,awesomeness of Newlib>>.
+
+The examples that work include most <<c,C examples>> that don't rely on complicated syscalls such as threads, and almost all the <<userland-assembly>> examples.
+
+The exact list of userland programs that work in baremetal is specified in <<path-properties>> with the `baremetal` property.
+
+You can run all the baremetal examples in one go and check that all assertions passed with:
+
+....
+./test-baremetal --arch aarch64
 ....
 
 To use gem5 instead of QEMU do:

baremetal/c/add.c

@@ -1 +0,0 @@
-../../lkmc/c/add.c

baremetal/c/add.py

@@ -1 +0,0 @@
-../../lkmc/c/add.py

baremetal/c/assert_fail.c

@@ -1 +0,0 @@
-../../lkmc/c/assert_fail.c

baremetal/c/hello.c

@@ -1 +0,0 @@
-../../lkmc/c/hello.c

baremetal/c/infinite_loop.c

@@ -1 +0,0 @@
-../../lkmc/c/infinite_loop.c

baremetal/c/stderr.c

@@ -1 +0,0 @@
-../../lkmc/c/stderr.c

baremetal/lib/aarch64.S

@@ -20,6 +20,7 @@ mystart:
     bl on_exit
 
     /* Run main. */
+    mov x0, 0
     bl main
 
     /* If main returns, exit. */

baremetal/lib/arm.S

@@ -10,6 +10,7 @@ mystart:
     bl on_exit
 
     /* Run main. */
+    mov r0, 0
     bl main
 
     /* If main returns, exit. */

build-baremetal

@@ -14,6 +14,7 @@ class Main(common.BuildCliFunction):
             description='''\
 Build the baremetal examples with crosstool-NG.
 ''',
+            is_baremetal=True,
             supported_archs=common.consts['crosstool_ng_supported_archs']
         )
         self._add_argument('--ccflags')
@@ -137,7 +138,10 @@ Build the baremetal examples with crosstool-NG.
 
     def setup_one(self):
         self.env['targets'] = self.resolve_targets(
-            self.env['baremetal_source_dir'],
+            [
+                self.env['baremetal_source_dir'],
+                self.env['userland_source_dir']
+            ],
             self.env['targets']
         )
 

build-userland

@@ -15,7 +15,7 @@ class Main(common.BuildCliFunction):
             kwargs['description'] = '''\
 Build our compiled userland examples.
 '''
-        super().__init__(*args, **kwargs)
+        super().__init__(*args, is_userland=True, **kwargs)
         self._add_argument('--ccflags')
         self._add_argument('--force-rebuild')
         self._add_argument('--optimization-level')
@@ -109,7 +109,7 @@ Default: build all examples that have their package dependencies met, e.g.:
 
     def setup_one(self):
         self.env['targets'] = self.resolve_targets(
-            self.env['userland_source_dir'],
+            [self.env['userland_source_dir']],
             self.env['targets']
         )
 

common.py

@@ -162,6 +162,7 @@ class LkmcCliFunction(cli_function.CliFunction):
     def __init__(
         self,
         *args,
+        is_baremetal=False,
         is_userland=False,
         defaults=None,
         supported_archs=None,
@@ -175,7 +176,8 @@ class LkmcCliFunction(cli_function.CliFunction):
         kwargs['extra_config_params'] = os.path.basename(inspect.getfile(self.__class__))
         if defaults is None:
             defaults = {}
-        self._is_userland = is_userland
+        self.is_baremetal = is_baremetal
+        self.is_userland = is_userland
         self._defaults = defaults
         self._is_common = True
         self._common_args = set()
@@ -1035,8 +1037,12 @@ lunch aosp_{}-eng
             self._common_args.add(key)
         super().add_argument(*args, **kwargs)
 
-    def assert_is_subpath(self, subpath, parent):
+    def assert_is_subpath(self, subpath, parents):
-        if not self.is_subpath(subpath, parent):
+        is_subpath = False
+        for parent in parents:
+            if self.is_subpath(subpath, parent):
+                is_subpath = True
+        if not is_subpath:
             raise Exception(
                 'Can only accept targets inside {}, given: {}'.format(
                     parent,
@@ -1204,7 +1210,7 @@ lunch aosp_{}-eng
                                 continue
                             else:
                                 raise Exception('native emulator only supported in if target arch == host arch')
-                        if env['userland'] is None and not self._is_userland:
+                        if env['userland'] is None and not self.is_userland:
                             if real_all_emulators:
                                 continue
                             else:
@@ -1346,13 +1352,13 @@ lunch aosp_{}-eng
         else:
             return in_path
 
