Support for C++ runtime

so3/arch/arm32/context.S

@@ -34,7 +34,6 @@
 .global __exec_prologue_user
 
 .globl __get_syscall_args_ext
-.globl __get_syscall_arg
 
 .global __mmu_switch_ttbr0
 .global __exec

so3/arch/arm64/context.S

@@ -31,7 +31,6 @@
 .global __exec_prologue_user
 
 .globl __get_syscall_args_ext
-.globl __get_syscall_arg
 
 .global __mmu_switch
 .global __exec

so3/arch/arm64/exception.S

@@ -495,13 +495,14 @@ __prepare_sig_handler:
 	ldr	x1, [x0, #OFFSET_SYS_SIGNUM]
 	str	x1, [sp, #OFFSET_X0]
 
+	// Set the handler to the PC
 	ldr	x1, [x0, #OFFSET_SYS_SA]
 	ldr	x2, [x1, #OFFSET_SA_HANDLER]
-	str	x2, [sp, #OFFSET_X1]
+	str	x2, [sp, #OFFSET_PC]
 
-	// Set the handler to the PC
+	// Set restorer to LR so the handler return to it.
 	ldr	x2, [x1, #OFFSET_SA_RESTORER]
-	str	x2, [sp, #OFFSET_PC]
+	str	x2, [sp, #OFFSET_LR]
 
 	ret
 

so3/arch/arm64/traps.c

@@ -247,7 +247,7 @@ void trap_handle(cpu_regs_t *regs)
 
 	default:
 		lprintk("### On CPU %d: ESR_Elx_EC(esr): 0x%lx\n", smp_processor_id(), ESR_ELx_EC(esr));
-		trap_handle_error(regs->lr);
+		trap_handle_error(regs->pc);
 		kernel_panic();
 	}
 }

so3/fs/vfs.c

@@ -467,7 +467,7 @@ static int do_write(int fd, const void *buffer, size_t count)
 }
 
 /* Low Level mmap */
-static int do_mmap(int fd, addr_t virt_addr, uint32_t page_count, off_t offset)
+static long do_mmap(int fd, addr_t virt_addr, uint32_t page_count, off_t offset)
 {
 	int gfd;
 	struct file_operations *fops;
@@ -499,7 +499,7 @@ static int do_mmap(int fd, addr_t virt_addr, uint32_t page_count, off_t offset)
 }
 
 /* Low Level mmap - Anonymous case */
-static int do_mmap_anon(int fd, addr_t virt_addr, uint32_t page_count, off_t offset)
+static long do_mmap_anon(int fd, addr_t virt_addr, uint32_t page_count, off_t offset)
 {
 	uint32_t page;
 	pcb_t *pcb;
@@ -526,7 +526,7 @@ static int do_mmap_anon(int fd, addr_t virt_addr, uint32_t page_count, off_t off
 
 	memset((void *) virt_addr, 0, page_count * PAGE_SIZE);
 
-	/* WARNIMG - This is a simple/basic way to set the start virtual address:
+	/* WARNING - This is a simple/basic way to set the start virtual address:
 	             It only increment the start address after each mmap call, no algorithm
 	             to search for available spaces.
 	*/
@@ -1045,15 +1045,18 @@ SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec *, vec, unsigned l
 	int total = 0;
 
 	for (i = 0; i < vlen; i++) {
-		ret = do_write(fd, (const void *) vec[i].iov_base, vec[i].iov_len);
-		if (ret < 0) {
-			break;
-		} else if ((ret >= 0) && (ret < vec[i].iov_len)) {
+		/* Do nothing for empty buffer */
+		if (vec[i].iov_len != 0) {
+			ret = do_write(fd, (const void *) vec[i].iov_base, vec[i].iov_len);
+			if (ret < 0) {
+				break;
+			} else if ((ret >= 0) && (ret < vec[i].iov_len)) {
+				total += ret;
+				break;
+			}
+
 			total += ret;
-			break;
 		}
-
-		total += ret;
 	}
 
 	if (total == 0)

so3/include/thread.h

@@ -138,7 +138,7 @@ tcb_t *user_thread(clone_args_t *args);
 int thread_join(tcb_t *tcb);
 void thread_exit(int exit_status);
 void clean_thread(tcb_t *tcb);
-SYSCALL_DECLARE(thread_yield, void);
+SYSCALL_DECLARE(sched_yield, void);
 
 void *thread_idle(void *dummy);
 

so3/include/vfs.h

@@ -92,7 +92,7 @@
 #define DT_SOCK 12 /* Socket device */
 
 /* mmap flags options  */
-#define MAP_ANONYMOUS 0x10 /* don't use a file */
+#define MAP_ANONYMOUS 0x20 /* don't use a file */
 
 /* Special value for dirfd used to indicate openat
    should use the current working directory. */

so3/kernel/main.c

@@ -98,7 +98,7 @@ void kernel_start(void)
 {
 	lprintk("%s", SO3_BANNER);
 
