License COS under GPLv2

README.md

@@ -42,3 +42,7 @@ chmod +x build.sh
 This will generate a file `image.iso` inside your working directory. Use VMWare or your favourite VM emulator (or put it on a liveCD if you're brave enough) to run and test it out. Or run `qemu.sh` to run it on QEMU.
 
 ![An image of COS saying 'Hello, world!'](images/hello%20world%20with%20cosh.png)
+
+## License
+
+This project is released under the GPLv2 license. To find out more, read [LICENSE](LICENSE).

kernel/include/kclib/ctype.h

@@ -1,3 +1,19 @@
+/*
+ * ctype.h
+ * Copyright (C) 2026  Aditya Kumar
+ *
+ * This program is free software; you can redistribute it and/or modify it under the terms of the
+ * GNU General Public License as published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * 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, see <https://www.gnu.org/licenses/>.
+ */
+
 #pragma once
 
 int isalnum (int c);

kernel/include/kclib/stdio.h

@@ -1,3 +1,19 @@
+/*
+ * stdio.h
+ * Copyright (C) 2026  Aditya Kumar
+ *
+ * This program is free software; you can redistribute it and/or modify it under the terms of the
+ * GNU General Public License as published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * 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, see <https://www.gnu.org/licenses/>.
+ */
+
 #pragma once
 
 #include <stdarg.h>

kernel/include/kclib/string.h

@@ -1,3 +1,19 @@
+/*
+ * string.h
+ * Copyright (C) 2026  Aditya Kumar
+ *
+ * This program is free software; you can redistribute it and/or modify it under the terms of the
+ * GNU General Public License as published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * 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, see <https://www.gnu.org/licenses/>.
+ */
+
 #pragma once
 
 #include <stddef.h>

kernel/include/kernel/acpi/acpi.h

@@ -1,3 +1,19 @@
+/*
+ * acpi.h
+ * Copyright (C) 2026  Aditya Kumar
+ *
+ * This program is free software; you can redistribute it and/or modify it under the terms of the
+ * GNU General Public License as published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * 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, see <https://www.gnu.org/licenses/>.
+ */
+
 #pragma once
 
 #include <stdint.h>

kernel/include/kernel/acpi/acpi_common.h

@@ -1,3 +1,19 @@
+/*
+ * acpi_common.h
+ * Copyright (C) 2026  Aditya Kumar
+ *
+ * This program is free software; you can redistribute it and/or modify it under the terms of the
+ * GNU General Public License as published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * 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, see <https://www.gnu.org/licenses/>.
+ */
+
 #pragma once
 
 #include <stdint.h>

kernel/include/kernel/acpi/fadt.h

@@ -1,3 +1,19 @@
+/*
+ * fadt.h
+ * Copyright (C) 2026  Aditya Kumar
+ *
+ * This program is free software; you can redistribute it and/or modify it under the terms of the
+ * GNU General Public License as published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * 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, see <https://www.gnu.org/licenses/>.
+ */
+
 #pragma once
 
 #include <kernel/acpi/acpi_common.h>

kernel/include/kernel/acpi/madt.h

@@ -1,3 +1,19 @@
+/*
+ * madt.h
+ * Copyright (C) 2026  Aditya Kumar
+ *
+ * This program is free software; you can redistribute it and/or modify it under the terms of the
+ * GNU General Public License as published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * 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, see <https://www.gnu.org/licenses/>.
+ */
+
 #pragma once
 
 #include <kernel/acpi/acpi_common.h>

kernel/include/kernel/acpi/rsdp.h

@@ -1,3 +1,19 @@
+/*
+ * rsdp.h
+ * Copyright (C) 2026  Aditya Kumar
+ *
+ * This program is free software; you can redistribute it and/or modify it under the terms of the
+ * GNU General Public License as published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * 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, see <https://www.gnu.org/licenses/>.
+ */
+
 #pragma once
 