-    def resolve_targets(self, source_dir, targets):
+    def resolve_targets(self, source_dirs, targets):
         if not targets:
-            targets = [source_dir]
+            targets = source_dirs.copy()
         new_targets = []
         for target in targets:
-            target = self.toplevel_to_source_dir(target, source_dir)
+            target = self.toplevel_to_source_dir(target, source_dirs)
-            self.assert_is_subpath(target, source_dir)
+            self.assert_is_subpath(target, source_dirs)
             new_targets.append(target)
         return new_targets
 
@@ -1386,10 +1392,10 @@ lunch aosp_{}-eng
         '''
         pass
 
-    def toplevel_to_source_dir(self, path, source_dir):
+    def toplevel_to_source_dir(self, path, source_dirs):
         path = os.path.abspath(path)
         if path == self.env['root_dir']:
-            return source_dir
+            return source_dirs
         else:
             return path
 
@@ -1491,7 +1497,12 @@ https://github.com/cirosantilli/linux-kernel-module-cheat#gem5-debug-build
             dirpath_relative_root,
             in_basename
         ))
-        if my_path_properties.should_be_built(self.env, link):
+        if my_path_properties.should_be_built(
+            self.env,
+            link,
+            is_baremetal=self.is_baremetal,
+            is_userland=self.is_userland
+        ):
             if extra_objs is None:
                 extra_objs= []
             if link:

lkmc/c/add.c

@@ -1,13 +0,0 @@
-#include <assert.h>
-
-int main(void) {
-    int i, j, k;
-    i = 1;
-    /* test-gdb-op1 */
-    j = 2;
-    /* test-gdb-op2 */
-    k = i + j;
-    /* test-gdb-result */
-    if (k != 3)
-        assert(0);
-}

lkmc/c/add.py

@@ -1,9 +0,0 @@
-def test(self):
-    self.sendline('tbreak main')
-    self.sendline('continue')
-    self.continue_to('op1')
-    assert self.get_int('i') == 1
-    self.continue_to('op2')
-    assert self.get_int('j') == 2
-    self.continue_to('result')
-    assert self.get_int('k') == 3

lkmc/c/assert_fail.c

@@ -1,18 +0,0 @@
-/* Let's see what happens when an assert fails.
- *
- * Outcome on Ubuntu 19.04 shows the failure line:
- *
- *     assert_fail.out: /path/to/linux-kernel-module-cheat/userland/c/assert_fail.c:15: main: Assertion `0' failed.
- *
- * and exit status 134 == 128 + 6, which corresponds to SIGABORT (6).
- */
-
-#include <assert.h>
-#include <stdlib.h>
-#include <stdio.h>
-
-int main(void) {
-    assert(0);
-    puts("here");
-    return EXIT_SUCCESS;
-}

lkmc/c/getchar.c

@@ -1,21 +0,0 @@
-/* Get on character from stdin, and then print it back out.
- *
- * Same as getc(stdin).
- *
- * You have to press enter for the character to go through:
- * https://stackoverflow.com/questions/1798511/how-to-avoid-pressing-enter-with-getchar
- *
- * Used at:
- * https://stackoverflow.com/questions/556405/what-do-real-user-and-sys-mean-in-the-output-of-time1/53937376#53937376
- */
-
-#include <stdio.h>
-#include <stdlib.h>
-
-int main(void) {
-    char c;
-    printf("enter a character: ");
-    c = getchar();
-    printf("you entered: %c\n", c);
-    return EXIT_SUCCESS;
-}

lkmc/c/hello.c

@@ -1,9 +0,0 @@
-/* Print hello to stdout ;-) */
-
-#include <stdio.h>
-#include <stdlib.h>
-
-int main(void) {
-    puts("hello");
-    return EXIT_SUCCESS;
-}

