build: add real version numbering

CMakeLists.txt

@@ -16,6 +16,21 @@ set(generic_src_dirs ds init kernel libc sched util vm syscall)
 set(kernel_sources "")
 set(kernel_headers "")
 
+set(version_args --arch ${CMAKE_SYSTEM_PROCESSOR})
+
+if (CMAKE_BUILD_TYPE AND NOT "${CMAKE_BUILD_TYPE}" STREQUAL "Debug")
+	set(version_args ${version_args} "--release")
+endif()
+
+execute_process(
+	COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/tools/magenta.buildid
+		${version_args}
+	OUTPUT_VARIABLE kernel_version
+	WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
+	OUTPUT_STRIP_TRAILING_WHITESPACE)
+
+message(STATUS "Magenta kernel version: ${kernel_version}")
+
 foreach (dir ${generic_src_dirs})
 	file(GLOB_RECURSE dir_sources ${dir}/*.c)
 	file(GLOB_RECURSE dir_headers ${dir}/*.h)
@@ -52,7 +67,7 @@ add_custom_command(
 	COMMAND ${CMAKE_STRIP} -g $<TARGET_FILE:${kernel_exe_name}>)
 
 target_link_libraries(${kernel_exe_name} -nostdlib -ffreestanding -lgcc)
-target_compile_definitions(${kernel_exe_name} PRIVATE BUILD_ID="0")
+target_compile_definitions(${kernel_exe_name} PRIVATE KERNEL_VERSION="${kernel_version}")
 
 include(arch/${kernel_arch}/config.cmake)
 include(arch/${kernel_arch}/targets.cmake)

arch/x86_64/init.c

@@ -92,8 +92,6 @@ static void find_bsp(multiboot_info_t *mb, struct boot_module *out)
 {
 	memset(out, 0x0, sizeof *out);
 
-	printk("modules=%u: %llx", mb->mods_count, mb->mods_addr);
-
 	multiboot_module_t *mods = PTR32(mb->mods_addr);
 	size_t nr_mods = mb->mods_count;
 

init/main.c

@@ -23,7 +23,7 @@ extern char __pstart[], __pend[];
 
 void print_kernel_banner(void)
 {
-	printk("Magenta kernel version " BUILD_ID);
+	printk("Magenta version " KERNEL_VERSION);
 }
 
 static void hang(void)

kernel/panic.c

@@ -17,7 +17,7 @@ void panic_irq(struct ml_cpu_context *ctx, const char *fmt, ...)
 	va_end(args);
 
 	printk("---[ kernel panic: %s", buf);
-	printk("kernel: " BUILD_ID ", compiler version: " __VERSION__);
+	printk("kernel: " KERNEL_VERSION ", compiler version: " __VERSION__);
 
 	struct task *task = get_current_task();
 	struct thread *thr = get_current_thread();

tools/magenta.buildid

@@ -33,7 +33,7 @@ if is_arg_set('release'):
     build_type = 'release'
 
 current_tag = subprocess.check_output(['git', 'describe', '--tags', '--abbrev=0']).decode('utf-8').strip()
-current_tag = current_tag[1:]
+revision = subprocess.check_output(['git', 'rev-list', '{}..HEAD'.format(current_tag), '--count']).decode('utf-8').strip()
 
-build_id = '{}/{}_{}'.format(current_tag, build_type, arch)
+build_id = '{}~{}/{}_{}'.format(current_tag[1:], revision, build_type, arch)
 print('{}'.format(build_id.upper()))