homepage/content/projects/noxos/docs/sysabi.md

title	summary	date
Sysabi	The noxos `Application Binary Interface`.	2023-03-14T21:00:40+01:00

Syscalls

Syscalls are a way for programms to communicate with the kernel.

To perform a syscall, you need to populate the following registers:

Register	Value
rax	The syscalls ID
rdi	Argument 1
rsi	Argument 2
rbx	Argument 3
rcx	Argument 4

The following calls should be included to some degree in NoxOS 1.0.

Categories

Files

ID	Name	Description	Arg1	Arg2	Arg3	Arg4	Result	Status
0x0101	nx_fopen		path	len			fd	N/A
0x0102	nx_fclose		fd				success	N/A
0x0103	nx_fread		fd	offset	mem	n	num_bytes	N/A
0x0104	nx_fwrite		fd	offset	mem	n	num_bytes	N/A
0x0105	nx_fdelete		fd				success	N/A
0x0106	nx_flist		fd	mem			needed_mem	N/A
0x0107	nx_finfo		fd	attr	mem		len	N/A

Memory

Category	ID	Name	Description	Arg1	Arg2	Arg3	Arg4	Result	Status

Processes

Category	ID	Name	Description	Arg1	Arg2	Arg3	Arg4	Result	Status

Runtime / Dynamic Linker

Category	ID	Name	Description	Arg1	Arg2	Arg3	Arg4	Result	Status

Compatibility & Safety

Category	ID	Name	Description	Arg1	Arg2	Arg3	Arg4	Result	Status

Kernel

The kernel syscalls can only be called from the kernels main process [link to processing article needed]. If another process calls them, they will just return without doing anything.

Category	ID	Name	Description	Arg1	Arg2	Arg3	Arg4	Result	Status