lkmc/c/infinite_loop.c

@@ -1,29 +0,0 @@
-/* Loop infinitely. Print an integer whenever a period is reached:
- *
- * ....
- * ./infinite_loop [period]
- * ....
- */
-
-#include <inttypes.h>
-#include <stdint.h>
-#include <stdio.h>
-#include <stdlib.h>
-
-int main(int argc, char **argv) {
-    uintmax_t i, j, period;
-    if (argc > 1) {
-        period = strtoumax(argv[1], NULL, 10);
-    } else {
-        period = 100000000;
-    }
-    i = 0;
-    j = 0;
-    while (1) {
-        i++;
-        if (i % period == 0) {
-            printf("%ju\n", j);
-            j++;
-        }
-    }
-}

lkmc/c/stderr.c

@@ -1,7 +0,0 @@
-/* Print hello to stderr. */
-
-#include <stdio.h>
-
-int main(void) {
-    fputs("hello\n", stderr);
-}

path_properties.py

@@ -9,6 +9,8 @@ class PathProperties:
     default_cxx_std = 'c++17'
     default_properties = {
         'allowed_archs': None,
+        # Examples that can be built in baremetal.
+        'baremetal': False,
         'c_std': default_c_std,
         'cc_flags': [
             '-Wall', LF,
@@ -68,6 +70,8 @@ class PathProperties:
         # Aruments added automatically to run when running tests,
         # but not on manual running.
         'test_run_args': {},
+        # Examples that can be built in userland.
+        'userland': False,
     }
 
     '''
@@ -93,7 +97,13 @@ class PathProperties:
     def set_path_components(self, path_components):
         self.path_components = path_components
 
-    def should_be_built(self, env, link=False):
+    def should_be_built(
+        self,
+        env,
+        link=False,
+        is_baremetal=False,
+        is_userland=False,
+    ):
         if len(self.path_components) > 1 and \
                 self.path_components[1] == 'libs' and \
                 not env['package_all'] and \
@@ -105,6 +115,10 @@ class PathProperties:
                 self['allowed_archs'] is None or
                 env['arch'] in self['allowed_archs']
             ) and \
+            (
+                (    is_userland and self['userland'] ) or
+                (not is_baremetal and self['baremetal'])
+            ) and \
             not (
                 link and
                 self['no_executable']
@@ -203,6 +217,7 @@ gnu_extension_properties = {
     'cxx_std': 'gnu++17'
 }
 freestanding_properties = {
+    'baremetal': False,
     'cc_flags': [
         '-ffreestanding', LF,
         '-nostdlib', LF,
@@ -216,6 +231,7 @@ path_properties_tuples = (
     {
         'baremetal': (
             {
+                'baremetal': True,
                 'extra_objs_baremetal_bootloader': True,
                 'extra_objs_lkmc_common': True,
             },
@@ -257,13 +273,6 @@ path_properties_tuples = (
                         )
                     }
                 ),
-                'c': (
-                    {},
-                    {
-                        'assert_fail.c': {'exit_status': 134},
-                        'infinite_loop.c': {'more_than_1s': True},
-                    }
-                ),
                 'exit1.c': {'exit_status': 1},
                 'lib': {'no_executable': True},
                 'getchar.c': {'interactive': True},
@@ -271,6 +280,10 @@ path_properties_tuples = (
                 'return2.c': {'exit_status': 2},
             }
         ),
+        'lkmc.c': {
+            'baremetal': True,
+            'userland': True,
+        }
         'userland': (
             {
                 'cc_flags': [
@@ -279,10 +292,12 @@ path_properties_tuples = (
                 'cc_flags_after': [
                     '-pthread', LF,
                 ],
+                'userland': True,
             },
             {
                 'arch': (
                     {
+                        'baremetal': True,
                         'extra_objs_lkmc_common': True,
                     },
                     {
@@ -366,7 +381,9 @@ path_properties_tuples = (
                     }
                 ),
                 'c': (
-                    {},
+                    {
+                        'baremetal': True,
+                    },
                     {
                         'assert_fail.c': {
                             'exit_status': 134,

test-baremetal

@@ -11,6 +11,7 @@ import thread_pool
 class Main(common.TestCliFunction):
     def __init__(self):
         super().__init__(
+            is_baremetal=True,
             supported_archs=common.consts['crosstool_ng_supported_archs'],
         )
         self.add_argument(
@@ -23,7 +24,10 @@ If given, run only the given tests. Otherwise, run all tests.
 
