Factor common userland and baremetal C functions

This allows add.c to run unmodified on both!

For that to work, use int main on baremetal, and pass the return value to
the final exit.

baremetal/add.c

@@ -1,6 +1,6 @@
 #include <common.h>
 
-void main(void) {
+int main(void) {
 	int i, j, k;
 	i = 1;
     /* test-gdb-op1 */
@@ -9,5 +9,5 @@ void main(void) {
 	k = i + j;
     /* test-gdb-result */
 	if (k != 3)
-		assert_fail();
+		common_assert_fail();
 }

baremetal/arch/aarch64/add.S

@@ -7,6 +7,6 @@ main:
     /* test-gdb-result */
     cmp x1, #3
     beq 1f
-    bl assert_fail
+    bl common_assert_fail
 1:
     ret

baremetal/arch/aarch64/fadd.S

@@ -12,7 +12,7 @@ main:
     fmov d3, #4.0
     fcmp d2, d3
     beq 1f
-    bl assert_fail
+    bl common_assert_fail
 1:
 
     /* Now in 32-bit. */
@@ -26,7 +26,7 @@ main:
     fmov s3, #4.0
     fcmp s2, s3
     beq 1f
-    bl assert_fail
+    bl common_assert_fail
 1:
 
     /* Higher registers. */
@@ -40,6 +40,6 @@ main:
     /* test-gdb-d31 */
     fcmp d30, d31
     beq 1f
-    bl assert_fail
+    bl common_assert_fail
 1:
     ret

baremetal/arch/arm/add.S

@@ -7,6 +7,6 @@ main:
     /* test-gdb-result */
     cmp r1, #3
     beq 1f
-    bl assert_fail
+    bl common_assert_fail
 1:
     bx lr

baremetal/exit.c

@@ -1,7 +1,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 
-void main(void) {
+int main(void) {
 	exit(0);
 }
 

baremetal/interactive/assert_fail.c

@@ -1,6 +1,6 @@
 #include <common.h>
 
-void main(void) {
+int main(void) {
-	assert_fail();
+	common_assert_fail();
 }
 

baremetal/interactive/exit1.c

@@ -1,6 +1,6 @@
 #include <stdio.h>
 #include <stdlib.h>
 
-void main(void) {
+int main(void) {
 	exit(1);
 }

baremetal/interactive/hello.c

@@ -1,5 +1,6 @@
 #include <stdio.h>
 
-void main(void) {
+int main(void) {
 	puts("hello");
+	return 0;
 }

baremetal/interactive/prompt.c

@@ -1,7 +1,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 
-void main(void) {
+int main(void) {
     char c;
     char *ptr = NULL;
     size_t alloc_size = 1;
@@ -19,4 +19,3 @@ void main(void) {
         }
     }
 }
-

baremetal/interactive/return1.c

@@ -0,0 +1 @@
+int main(void) { return 1; }

baremetal/lib/aarch64.S

@@ -8,5 +8,4 @@ mystart:
     ldr x0, =stack_top
     mov sp, x0
     bl main
-    mov x0, #0
     bl exit

baremetal/lib/arm.S

@@ -2,5 +2,4 @@
 mystart:
     ldr sp, =stack_top
     bl main
-    mov r0, #0
     bl exit

baremetal/lib/common.h

@@ -1,4 +0,0 @@
-#ifndef COMMON_H
-#define COMMON_H
-void assert_fail();
-#endif

baremetal/lib/syscalls.c

@@ -86,8 +86,3 @@ void _exit(int status) {
 #endif
 #endif
 }
-
-void assert_fail() {
-	puts("lkmc_test_fail");
-	exit(1);
-}

