[kernel] Add process_create syscall

New syscall creates a process (and thus a new virtual address space) but
does not create any threads in it.

src/drivers/nulldrv/main.cpp

@@ -101,11 +101,16 @@ main(int argc, const char **argv)
 	_syscall_system_log(message);
 
 	_syscall_system_log("main thread waiting on child");
-
 	result = _syscall_object_wait(child, -1ull, &out);
 	if (result != j6_status_ok)
 		return result;
 
+	_syscall_system_log("main thread creating a new process");
+	j6_handle_t child_proc = j6_handle_invalid;
+	result = _syscall_process_create(&child_proc);
+	if (result != j6_status_ok)
+		return result;
+
 	_syscall_system_log("main testing irqs");
 
 

src/include/syscalls.inc

@@ -8,7 +8,9 @@ SYSCALL(0x09, object_wait,       j6_handle_t, j6_signal_t, j6_signal_t *)
 SYSCALL(0x0a, object_signal,     j6_handle_t, j6_signal_t)
 SYSCALL(0x0b, object_close,      j6_handle_t)
 
-SYSCALL(0x10, process_exit,      int64_t)
+SYSCALL(0x10, process_create,    j6_handle_t *)
+SYSCALL(0x11, process_start,     j6_handle_t *, uintptr_t)
+SYSCALL(0x17, process_exit,      int64_t)
 
 SYSCALL(0x18, thread_create,     void *, j6_handle_t *)
 SYSCALL(0x19, thread_exit,       int64_t)
@@ -26,6 +28,6 @@ SYSCALL(0x2b, endpoint_sendrecv, j6_handle_t, j6_tag_t *, size_t *, void *)
 
 SYSCALL(0x30, vma_create,        j6_handle_t *, size_t, uint32_t)
 SYSCALL(0x31, vma_create_map,    j6_handle_t *, size_t, uintptr_t, uint32_t)
-SYSCALL(0x32, vma_map,           j6_handle_t, uintptr_t)
+SYSCALL(0x32, vma_map,           j6_handle_t, j6_handle_t, uintptr_t)
-SYSCALL(0x33, vma_unmap,         j6_handle_t)
+SYSCALL(0x33, vma_unmap,         j6_handle_t, j6_handle_t)
 SYSCALL(0x34, vma_resize,        j6_handle_t, size_t *)

src/kernel/syscalls/process.cpp

@@ -3,9 +3,24 @@
 
 #include "log.h"
 #include "objects/process.h"
+#include "syscalls/helpers.h"
 
 namespace syscalls {
 
+j6_status_t
+process_create(j6_handle_t *handle)
+{
+	process *child = construct_handle<process>(handle);
+	log::debug(logs::syscall, "Process %llx created", child->koid());
+	return j6_status_ok;
+}
+
+j6_status_t
+process_start(j6_handle_t *handle, uintptr_t entrypoint)
+{
+	return j6_err_nyi;
+}
+
 j6_status_t
 process_exit(int64_t status)
 {

src/kernel/syscalls/vm_area.cpp

@@ -28,22 +28,28 @@ vma_create_map(j6_handle_t *handle, size_t size, uintptr_t base, uint32_t flags)
 }
 
 j6_status_t
-vma_map(j6_handle_t handle, uintptr_t base)
+vma_map(j6_handle_t handle, j6_handle_t proc, uintptr_t base)
 {
 	vm_area *a = get_handle<vm_area>(handle);
 	if (!a) return j6_err_invalid_arg;
 
-	process::current().space().add(base, a);
+	process *p = get_handle<process>(proc);
+	if (!p) return j6_err_invalid_arg;
+
+	p->space().add(base, a);
 	return j6_status_ok;
 }
 
 j6_status_t
-vma_unmap(j6_handle_t handle)
+vma_unmap(j6_handle_t handle, j6_handle_t proc)
 {
 	vm_area *a = get_handle<vm_area>(handle);
 	if (!a) return j6_err_invalid_arg;
 
-	process::current().space().remove(a);
+	process *p = get_handle<process>(proc);
+	if (!p) return j6_err_invalid_arg;
+
+	p->space().remove(a);
 	return j6_status_ok;
 }