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|
const std = @import("../index.zig");
const assert = std.debug.assert;
//////////////////////////
//// IPC structures ////
//////////////////////////
pub const Message = struct {
sender: MailboxId,
receiver: MailboxId,
code: usize,
args: [5]usize,
payload: ?[]const u8,
pub fn from(mailbox_id: MailboxId) Message {
return Message{
.sender = MailboxId.Undefined,
.receiver = mailbox_id,
.code = undefined,
.args = undefined,
.payload = null,
};
}
pub fn to(mailbox_id: MailboxId, msg_code: usize, args: ...) Message {
var message = Message{
.sender = MailboxId.This,
.receiver = mailbox_id,
.code = msg_code,
.args = undefined,
.payload = null,
};
assert(args.len <= message.args.len);
comptime var i = 0;
inline while (i < args.len) : (i += 1) {
message.args[i] = args[i];
}
return message;
}
pub fn as(self: Message, sender: MailboxId) Message {
var message = self;
message.sender = sender;
return message;
}
pub fn withPayload(self: Message, payload: []const u8) Message {
var message = self;
message.payload = payload;
return message;
}
};
pub const MailboxId = union(enum) {
Undefined,
This,
Kernel,
Port: u16,
Thread: u16,
};
//////////////////////////////////////
//// Ports reserved for servers ////
//////////////////////////////////////
pub const Server = struct {
pub const Keyboard = MailboxId{ .Port = 0 };
pub const Terminal = MailboxId{ .Port = 1 };
};
////////////////////////
//// POSIX things ////
////////////////////////
// Standard streams.
pub const STDIN_FILENO = 0;
pub const STDOUT_FILENO = 1;
pub const STDERR_FILENO = 2;
// FIXME: let's borrow Linux's error numbers for now.
use @import("linux/errno.zig");
// Get the errno from a syscall return value, or 0 for no error.
pub fn getErrno(r: usize) usize {
const signed_r = @bitCast(isize, r);
return if (signed_r > -4096 and signed_r < 0) @intCast(usize, -signed_r) else 0;
}
// TODO: implement this correctly.
pub fn read(fd: i32, buf: [*]u8, count: usize) usize {
switch (fd) {
STDIN_FILENO => {
var i: usize = 0;
while (i < count) : (i += 1) {
send(&Message.to(Server.Keyboard, 0));
// FIXME: we should be certain that we are receiving from Keyboard.
var message = Message.from(MailboxId.This);
receive(&message);
buf[i] = @intCast(u8, message.args[0]);
}
},
else => unreachable,
}
return count;
}
// TODO: implement this correctly.
pub fn write(fd: i32, buf: [*]const u8, count: usize) usize {
switch (fd) {
STDOUT_FILENO, STDERR_FILENO => {
send(&Message.to(Server.Terminal, 1).withPayload(buf[0..count]));
},
else => unreachable,
}
return count;
}
///////////////////////////
//// Syscall numbers ////
///////////////////////////
pub const Syscall = enum(usize) {
exit = 0,
send = 1,
receive = 2,
subscribeIRQ = 3,
inb = 4,
outb = 5,
map = 6,
createThread = 7,
};
////////////////////
//// Syscalls ////
////////////////////
pub fn exit(status: i32) noreturn {
_ = syscall1(Syscall.exit, @bitCast(usize, isize(status)));
unreachable;
}
pub fn send(message: *const Message) void {
_ = syscall1(Syscall.send, @ptrToInt(message));
}
pub fn receive(destination: *Message) void {
_ = syscall1(Syscall.receive, @ptrToInt(destination));
}
pub fn subscribeIRQ(irq: u8, mailbox_id: *const MailboxId) void {
_ = syscall2(Syscall.subscribeIRQ, irq, @ptrToInt(mailbox_id));
}
pub fn inb(port: u16) u8 {
return @intCast(u8, syscall1(Syscall.inb, port));
}
pub fn outb(port: u16, value: u8) void {
_ = syscall2(Syscall.outb, port, value);
}
pub fn map(v_addr: usize, p_addr: usize, size: usize, writable: bool) bool {
return syscall4(Syscall.map, v_addr, p_addr, size, @boolToInt(writable)) != 0;
}
pub fn createThread(function: fn () void) u16 {
return u16(syscall1(Syscall.createThread, @ptrToInt(function)));
}
/////////////////////////
//// Syscall stubs ////
/////////////////////////
inline fn syscall0(number: Syscall) usize {
return asm volatile ("int $0x80"
: [ret] "={eax}" (-> usize)
: [number] "{eax}" (number)
);
}
inline fn syscall1(number: Syscall, arg1: usize) usize {
return asm volatile ("int $0x80"
: [ret] "={eax}" (-> usize)
: [number] "{eax}" (number),
[arg1] "{ecx}" (arg1)
);
}
inline fn syscall2(number: Syscall, arg1: usize, arg2: usize) usize {
return asm volatile ("int $0x80"
: [ret] "={eax}" (-> usize)
: [number] "{eax}" (number),
[arg1] "{ecx}" (arg1),
[arg2] "{edx}" (arg2)
);
}
inline fn syscall3(number: Syscall, arg1: usize, arg2: usize, arg3: usize) usize {
return asm volatile ("int $0x80"
: [ret] "={eax}" (-> usize)
: [number] "{eax}" (number),
[arg1] "{ecx}" (arg1),
[arg2] "{edx}" (arg2),
[arg3] "{ebx}" (arg3)
);
}
inline fn syscall4(number: Syscall, arg1: usize, arg2: usize, arg3: usize, arg4: usize) usize {
return asm volatile ("int $0x80"
: [ret] "={eax}" (-> usize)
: [number] "{eax}" (number),
[arg1] "{ecx}" (arg1),
[arg2] "{edx}" (arg2),
[arg3] "{ebx}" (arg3),
[arg4] "{esi}" (arg4)
);
}
inline fn syscall5(
number: Syscall,
arg1: usize,
arg2: usize,
arg3: usize,
arg4: usize,
arg5: usize,
) usize {
return asm volatile ("int $0x80"
: [ret] "={eax}" (-> usize)
: [number] "{eax}" (number),
[arg1] "{ecx}" (arg1),
[arg2] "{edx}" (arg2),
[arg3] "{ebx}" (arg3),
[arg4] "{esi}" (arg4),
[arg5] "{edi}" (arg5)
);
}
inline fn syscall6(
number: Syscall,
arg1: usize,
arg2: usize,
arg3: usize,
arg4: usize,
arg5: usize,
arg6: usize,
) usize {
return asm volatile ("int $0x80"
: [ret] "={eax}" (-> usize)
: [number] "{eax}" (number),
[arg1] "{ecx}" (arg1),
[arg2] "{edx}" (arg2),
[arg3] "{ebx}" (arg3),
[arg4] "{esi}" (arg4),
[arg5] "{edi}" (arg5),
[arg6] "{ebp}" (arg6)
);
}
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