-	LOG_INFO("Now bootstraping the kernel ...");
+	LOG_INFO("Now bootstraping the kernel ...\n");
 
 	/* Memory manager subsystem initialization */
 	memory_init();

so3/kernel/process.c

@@ -74,10 +74,12 @@ static uint32_t pid_current = 1;
 static pcb_t *root_process = NULL; /* root process */
 
 /* only the following sections are supported */
-#define SUPPORTED_SECTION_COUNT 6
-static const char *supported_section_names[SUPPORTED_SECTION_COUNT] = {
-	".text", ".rodata", ".data", ".sbss", ".bss", ".scommon",
+static const char *supported_section_names[] = {
+	".init",       ".text",	      ".rodata",      ".data",	   ".sbss",
+	".bss",	       ".scommon",    ".fini",	      ".eh_frame", ".gcc_except_table",
+	".init_array", ".fini_array", ".data.rel.ro", ".got",	   ".got.plt",
 };
+#define SUPPORTED_SECTION_COUNT (sizeof(supported_section_names) / sizeof(supported_section_names[0]))
 
 /*
  * Find a process (pcb_t) from its pid.
@@ -446,7 +448,7 @@ addr_t preserve_args_and_env(int argc, char **argv, char **envp)
 	/* Save env strings and count how many there are */
 	saved->envc = 0;
 	if (envp) {
-		do {
+		while (envp[saved->envc]) {
 			str_len = strlen(envp[saved->envc]) + 1;
 
 			/* Ensure the newly copied string will not exceed the buffer size. */
@@ -459,7 +461,9 @@ addr_t preserve_args_and_env(int argc, char **argv, char **envp)
 
 			strcpy(&saved->arg_env[saved->strings_size], envp[saved->envc]);
 			saved->strings_size += str_len;
-		} while (envp[saved->envc++]);
+
+			saved->envc++;
+		}
 	}
 
 	return (addr_t) saved;
@@ -477,11 +481,12 @@ void post_setup_image(args_env_t *args_env, elf_img_info_t *elf_img_info)
 	args_base = (char *) arch_get_args_base();
 
 	/* Save argc as first arguments */
-	*((int *) args_base) = args_env->argc;
+	*((long *) args_base) = args_env->argc;
 
 	/* Get the base address for the array of pointer for args, env and aux */
-	argv_p_base = (char **) (args_base + sizeof(int));
-	env_p_base = (char **) ((addr_t) argv_p_base + args_env->argc * sizeof(char *));
+	argv_p_base = (char **) (args_base + sizeof(long));
+	/* Add one to account for the null termination of env */
+	env_p_base = (char **) ((addr_t) argv_p_base + (args_env->argc + 1) * sizeof(char *));
 	/* Add one to account for the null termination of env */
 	aux_elf = (elf_addr_t *) ((addr_t) env_p_base + (args_env->envc + 1) * sizeof(char *));
 

so3/kernel/syscalls.c

@@ -31,8 +31,7 @@
 #include <futex.h>
 #include <syscall.h>
 
-extern void __get_syscall_args_ext(uint32_t *syscall_no);
-extern uint32_t __get_syscall_stack_arg(uint32_t nr);
+extern void __get_syscall_args_ext(long *syscall_no);
 
 extern void test_malloc(int test_no);
 
@@ -49,7 +48,7 @@ static const syscall_fn_t syscall_table[NR_SYSCALLS] = {
 
 long syscall_handle(syscall_args_t *syscall_args)
 {
-	uint32_t syscall_no;
+	long syscall_no;
 
 	/* Get addtional args of the syscall according to the ARM & SO3 ABI */
 	__get_syscall_args_ext(&syscall_no);

so3/kernel/thread.c

@@ -339,7 +339,7 @@ void *thread_idle(void *dummy)
 /*
  * Yield to another thread, i.e. simply invoke a call to schedule()
  */
-SYSCALL_DEFINE0(thread_yield)
+SYSCALL_DEFINE0(sched_yield)
 {
 	schedule();
 	return 0;

so3/kernel/timer.c

@@ -436,8 +436,8 @@ SYSCALL_DEFINE2(gettimeofday, struct timeval *, ts, void *, tz)
 
 	time = NOW();
 
-	ts->tv_sec = time / (time_t) 1000000000;
-	ts->tv_usec = time / (time_t) 1000;
+	ts->tv_sec = time / SECONDS(1);
+	ts->tv_usec = (time % SECONDS(1)) / MICROSECS(1);
 
 	return 0;
 }
@@ -475,8 +475,8 @@ SYSCALL_DEFINE2(clock_gettime, int, clk_id, struct timespec *, ts)
 
 	time = NOW();
 