     def setup_one(self):
         self.env['tests'] = self.resolve_targets(
-            self.env['baremetal_source_dir'],
+            [
+                self.env['baremetal_source_dir'],
+                self.env['userland_source_dir']
+            ],
             self.env['tests']
         )
 

test-user-mode

@@ -28,7 +28,7 @@ If given, run only the given tests. Otherwise, run all tests.
 
     def setup_one(self):
         self.env['tests'] = self.resolve_targets(
-            self.env['userland_source_dir'],
+            [self.env['userland_source_dir']],
             self.env['tests']
         )
 

userland/c/add.c

@@ -1 +0,0 @@
-../../lkmc/c/add.c

userland/c/add.c

@@ -0,0 +1,13 @@
+#include <assert.h>
+
+int main(void) {
+    int i, j, k;
+    i = 1;
+    /* test-gdb-op1 */
+    j = 2;
+    /* test-gdb-op2 */
+    k = i + j;
+    /* test-gdb-result */
+    if (k != 3)
+        assert(0);
+}

userland/c/add.py

@@ -1 +0,0 @@
-../../lkmc/c/add.py

userland/c/add.py

@@ -0,0 +1,9 @@
+def test(self):
+    self.sendline('tbreak main')
+    self.sendline('continue')
+    self.continue_to('op1')
+    assert self.get_int('i') == 1
+    self.continue_to('op2')
+    assert self.get_int('j') == 2
+    self.continue_to('result')
+    assert self.get_int('k') == 3

userland/c/assert_fail.c

@@ -1 +0,0 @@
-../../lkmc/c/assert_fail.c

userland/c/assert_fail.c

@@ -0,0 +1,18 @@
+/* Let's see what happens when an assert fails.
+ *
+ * Outcome on Ubuntu 19.04 shows the failure line:
+ *
+ *     assert_fail.out: /path/to/linux-kernel-module-cheat/userland/c/assert_fail.c:15: main: Assertion `0' failed.
+ *
+ * and exit status 134 == 128 + 6, which corresponds to SIGABORT (6).
+ */
+
+#include <assert.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+int main(void) {
+    assert(0);
+    puts("here");
+    return EXIT_SUCCESS;
+}

userland/c/getchar.c

@@ -1 +0,0 @@
-../../lkmc/c/getchar.c

userland/c/getchar.c

@@ -0,0 +1,21 @@
+/* Get on character from stdin, and then print it back out.
+ *
+ * Same as getc(stdin).
+ *
+ * You have to press enter for the character to go through:
+ * https://stackoverflow.com/questions/1798511/how-to-avoid-pressing-enter-with-getchar
+ *
+ * Used at:
+ * https://stackoverflow.com/questions/556405/what-do-real-user-and-sys-mean-in-the-output-of-time1/53937376#53937376
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+int main(void) {
+    char c;
+    printf("enter a character: ");
+    c = getchar();
+    printf("you entered: %c\n", c);
+    return EXIT_SUCCESS;
+}

userland/c/hello.c

@@ -1 +0,0 @@
-../../lkmc/c/hello.c

userland/c/hello.c

@@ -0,0 +1,9 @@
+/* Print hello to stdout ;-) */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+int main(void) {
+    puts("hello");
+    return EXIT_SUCCESS;
+}

userland/c/infinite_loop.c

@@ -1 +0,0 @@
-../../lkmc/c/infinite_loop.c

userland/c/infinite_loop.c

@@ -0,0 +1,29 @@
+/* Loop infinitely. Print an integer whenever a period is reached:
+ *
+ * ....
+ * ./infinite_loop [period]
+ * ....
+ */
+
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+int main(int argc, char **argv) {
+    uintmax_t i, j, period;
+    if (argc > 1) {
+        period = strtoumax(argv[1], NULL, 10);
+    } else {
+        period = 100000000;
+    }
+    i = 0;
+    j = 0;
+    while (1) {
+        i++;
+        if (i % period == 0) {
+            printf("%ju\n", j);
+            j++;
+        }
+    }
+}

userland/c/stderr.c

@@ -1 +0,0 @@
-../../lkmc/c/stderr.c

userland/c/stderr.c

@@ -0,0 +1,7 @@
+/* Print hello to stderr. */
+
+#include <stdio.h>
+
+int main(void) {
+    fputs("hello\n", stderr);
+}