dhrystone baremetal!!!

Factor out --optimization-level and --static to all builds More conventionally set argv[0] to be the basename of the image. Fix https://github.com/cirosantilli/linux-kernel-module-cheat/issues/90
2026-01-22 17:55:57 +01:00 · 2020-04-02 03:00:02 +00:00
parent b7887ac06b
commit 66473201eb
9 changed files with 136 additions and 100 deletions
--- a/README.adoc
+++ b/README.adoc
@@ -16449,13 +16449,22 @@ Run natively on the host:
 "$(./getvar --host userland_build_dir)/submodules/dhrystone/dhrystone"
 ....

-Build for <<baremetal>> execution and run it in baremetal QEMU. TODO: fix the build, just need to factor out all run arguments from link:build-baremetal[] into link:common.py[] and it should just work, no missing syscalls.
+Build Dhrystone for <<baremetal>> and run it in on QEMU:

 ....
 # Build our Newlib stubs.
 ./build-baremetal --arch aarch64
 ./build-dhrystone --arch aarch64 --mode baremetal
-./run --arch aarch64 --baremetal "$(./getvar baremetal_build_dir)/submodules/dhrystone/dhrystone"
+./run --arch aarch64 --baremetal "$(./getvar --arch aarch64 baremetal_build_dir)/submodules/dhrystone/dhrystone" --cli-args 10000
+....
+
+or with gem5:
+
+....
+# Build our Newlib stubs.
+./build-baremetal --arch aarch64
+./build-dhrystone --arch aarch64 --emulator gem5 --mode baremetal
+./run --arch aarch64 --baremetal "$(./getvar --arch aarch64 --emulator gem5 baremetal_build_dir)/submodules/dhrystone/dhrystone" --cli-args 10000 --emulator gem5
 ....

 If you really want the Buildroot package for some reason, build it with:
--- a/baremetal/link.ld
+++ b/baremetal/link.ld
@@ -9,8 +9,13 @@ SECTIONS
    *(.data)
    *(COMMON)
  }
-  /* gem5 uses the bss as a measure of the kernel size. */
+  /* gem5 uses the bss as a measure of the kernel size.
+   * b7887ac06bd7fc8011fbf595b1d50ea67960d28c required __bss_start__
+   * when doing ./build-dhrystone --arch aarch64 --mode baremetal
+   */
+  __bss_start__ = .;
  .bss : { *(.bss) }
+  __bss_end__ = .;
  /* Fix the addresses of everything that comes after, no matter
   * the exact size of the code present in .text. This allows us to
   * place CLI arguments in memory at a known location! */
--- a/42
+++ b/42
@@ -28,33 +28,9 @@ Build the baremetal examples with crosstool-NG.

