pub const arch = @import("arch.zig");
pub const syscall = @import("syscall.zig");
pub const log = @import("log.zig");
const abi = @import("abi");

const Handle = abi.Handle;

fn debug_write(handle: Handle, message: []const u8) void {
    _ = syscall.send(handle, &.{
        @intFromPtr(message.ptr),
        message.len,
        0,
        0,
        0,
    });
}

fn exit_process(handle: Handle, code: u32) noreturn {
    _ = syscall.send(handle, &.{
        @intFromEnum(abi.ProcessObjectAction.ZO_process_exit),
        code,
        0,
        0,
        0,
    });
    unreachable;
}

fn allocate_memory(handle: Handle, count: usize) u64 {
    var output: [5]usize = undefined;
    // TODO error code
    _ = syscall.sendrecv(
        handle,
        &.{
            @intFromEnum(abi.PhysicalMemoryObjectAction.ZO_physical_memory_allocate),
            count,
            0,
            0,
            0,
        },
        &output,
    );
    return output[0];
}

export fn _start(arg: usize) linksection(".text.entry") callconv(.C) noreturn {
    // TODO make the kernel provide those dynamically somehow
    const SELF_PROCESS_HANDLE: Handle = @enumFromInt(1);
    const PHYSICAL_MEMORY_HANDLE: Handle = @enumFromInt(2);
    const DEBUG_HANDLE: Handle = @enumFromInt(3);

    _ = arg;
    const mem = allocate_memory(PHYSICAL_MEMORY_HANDLE, 8);
    _ = mem;

    debug_write(DEBUG_HANDLE, "Hello!!!");
    exit_process(SELF_PROCESS_HANDLE, 4321);
}