mtgos-kernel/docs/syscalls.md

Syscall list

This list is not complete, but the numbers and the arguments are most likely final

• exit(int)
• void *mmap(void *addr, size_t length, int prot)
• void munmap(void *addr, size_t length)
• void closeHandle(void *handle)
• void *duplicateHandle(void *handle)
• void *createService(char name[16], int maxSessions)
• void *connectToService(char name[16])
• void *replyAndReceive(int * handleEventOut, void ** handles, int handleCount, uint8_t data[256]) - returns a handle if there is a new connection or if a handle has closed the connection
• void *create_shared(void **handle_out, void* addr, size_t length, int prot, void *tgt_process) - returns a handle for the other process to map shared memory
• void *mmap_shared(void* handle, void* addr)
• int fork()
• int vfork() - Used for threading
• int getpid()
• int getppid()
• int setppid()

Example code

Bare-metal (no libc) hello world

int main() {
    auto tty_handle = connectToService("tty:u");
    if(!tty_handle)
        exit(1);
    union {
        struct {
            int cmd_id;
            char text[252];
        }__attribute__((packed))
        uint8_t data[256];
    } cmdbuf;
    cmdbuf.cmd_id = 1; //1 == puts()
    const char* s = "Hello, World!";
    int i;
    for(i=0;s[i];i++)
        cmdbuf.text[i]=s[i];
    cmdbuf.text[i]=0;
    replyAndReceive(nullptr, &tty_handle, 1, cmdbuf.data); //Passing nullptr to handleEventOut will not wrote a event handle number
    closeHandle(tty_handle);
    exit(1);
}