 #include <stdint.h>

kernel/include/kernel/acpi/rsdt.h

@@ -1,3 +1,19 @@
+/*
+ * rsdt.h
+ * Copyright (C) 2026  Aditya Kumar
+ *
+ * This program is free software; you can redistribute it and/or modify it under the terms of the
+ * GNU General Public License as published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * 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, see <https://www.gnu.org/licenses/>.
+ */
+
 #pragma once
 
 void init_rsdt (uint32_t rsdt_base_ptr);

kernel/include/kernel/con/ansi.h

@@ -1,3 +1,19 @@
+/*
+ * ansi.h
+ * Copyright (C) 2026  Aditya Kumar
+ *
+ * This program is free software; you can redistribute it and/or modify it under the terms of the
+ * GNU General Public License as published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * 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, see <https://www.gnu.org/licenses/>.
+ */
+
 #pragma once
 
 #include <kernel/con/con_ds.h>

kernel/include/kernel/con/con.h

@@ -1,3 +1,19 @@
+/*
+ * con.h
+ * Copyright (C) 2026  Aditya Kumar
+ *
+ * This program is free software; you can redistribute it and/or modify it under the terms of the
+ * GNU General Public License as published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * 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, see <https://www.gnu.org/licenses/>.
+ */
+
 #pragma once
 
 #include <kernel/fs/ioctl.h>

kernel/include/kernel/con/con_ds.h

@@ -1,3 +1,19 @@
+/*
+ * con_ds.h
+ * Copyright (C) 2026  Aditya Kumar
+ *
+ * This program is free software; you can redistribute it and/or modify it under the terms of the
+ * GNU General Public License as published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * 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, see <https://www.gnu.org/licenses/>.
+ */
+
 #pragma once
 
 #include <stddef.h>

kernel/include/kernel/elf.h

@@ -1,3 +1,19 @@
+/*
+ * elf.h
+ * Copyright (C) 2026  Aditya Kumar
+ *
+ * This program is free software; you can redistribute it and/or modify it under the terms of the
+ * GNU General Public License as published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * 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, see <https://www.gnu.org/licenses/>.
+ */
+
 #pragma once
 
 #include <kernel/process.h>

kernel/include/kernel/error.h

@@ -1,3 +1,19 @@
+/*
+ * error.h
+ * Copyright (C) 2026  Aditya Kumar
+ *
+ * This program is free software; you can redistribute it and/or modify it under the terms of the
+ * GNU General Public License as published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * 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, see <https://www.gnu.org/licenses/>.
+ */
+
 #pragma once
 
 #define EPERM			1	/* Not owner */

kernel/include/kernel/exec.h

@@ -1,3 +1,19 @@
+/*
+ * exec.h
+ * Copyright (C) 2026  Aditya Kumar
+ *
+ * This program is free software; you can redistribute it and/or modify it under the terms of the
+ * GNU General Public License as published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * 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, see <https://www.gnu.org/licenses/>.
+ */
+
 #pragma once
 
 #include <stdint.h>

kernel/include/kernel/fs/chardev.h

@@ -1,3 +1,19 @@
+/*
+ * chardev.h
+ * Copyright (C) 2026  Aditya Kumar
+ *
+ * This program is free software; you can redistribute it and/or modify it under the terms of the
+ * GNU General Public License as published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * 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, see <https://www.gnu.org/licenses/>.
+ */
+
 #pragma once
 
 #include <kernel/fs/vfs.h>

kernel/include/kernel/fs/cpio.h

@@ -1,3 +1,19 @@
+/*
+ * cpio.h
+ * Copyright (C) 2026  Aditya Kumar
+ *
+ * This program is free software; you can redistribute it and/or modify it under the terms of the
+ * GNU General Public License as published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * 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, see <https://www.gnu.org/licenses/>.
+ */
+
 #pragma once
 
 #include <kernel/fs/vfs.h>

kernel/include/kernel/fs/fcntl.h

@@ -1,3 +1,19 @@
+/*
+ * fcntl.h
+ * Copyright (C) 2026  Aditya Kumar
+ *
+ * This program is free software; you can redistribute it and/or modify it under the terms of the
+ * GNU General Public License as published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * 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, see <https://www.gnu.org/licenses/>.
+ */
+
 #pragma once
 
 // Flags for fctnl

kernel/include/kernel/fs/ioctl.h

@@ -1,3 +1,19 @@
+/*
+ * ioctl.h
+ * Copyright (C) 2026  Aditya Kumar
+ *
+ * This program is free software; you can redistribute it and/or modify it under the terms of the
+ * GNU General Public License as published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * 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, see <https://www.gnu.org/licenses/>.
+ */
+
 #pragma once
 
 #define TIOCGWINSZ 0x5413