baremetal/return.c

@@ -1 +1 @@
-void main(void) {}
+int main(void) { return 0; }

build-baremetal

@@ -9,9 +9,16 @@ class BaremetalComponent(common.Component):
         common.assert_crosstool_ng_supports_arch(args.arch)
         build_dir = self.get_build_dir(args)
         bootloader_obj = os.path.join(common.baremetal_build_lib_dir, 'bootloader{}'.format(common.obj_ext))
-        common_obj = os.path.join(common.baremetal_build_lib_dir, 'common{}'.format(common.obj_ext))
+        common_basename_noext = 'common'
+        common_src = os.path.join(common.root_dir, common_basename_noext + common.c_ext)
+        common_obj = os.path.join(common.baremetal_build_lib_dir, common_basename_noext + common.obj_ext)
+        syscalls_basename_noext = 'syscalls'
+        syscalls_src = os.path.join(common.baremetal_src_lib_dir, syscalls_basename_noext + common.c_ext)
+        syscalls_obj = os.path.join(common.baremetal_build_lib_dir, syscalls_basename_noext + common.obj_ext)
+        common_objs = [common_obj, syscalls_obj]
         cflags = [
             '-I', common.baremetal_src_lib_dir, common.Newline,
+            '-I', common.root_dir, common.Newline,
             '-O0', common.Newline,
             '-ggdb3', common.Newline,
             '-mcpu={}'.format(common.mcpu), common.Newline,
@@ -46,23 +53,27 @@ class BaremetalComponent(common.Component):
                 os.path.join(common.baremetal_src_lib_dir, '{}{}'.format(args.arch, common.asm_ext)), common.Newline,
             ]
         )
-        common.run_cmd(
+        for src, obj in [
-            [gcc,  common.Newline] +
+            (common_src, common_obj),
-            cflags +
+            (syscalls_src, syscalls_obj),
-            [
+        ]:
-                '-c', common.Newline,
+            common.run_cmd(
-                '-D', 'UART0_ADDR={:#x}'.format(uart_address), common.Newline,
+                [gcc,  common.Newline] +
-                '-o', common_obj, common.Newline,
+                cflags +
-                os.path.join(common.baremetal_src_lib_dir, 'common' + common.c_ext), common.Newline,
+                [
-            ]
+                    '-c', common.Newline,
-        )
+                    '-D', 'UART0_ADDR={:#x}'.format(uart_address), common.Newline,
+                    '-o', obj, common.Newline,
+                    src, common.Newline,
+                ]
+            )
         self._build_dir(
             '',
             gcc=gcc,
             cflags=cflags,
             entry_address=entry_address,
             bootloader_obj=bootloader_obj,
-            common_obj=common_obj,
+            common_objs=common_objs,
         )
         self._build_dir(
             'interactive',
@@ -70,7 +81,7 @@ class BaremetalComponent(common.Component):
             cflags=cflags,
             entry_address=entry_address,
             bootloader_obj=bootloader_obj,
-            common_obj=common_obj,
+            common_objs=common_objs,
         )
         arch_dir = os.path.join('arch', args.arch)
         if os.path.isdir(os.path.join(common.baremetal_src_dir, arch_dir)):
@@ -80,7 +91,7 @@ class BaremetalComponent(common.Component):
                 cflags=cflags,
                 entry_address=entry_address,
                 bootloader_obj=bootloader_obj,
-                common_obj=common_obj,
+                common_objs=common_objs,
             )
         arch_dir = os.path.join('arch', args.arch, 'no_bootloader')
         if os.path.isdir(os.path.join(common.baremetal_src_dir, arch_dir)):
@@ -90,7 +101,7 @@ class BaremetalComponent(common.Component):
                 cflags=cflags,
                 entry_address=entry_address,
                 bootloader_obj=bootloader_obj,
-                common_obj=common_obj,
+                common_objs=common_objs,
                 bootloader=False,
             )
 
@@ -107,7 +118,16 @@ Build the baremetal examples with crosstool-NG.
     def get_default_args(self):
         return {'baremetal': 'all'}
 
-    def _build_dir(self, subpath, gcc, cflags, entry_address, bootloader_obj, common_obj, bootloader=True):
+    def _build_dir(
+            self,
+            subpath,
+            gcc,
+            cflags,
+            entry_address,
+            bootloader_obj,
+            common_objs,
+            bootloader=True
+        ):
         """
         Build all .c and .S files in a given subpath of the baremetal source
         directory non recursively.
@@ -144,8 +164,8 @@ Build the baremetal examples with crosstool-NG.
                         '-T', os.path.join(common.baremetal_src_dir, 'link.ld'), common.Newline,
                     ] +
                     bootloader_cmd +
+                    common.add_newlines(common_objs) +
                     [
-                        common_obj, common.Newline,
                         main_obj, common.Newline,
                     ]
                 )

build-userland

@@ -58,6 +58,8 @@ has the OpenBLAS libraries and headers installed.
                 [
                     'make', common.Newline,
                     '-j', str(args.nproc), common.Newline,
+                    'CCFLAGS_SCRIPT={} {}'.format('-I', common.userland_src_dir), common.Newline,
+                    'COMMON_DIR={}'.format(common.root_dir), common.Newline,
                     'CC={}'.format(cc), common.Newline,
                     'CXX={}'.format(cxx), common.Newline,
                     'PKG_CONFIG={}'.format(common.buildroot_pkg_config), common.Newline,

