host kernel module works

.gitignore

@@ -21,3 +21,13 @@ __pycache__
 /m5out
 *.o
 *.out
+
+# Kernel modules.
+.cache.mk
+*.ko.cmd
+*.o.cmd
+.tmp_versions
+Module.symvers
+*.ko
+*.mod.c
+modules.order

README.adoc

@@ -701,7 +701,7 @@ mv broken.c broken.c~
 Once you manage to compile, and have come to terms with the fact that this may blow up your host, try it out with:
 
 ....
-cd "$(./getvar kernel_modules_build_host_dir)"
+cd "$(./getvar kernel_modules_build_host_subdir)"
 sudo insmod hello.ko
 
 # Our module is there.
@@ -726,9 +726,9 @@ Minimal host build system example:
 ....
 cd hello_host_kernel_module
 make
-insmod hello.ko
+sudo insmod hello.ko
 dmesg
-rmmod hello.ko
+sudo rmmod hello.ko
 dmesg
 ....
 
@@ -861,17 +861,6 @@ echo "$(./getvar --arch arm --baremetal prompt --gem5 --machine RealViewPBX
 
 But just stick to newer and better `VExpress_GEM5_V1` unless you have a good reason to use `RealViewPBX`.
 
-This patch is required only for baremetal because the Linux bootloader enters 32 bit mode and switches to 64 for us, but the in the baremetal system we use our own bootloader.
-
-Therefore we must tell gem5 to start the system in aarch64 mode for us with the options:
-
-....
-highest_el_is_64 = True
-auto_reset_addr_64 = True
-....
-
-That patch breaks `--arch arm`, so don't forget to remove it if you want to go back to it.
-
 When doing bare metal programming, it is likely that you will want to learn assembly language basics. Have a look at these tutorials for the userland part:
 
 * https://github.com/cirosantilli/x86-assembly-cheat

build-modules

@@ -3,6 +3,7 @@
 import distutils.dir_util
 import os
 import platform
+import shlex
 import shutil
 
 import common
@@ -10,9 +11,8 @@ import common
 class ModulesComponent(common.Component):
     def add_parser_arguments(self, parser):
         parser.add_argument(
-            'extra_make_args',
-            default=[],
-            metavar='extra-make-args',
+            '--make-args',
+            default='',
             nargs='*'
         )
         parser.add_argument(
@@ -65,8 +65,10 @@ class ModulesComponent(common.Component):
         tool = 'gcc'
         if args.host:
             allowed_toolchains = ['host']
+            build_subdir = common.kernel_modules_build_host_subdir
         else:
             allowed_toolchains = None
+            build_subdir = common.kernel_modules_build_subdir
         gcc = common.get_toolchain_tool(tool, allowed_toolchains=allowed_toolchains)
         prefix = gcc[:-len(tool)]
         ccache = shutil.which('ccache')
@@ -91,18 +93,20 @@ class ModulesComponent(common.Component):
                     'CC={}'.format(cc),
                     'CROSS_COMPILE={}'.format(prefix),
                     'LINUX_DIR={}'.format(linux_dir),
-                    'M={}'.format(common.kernel_modules_build_subdir),
+                    'M={}'.format(build_subdir),
                     'OBJECT_FILES={}'.format(' '.join(object_files)),
                 ] +
+                shlex.split(args.make_args) +
                 verbose
             ),
-            cwd=os.path.join(build_subdir),
-        )
-        common.copy_dir_if_update_non_recursive(
-            srcdir=build_subdir,
-            destdir=common.out_rootfs_overlay_dir,
-            filter_ext=common.kernel_module_ext,
+            cwd=os.path.join(common.kernel_modules_build_subdir),
         )
+        if not args.host:
+            common.copy_dir_if_update_non_recursive(
+                srcdir=common.kernel_modules_build_subdir,
+                destdir=common.out_rootfs_overlay_dir,
+                filter_ext=common.kernel_module_ext,
+            )
 
     def get_argparse_args(self):
         return {

common.py

@@ -804,6 +804,7 @@ def setup(parser):
     this_module.kernel_modules_build_dir = os.path.join(this_module.kernel_modules_build_base_dir, args.arch)
     this_module.kernel_modules_build_subdir = os.path.join(this_module.kernel_modules_build_dir, kernel_modules_subdir)
     this_module.kernel_modules_build_host_dir = os.path.join(this_module.kernel_modules_build_base_dir, 'host')
+    this_module.kernel_modules_build_host_subdir = os.path.join(this_module.kernel_modules_build_host_dir, kernel_modules_subdir)
     this_module.userland_build_dir = os.path.join(this_module.out_dir, 'userland', args.userland_build_id, args.arch)
     this_module.out_rootfs_overlay_dir = os.path.join(this_module.out_dir, 'rootfs_overlay', args.arch)
     this_module.out_rootfs_overlay_bin_dir = os.path.join(this_module.out_rootfs_overlay_dir, 'bin')