    def build(self):
        build_dir = self.get_build_dir()
-        extra_obj_baremetal_bootloader = os.path.join(
-            self.env['baremetal_build_lib_dir'],
-            'bootloader{}'.format(self.env['obj_ext'])
-        )
-        extra_obj_lkmc_common = os.path.join(
-            self.env['baremetal_build_lib_dir'],
-            self.env['common_basename_noext'] + self.env['obj_ext']
-        )
        cc_flags = [
            '-I', self.env['root_dir'], LF,
-            '-O{}'.format(self.env['optimization_level']), LF,
-            '-nostartfiles', LF,
        ]
-        if self.env['arch'] == 'arm':
-            cc_flags.extend([
-                '-mhard-float', LF,
-                # This uses the soft float ABI for calling functions from objets in Newlib which
-                # our crosstool-NG config compiles with soft floats, while emiting hard float
-                # from C and allowing us to use it from assembly, e.g. for the VMRS instruction:
-                # which would otherwise fail "with selected processor does not support XXX in ARM mode"
-                # Bibliography:
-                # - https://stackoverflow.com/questions/9753749/arm-compilation-error-vfp-registered-used-by-executable-not-object-file
-                # - https://stackoverflow.com/questions/41131432/cross-compiling-error-selected-processor-does-not-support-fmrx-r3-fpexc-in/41131782#41131782
-                # - https://embeddedartistry.com/blog/2017/10/9/r1q7pksku2q3gww9rpqef0dnskphtc
-                '-mfloat-abi=softfp', LF,
-                '-mfpu=crypto-neon-fp-armv8', LF,
-            ])
        if self.env['emulator'] == 'gem5':
            cc_flags.extend([
                '-DLKMC_GEM5=1', LF,
@@ -63,7 +39,7 @@ Build the baremetal examples with crosstool-NG.
        else:
            cc_flags.extend(['-D', 'LKMC_QEMU=1', LF])
        cc_flags.extend(['-D', 'LKMC_UART0_ADDR={:#x}'.format(self.env['uart_address']), LF])
-        cc_flags.extend(self.sh.shlex_split(self.env['ccflags']))
+        cc_flags.extend(self.env['ccflags'])
        bootloader_src = os.path.join(
            self.env['baremetal_source_lib_dir'],
            '{}{}'.format(
@@ -72,8 +48,8 @@ Build the baremetal examples with crosstool-NG.
            )
        )
        for in_path, out_path in [
-            (bootloader_src, extra_obj_baremetal_bootloader),
-            (self.env['common_c'], extra_obj_lkmc_common),
+            (bootloader_src, self.env['baremetal_extra_obj_bootloader']),
+            (self.env['common_c'], self.env['baremetal_extra_obj_lkmc_common']),
            (
                self.env['baremetal_syscalls_src'],
                self.env['baremetal_syscalls_obj']
@@ -90,11 +66,7 @@ Build the baremetal examples with crosstool-NG.
                extra_deps=[self.env['common_h']],
                link=False,
            )
-        cc_flags.extend([
-            '-Wl,--section-start=.text={:#x}'.format(self.env['entry_address']), LF,
-            # '-Wl,--section-start=.lkmc_memory={:#x}'.format(self.env['entry_address'] + 0x1000000), LF,
-            '-T', self.env['baremetal_link_script'], LF,
-        ])
+        cc_flags.extend(self.env['ldflags'])
        with thread_pool.ThreadPool(
            self._build_one,
            nthreads=self.env['nproc'],
@@ -117,8 +89,8 @@ Build the baremetal examples with crosstool-NG.
                                self.env['baremetal_syscalls_obj'],
                                self.env['baremetal_syscalls_asm_obj']
                            ],
-                            'extra_objs_baremetal_bootloader': [extra_obj_baremetal_bootloader],
-                            'extra_objs_lkmc_common': [extra_obj_lkmc_common],
+                            'extra_objs_baremetal_bootloader': [self.env['baremetal_extra_obj_bootloader']],
+                            'extra_objs_lkmc_common': [self.env['baremetal_extra_obj_lkmc_common']],
                            'in_path': in_path,
                            'out_path': self.resolve_baremetal_executable(in_path),
                        })
@@ -127,7 +99,7 @@ Build the baremetal examples with crosstool-NG.
    def get_build_dir(self):
        return self.env['baremetal_build_dir']

-    def setup_one(self):
+    def setup_one_build(self):
        self.env['targets'] = self.resolve_targets(
            [
                self.env['baremetal_source_dir'],
--- a/15
+++ b/15
@@ -23,27 +23,18 @@ https://cirosantilli.com/linux-kernel-module-cheat#dhrystone

    def build(self):
        build_dir = self.get_build_dir()
-        cflags = ['-O{}'.format(self.env['optimization_level'])]
        extra_flags = []
-        if self.env['static']:
-            cflags.extend(['-static'])
        if self.env['force_rebuild']:
            extra_flags.extend(['-B', LF])
-        if self.env['mode'] == 'baremetal':
-            extra_objs = [
-                self.env['baremetal_syscalls_obj'],
-                self.env['baremetal_syscalls_asm_obj']
-            ]
-        else:
-            extra_objs = []
        ret = self.sh.run_cmd(
            [
                'make', LF,
                '-j', str(self.env['nproc']), LF,
                '-C', os.path.join(self.env['submodules_dir'], 'dhrystone'), LF,
                'CC={}'.format(self.env['gcc_path']), LF,
-                'CFLAGS_EXTRA={}'.format(' '.join(cflags)), LF,
-                'EXTRA_OBJS={}'.format(' '.join(extra_objs)), LF,
+                'CFLAGS_EXTRA={}'.format(self.sh.cmd_to_string(self.env['ccflags'], force_oneline=True)), LF,
+                'LDFLAGS_EXTRA={}'.format(self.sh.cmd_to_string(self.env['ldflags'], force_oneline=True)), LF,
+                'EXTRA_OBJS={}'.format(' '.join(self.env['extra_objs'])), LF,
                'OUT_DIR={}'.format(build_dir), LF,
            ]
            + extra_flags
--- a/7
+++ b/7
@@ -49,10 +49,7 @@ Default: build all examples that have their package dependencies met, e.g.:
        build_dir = self.get_build_dir()
        cc_flags = [
            '-I', self.env['root_dir'], LF,
-            '-O{}'.format(self.env['optimization_level']), LF,
-        ] + self.sh.shlex_split(self.env['ccflags'])
-        if self.env['static']:
-            cc_flags.extend(['-static', LF])
+        ] + self.env['ccflags']
        extra_obj_lkmc_common = os.path.join(
            build_dir,
            self.env['common_basename_noext'] + self.env['obj_ext']
@@ -114,7 +111,7 @@ Default: build all examples that have their package dependencies met, e.g.:
    def get_build_dir(self):
        return self.env['userland_build_dir']

