syscall: Convert VFS hook /process/create => launch(bytes: [*]align(@alignOf(std.elf.Elf64_Ehdr)) const u8, len: usize) !usize (#60)

1 files changed, 16 insertions, 0 deletions

diff --git a/src/lib/syscall.zig b/src/lib/syscall.zig
index 0767fbd..9841675 100644
--- a/src/lib/syscall.zig
+++ b/src/lib/syscall.zig
@@ -5,6 +5,7 @@
 const std = @import("std");
 
 const instructions = @import("instructions.zig");
+const mem = @import("mem.zig");
 const paging = @import("paging.zig");
 const process = @import("process.zig");
 const sysexchange = @import("sysexchange.zig");
@@ -37,6 +38,7 @@ pub fn handler(proc: *process.Info, trap_frame: *trap.Frame) !void {
         100012 => ret(null, trap_frame, terminate(proc)),
         100013 => ret(null, trap_frame, processId(proc)),
         100014 => ret(null, trap_frame, threadId(proc)),
+        100015 => ret(null, trap_frame, launch(trap_frame)),
         else => return HandleError.UnknownSyscall,
     }
 }
@@ -321,3 +323,17 @@ fn processId(proc: *const process.Info) usize {
 fn threadId(proc: *const process.Info) usize {
     return proc.thread_id;
 }
+
+// launch(bytes: [*]align(@alignOf(std.elf.Elf64_Ehdr)) const u8, len: usize) !usize
+fn launch(trap_frame: *const trap.Frame) !usize {
+    const alignment = @alignOf(std.elf.Elf64_Ehdr);
+    const bytes_addr = trap_frame.general_purpose_registers[10];
+    // fixme: Kernel panic if null pointer
+    const bytes_ptr: [*]align(alignment) const u8 = @ptrFromInt(bytes_addr);
+    const len = trap_frame.general_purpose_registers[11];
+
+    const bytes = bytes_ptr[0..len];
+
+    const new_proc = try process.create(mem.page_allocator, bytes);
+    return new_proc.id;
+}