-	ts->tv_sec = time / (time_t) 1000000000;
-	ts->tv_nsec = time;
+	ts->tv_sec = time / SECONDS(1);
+	ts->tv_nsec = time % SECONDS(1);
 
 	return 0;
 }

so3/syscall.tbl

@@ -38,10 +38,11 @@ mmap
 mmap2
 nanosleep
 futex
+sched_yield
 pipe                    IPC_PIPE
 pipe2                   IPC_PIPE
 rt_sigaction            IPC_SIGNAL
-rt_kill                 IPC_SIGNAL
+kill                    IPC_SIGNAL
 sigreturn               IPC_SIGNAL
 rt_sigreturn            IPC_SIGNAL
 rt_sigprocmask          IPC_SIGNAL

usr/CMakeLists.txt

@@ -4,7 +4,7 @@
 
 cmake_minimum_required(VERSION 3.16)
 
-project(so3-usr LANGUAGES C ASM)
+project(so3-usr LANGUAGES C CXX ASM)
 
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 

usr/aarch64-linux-musl.cmake

@@ -26,4 +26,4 @@ set(CMAKE_ASM_FLAGS "-D__ARM64__ -D__ASSEMBLY__")
 
 set(CMAKE_LINKER "aarch64-linux-musl-ld")
 
-set(CMAKE_EXE_LINKER_FLAGS "-Os -static" CACHE STRING "SO3 usr LDFLAGS for executables")
+set(CMAKE_EXE_LINKER_FLAGS "-Os -static -fno-rtti" CACHE STRING "SO3 usr LDFLAGS for executables")

usr/arm-linux-musl.cmake

@@ -26,5 +26,4 @@ set(CMAKE_ASM_FLAGS "-D__ARM__ -D__ASSEMBLY__")
 
 set(CMAKE_LINKER "arm-linux-musleabihf-ld")
 
-
-set(CMAKE_EXE_LINKER_FLAGS "-Os -static" CACHE STRING "SO3 usr LDFLAGS for executables")
+set(CMAKE_EXE_LINKER_FLAGS "-Os -static -fno-rtti" CACHE STRING "SO3 usr LDFLAGS for executables")

usr/build.sh

@@ -11,6 +11,33 @@ usage() {
   echo "  -h        Print this help"
 }
 
+# Place the debug info of the applications in a separate file
+strip_debug_info()
+{
+  # retrieve the correct objcop tool
+  # if [ "$1" == "virt32" -o "$1" == "rpi4" ]; then
+  if [ "$1" = "virt32" ] || [ "$1" = "rpi4" ]; then
+    OBJCOPY="arm-linux-musleabihf-objcopy"
+  else
+    OBJCOPY="aarch64-linux-musl-objcopy"
+  fi
+
+  for app in build/deploy/*.elf; do
+    [ -e "$app" ] || continue
+
+    # 1. Create a file with only '.debug_*' sections
+    $OBJCOPY --only-keep-debug $app $app.debug
+
+    # 2. remove/strip debug info
+    $OBJCOPY --strip-all $app
+
+    # 3. Connect the two files
+    $OBJCOPY --add-gnu-debuglink=$app.debug $app
+
+  done
+}
+
+
 install_file_elf() {
   if [ -f $1 ] ; then 
     for subfolder_app in $(find build/src -type f -iname "*.elf"); do
@@ -120,4 +147,7 @@ install_directory_root out
 
 install_file_elf
 
+strip_debug_info "$PLATFORM"
+
+
 exit 0

usr/deploy.sh

@@ -18,6 +18,6 @@ echo Deploying user apps into the ramfs partition
 cd ../rootfs
 ./mount.sh  ${PLATFORM}
 sudo cp -r ../usr/out/* fs
-sudo cp -r ../usr/build/deploy/* fs
+sudo cp -r ../usr/build/deploy/*.elf fs
 ./umount.sh  ${PLATFORM}
 

usr/src/CMakeLists.txt

@@ -28,3 +28,8 @@ if (MICROPYTHON AND (${CMAKE_SYSTEM_PROCESSOR} STREQUAL "aarch64"))
 	add_subdirectory(micropython)
 endif()
 
+option(WITH_TESTS "Build the test/example apps" ON)
+if (WITH_TESTS)
+    add_subdirectory(tests)
+endif()
+

usr/src/tests/CMakeLists.txt

@@ -0,0 +1,7 @@
+cmake_minimum_required(VERSION 3.16)
+
+add_executable(hello-world.elf hello_world.cpp)
+add_executable(class-test.elf class_test.cpp)
+add_executable(stdlib-test.elf stdlib_test.cpp)
+add_executable(exception-test.elf exception_test.cpp)
+add_executable(allocation-test.elf allocation_test.cpp)

usr/src/tests/allocation_test.cpp

@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2025 Jean-Pierre Miceli <jean-pierre.miceli@heig-vd.ch>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#include <new>
+#include <iostream>
+
+struct Aligned {
+	alignas(64) int x;
+};
+
+int main()
+{
+	void *p = ::operator new(1024);
+	::operator delete(p);
+
+	Aligned *a = new Aligned;
+	delete a;
+
+	std::cout << "Test OK" << std::endl;
+}