-    def setup_one(self):
+    def setup_one_build(self):
        self.env['targets'] = self.resolve_targets(
            [self.env['userland_source_dir']],
            self.env['targets']
--- a/common.py
+++ b/common.py
@@ -530,7 +530,7 @@ https://cirosantilli.com/linux-kernel-module-cheat#gem5-arm-platforms
            default=True,
            help='''\
 Copy userland build outputs to the overlay directory which will be put inside
-the image. If not given explicitly, this is disabled automatically when certain
+the disk image. If not given explicitly, this is disabled automatically when certain
 options are given, for example --static, since users don't usually want
 static executables to be placed in the final image, but rather only for
 user mode simulations in simulators that don't support dynamic linking like gem5.
@@ -1013,12 +1013,17 @@ Incompatible archs are skipped.
        # Userland
        env['userland_source_arch_arch_dir'] = join(env['userland_source_arch_dir'], env['arch'])
        if env['in_tree']:
-            env['userland_build_dir'] = self.env['userland_source_dir']
+            env['userland_build_dir'] = env['userland_source_dir']
        else:
            env['userland_build_dir'] = join(env['out_dir'], 'userland', env['userland_build_id'], env['arch'])
        env['package'] = set(env['package'])
        if not env['_args_given']['copy_overlay']:
-            if self.env['in_tree'] or self.env['static'] or self.env['host']:
+            if (
+                env['in_tree'] or
+                env['static'] or
+                env['host'] or
+                env['mode'] == 'baremetal'
+            ):
                env['copy_overlay'] = False

        # Kernel modules.
@@ -1048,35 +1053,43 @@ Incompatible archs are skipped.
        env['baremetal_syscalls_basename_noext'] = 'syscalls'
        env['baremetal_syscalls_src'] = os.path.join(
            env['baremetal_source_lib_dir'],
-            env['baremetal_syscalls_basename_noext'] + self.env['c_ext']
+            env['baremetal_syscalls_basename_noext'] + env['c_ext']
        )
        env['baremetal_syscalls_obj'] = os.path.join(
-            self.env['baremetal_build_lib_dir'],
-            env['baremetal_syscalls_basename_noext'] + self.env['obj_ext']
+            env['baremetal_build_lib_dir'],
+            env['baremetal_syscalls_basename_noext'] + env['obj_ext']
        )
        env['baremetal_syscalls_asm_src'] = os.path.join(
-            self.env['baremetal_source_lib_dir'],
-            env['baremetal_syscalls_basename_noext'] + '_asm' + self.env['asm_ext']
+            env['baremetal_source_lib_dir'],
+            env['baremetal_syscalls_basename_noext'] + '_asm' + env['asm_ext']
        )
        env['baremetal_syscalls_asm_obj'] = os.path.join(
-            self.env['baremetal_build_lib_dir'],
-            env['baremetal_syscalls_basename_noext'] + '_asm' + self.env['obj_ext']
+            env['baremetal_build_lib_dir'],
+            env['baremetal_syscalls_basename_noext'] + '_asm' + env['obj_ext']
        )
        if env['emulator'] == 'gem5':
            if env['machine'] == 'VExpress_GEM5_V1':
                env['entry_address'] = 0x80000000
                env['uart_address'] = 0x1c090000
-            elif self.env['machine'] == 'RealViewPBX':
+            elif env['machine'] == 'RealViewPBX':
                env['entry_address'] = 0x10000
                env['uart_address'] = 0x10009000
            else:
-                raise Exception('unknown machine: ' + self.env['machine'])
+                raise Exception('unknown machine: ' + env['machine'])
        else:
            env['entry_address'] = 0x40000000
-            env['uart_address']= 0x09000000
+            env['uart_address'] = 0x09000000
+        env['common_basename_noext'] = env['repo_short_id']
+        env['baremetal_extra_obj_bootloader'] = join(
+            env['baremetal_build_lib_dir'],
+            'bootloader{}'.format(env['obj_ext'])
+        )
+        env['baremetal_extra_obj_lkmc_common'] = join(
+            env['baremetal_build_lib_dir'],
+            env['common_basename_noext'] + env['obj_ext']
+        )