common.c

@@ -0,0 +1,7 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+void common_assert_fail() {
+	puts("lkmc_test_fail");
+	exit(1);
+}

common.h

@@ -0,0 +1,8 @@
+#ifndef COMMON_H
+#define COMMON_H
+
+/* Common baremetal and userland functionality. */
+
+void common_assert_fail();
+
+#endif

userland/Makefile

@@ -1,13 +1,17 @@
 .PHONY: all clean mkdir
 
+CCFLAGS = -ggdb3 -I$(COMMON_DIR) -O0 -Wall -Werror -Wextra -Wno-unused-function $(CCFLAGS_EXTRA) $(CCFLAGS_SCRIPT)
 CFLAGS = -fopenmp -std=c99 $(CCFLAGS) $(CFLAGS_EXTRA)
 CXXFLAGS = -std=c++17 $(CCFLAGS) $(CXXFLAGS_EXTRA)
 # -Wno-unused-function for function definitions on headers,
 #  because we are lazy to make a shared object. TODO.
-CCFLAGS = -ggdb3 -O0 -Wall -Werror -Wextra -Wno-unused-function $(CCFLAGS_EXTRA)
+COMMON_DIR = ..
+COMMON_BASENAME = common
+COMMON_OBJ = $(OUT_DIR)/$(COMMON_BASENAME)$(OBJ_EXT)
 IN_EXT_C = .c
 IN_EXT_CXX = .cpp
 LIBS = -lm
+OBJ_EXT = .o
 OUT_EXT = .out
 OUT_DIR = .
 
@@ -38,14 +42,17 @@ OUTS := $(addprefix $(OUT_DIR)/,$(OUTS))
 
 all: mkdir $(OUTS)
 
-$(OUT_DIR)/%$(OUT_EXT): %$(IN_EXT_C)
+$(COMMON_OBJ): $(COMMON_DIR)/$(COMMON_BASENAME)$(IN_EXT_C)
-	$(CC) $(CFLAGS) -o '$@' '$<' $(LIBS)
+	$(CC) $(CFLAGS) -c -o '$@' '$<' $(LIBS)
 
-$(OUT_DIR)/%$(OUT_EXT): %$(IN_EXT_CXX)
+$(OUT_DIR)/%$(OUT_EXT): %$(IN_EXT_C) $(COMMON_OBJ)
+	$(CC) $(CFLAGS) $(COMMON_OBJ) -o '$@' '$<' $(LIBS)
+
+$(OUT_DIR)/%$(OUT_EXT): %$(IN_EXT_CXX) $(COMMON_OBJ)
 	$(CXX) $(CXXFLAGS) -o '$@' '$<' $(LIBS)
 
 clean:
-	rm -f *'$(OUT_EXT)'
+	rm -f *'$(OBJ_EXT)' *'$(OUT_EXT)'
 
 mkdir:
 	mkdir -p '$(OUT_DIR)'

userland/add.c

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

userland/mmap.c

@@ -10,7 +10,7 @@
 #include <sys/mman.h>
 #include <unistd.h> /* sysconf */
 
-#include "common.h" /* virt_to_phys_user */
+#include "common_userland.h" /* virt_to_phys_user */
 
 enum { BUFFER_SIZE = 4 };
 

userland/openblas_hello.c

@@ -1,7 +1,7 @@
 /* https://github.com/cirosantilli/linux-kernel-module-cheat#blas
  * Adapted from: https://github.com/xianyi/OpenBLAS/wiki/User-Manual/59b62f98e7400270fb03ad1d85fba5b64ebbff2b#call-cblas-interface */
 
-#include "common.h"
+#include "common_userland.h"
 
 #include <assert.h>
 #include <cblas.h>

userland/pagemap_dump.c

@@ -9,7 +9,7 @@
 #include <sys/types.h>
 #include <unistd.h>
 
-#include "common.h" /* pagemap_get_entry */
+#include "common_userland.h" /* pagemap_get_entry */
 
 int main(int argc, char **argv)
 {

userland/virt_to_phys_user.c

@@ -4,7 +4,7 @@
 #include <stdio.h> /* printf */
 #include <stdlib.h> /* EXIT_SUCCESS, EXIT_FAILURE, strtoull */
 
-#include "common.h" /* virt_to_phys_user */
+#include "common_userland.h" /* virt_to_phys_user */
 
 int main(int argc, char **argv)
 {