        # Userland / baremetal common source.
-        env['common_basename_noext'] = env['repo_short_id']
        env['common_c'] = os.path.join(
            env['root_dir'],
            env['common_basename_noext'] + env['c_ext']
@@ -1087,8 +1100,38 @@ Incompatible archs are skipped.
        )
        if env['mode'] == 'baremetal':
            env['build_dir'] = env['baremetal_build_dir']
+            env['extra_objs'] = [
+                env['baremetal_extra_obj_bootloader'],
+                env['baremetal_extra_obj_lkmc_common'],
+                env['baremetal_syscalls_asm_obj'],
+                env['baremetal_syscalls_obj'],
+            ]
+            env['ccflags_default'] = [
+                '-nostartfiles', LF,
+            ]
+            if env['arch'] == 'arm':
+                env['ccflags_default'].extend([
+                    '-mhard-float', LF,
+                    # This uses the soft float ABI for calling functions from objets in Newlib which
+                    # our crosstool-NG config compiles with soft floats, while emiting hard float
+                    # from C and allowing us to use it from assembly, e.g. for the VMRS instruction:
+                    # which would otherwise fail "with selected processor does not support XXX in ARM mode"
+                    # Bibliography:
+                    # - https://stackoverflow.com/questions/9753749/arm-compilation-error-vfp-registered-used-by-executable-not-object-file
+                    # - https://stackoverflow.com/questions/41131432/cross-compiling-error-selected-processor-does-not-support-fmrx-r3-fpexc-in/41131782#41131782
+                    # - https://embeddedartistry.com/blog/2017/10/9/r1q7pksku2q3gww9rpqef0dnskphtc
+                    '-mfloat-abi=softfp', LF,
+                    '-mfpu=crypto-neon-fp-armv8', LF,
+                ])
+            env['ldflags'] = [
+                '-Wl,--section-start=.text={:#x}'.format(env['entry_address']), LF,
+                '-T', env['baremetal_link_script'], LF,
+            ]
        else:
            env['build_dir'] = env['userland_build_dir']
+            env['ccflags_default'] = []
+            env['extra_objs'] = []
+            env['ldflags'] = []

        # Docker
        env['docker_build_dir'] = join(env['out_dir'], 'docker', env['arch'])
@@ -1247,25 +1290,6 @@ lunch aosp_{}-eng
                )
            )

-    @staticmethod
-    def python_escape_double_quotes(s):
-        s2 = []
-        for c in s:
-            if c == '"':
-                s2.append('\\"')
-            else:
-                s2.append(c)
-        return ''.join(s2)
-
-    @staticmethod
-    def python_struct_int_format(size):
-        if size == 4:
-            return 'i'
-        elif size ==  8:
-            return 'Q'
-        else:
-            raise 'unknown size {}'.format(size)
-
    def get_elf_entry(self, elf_file_path):
        readelf_header = self.sh.check_output([
            self.get_toolchain_tool('readelf'),
@@ -1449,11 +1473,11 @@ lunch aosp_{}-eng
                        env['_args_given']['emulators'] = True
                        env['all_emulators'] = False
                        self.env = env.copy()
-                        self._init_env(self.env)
                        self.sh = shell_helpers.ShellHelpers(
                            dry_run=self.env['dry_run'],
                            quiet=(not show_cmds),
                        )
+                        self._init_env(self.env)
                        self.setup_one()
                        ret = self.timed_main()
                        if not env['dry_run']:
@@ -1487,6 +1511,25 @@ lunch aosp_{}-eng
        os.makedirs(self.env['p9_dir'], exist_ok=True)
        os.makedirs(self.env['qemu_run_dir'], exist_ok=True)

+    @staticmethod
+    def python_escape_double_quotes(s):
+        s2 = []
+        for c in s:
+            if c == '"':
+                s2.append('\\"')
+            else:
+                s2.append(c)
+        return ''.join(s2)
+
+    @staticmethod
+    def python_struct_int_format(size):
+        if size == 4:
+            return 'i'
+        elif size ==  8:
+            return 'Q'
+        else:
+            raise 'unknown size {}'.format(size)
+
    @staticmethod
    def seconds_to_hms(seconds):
        '''
@@ -1906,6 +1949,24 @@ after configure, e.g. SCons. Usually contains specific targets or other build fl
                return True
        return False

+    def setup_one(self):
+        ccflags = []
+        ccflags.extend(self.env['ccflags_default'])
+        if 'optimization_level' in self.env:
+            ccflags.extend(['-O{}'.format(self.env['optimization_level']), LF])
+        if self.env['static']:
+            ccflags.extend(['-static', LF])
+        if 'ccflags' in self.env:
+            ccflags.extend(self.sh.shlex_split(self.env['ccflags']))
+        self.env['ccflags'] = ccflags
+        self.setup_one_build()
+
+    def setup_one_build(self):
+        '''
+        Called once before every build type, after BuildCliFunction::setup_one
+        '''
+        pass
+
    def timed_main(self):
        '''
        Parse CLI, and to the build based on it.
--- a/13
+++ b/13
@@ -485,23 +485,22 @@ Extra options to append at the end of the emulator command line.
            # argv[1][0] data
            # argv[1][1] data
            # ...
+            cli_args = [os.path.basename(self.env['image'])]
            if self.env['cli_args'] is not None:
-                cli_args_split = shlex.split(self.env['cli_args'])
-            else:
-                cli_args_split = []
+                cli_args.extend(shlex.split(self.env['cli_args']))
            argc_addr = self.env['entry_address'] + self.env['baremetal_max_text_size'] + self.env['baremetal_memory_size']
            argv_addr = argc_addr + self.env['int_size']
-            argv_data_addr = argv_addr + len(cli_args_split) * self.env['address_size']
+            argv_data_addr = argv_addr + len(cli_args) * self.env['address_size']
            argv_addr_data = []
            argv_addr_cur = argv_data_addr
-            for arg in cli_args_split:
+            for arg in cli_args:
                argv_addr_data.append(struct.pack('<{}'.format(self.python_struct_int_format(self.env['address_size'])), argv_addr_cur))
                argv_addr_cur += len(arg) + 1
            baremetal_cli_path = os.path.join(self.env['run_dir'], 'baremetal_cli.raw')
            with open(baremetal_cli_path, 'wb') as f:
-                f.write(struct.pack('<{}'.format(self.python_struct_int_format(self.env['int_size'])), len(cli_args_split)))
+                f.write(struct.pack('<{}'.format(self.python_struct_int_format(self.env['int_size'])), len(cli_args)))
                f.write(b''.join(argv_addr_data))
-                f.write(b'\0'.join(arg.encode() for arg in cli_args_split) + b'\0')
+                f.write(b'\0'.join(arg.encode() for arg in cli_args) + b'\0')
        if self.env['emulator'] == 'gem5':
            if self.env['quiet']:
                show_stdout = False
--- a/submodules/dhrystone
+++ b/submodules/dhrystone
--- a/userland/c/command_line_arguments.c
+++ b/userland/c/command_line_arguments.c
@@ -3,8 +3,10 @@
 #include <stdio.h>

 int main(int argc, char **argv) {
-    size_t i;
-    for (i = 0; i < (size_t)argc; ++i)
-        printf("%s\n", argv[i]);
+    int i;
+    printf("argc = %d\n", argc);
+    for (i = 0; i < argc; ++i) {
+        printf("argv[%d] = %s\n", i, argv[i]);
+    }
    return 0;
 }