initial commit

src/platform/um/entry.zig

@@ -0,0 +1,81 @@
+const b = @import("base");
+
+pub const std_options = b.std_options;
+
+const std = @import("std");
+const ke = b.ke;
+const pl = b.pl;
+
+const default_mem_size = b.gib(1);
+
+fn parse_mem_size(str: []const u8) !usize {
+    if (str.len == 0) return default_mem_size;
+
+    const last = str[str.len - 1];
+
+    const mul: usize = switch (std.ascii.toLower(last)) {
+        'k' => b.kib(1),
+        'm' => b.mib(1),
+        'g' => b.gib(1),
+        else => 1,
+    };
+
+    const digits = if (mul == 1) str else str[0 .. str.len - 1];
+    const size = try std.fmt.parseInt(usize, digits, 10);
+    return size * mul;
+}
+
+pub fn main(init: std.process.Init) !void {
+    var args = try init.minimal.args.iterateAllocator(init.gpa);
+    defer args.deinit();
+
+    const exe = args.next().?;
+
+    var mem_size: usize = default_mem_size;
+    var cmdline: ?[]const u8 = null;
+    var ncpus: usize = 1;
+
+    while (args.next()) |arg| {
+        if (std.mem.eql(u8, arg, "-m") or std.mem.eql(u8, arg, "--mem-size")) {
+            const val = args.next() orelse fatal("--mem-size requires a value", .{});
+            mem_size = parse_mem_size(val) catch fatal("invalid mem-size", .{});
+        } else if (std.mem.eql(u8, arg, "-c") or std.mem.eql(u8, arg, "--cmdline")) {
+            cmdline = args.next() orelse fatal("--cmdline requires a value", .{});
+        } else if (std.mem.eql(u8, arg, "-t") or std.mem.eql(u8, arg, "--threads")) {
+            const val = args.next() orelse fatal("--threads requires a value", .{});
+            ncpus = std.fmt.parseInt(usize, val, 10) catch fatal("invalid thread count", .{});
+        } else if (std.mem.eql(u8, arg, "--help") or std.mem.eql(u8, arg, "-h")) {
+            var stderr = std.Io.File.stderr().writerStreaming(init.io, &.{});
+            var w = &stderr.interface;
+
+            try w.print(
+                \\Usage: {s} [options]
+                \\  -m, --mem-size SIZE    Set the memory size
+                \\  -c, --cmdline STR      Set the kernel cmdline
+                \\  -t, --threads COUNT    Set the number of threads
+                \\
+            , .{exe});
+            std.process.exit(0);
+        } else {
+            fatal("unknown argument: {s}", .{arg});
+        }
+    }
+
+    pl.impl.global_state.params =
+        .{ .ncpus = ncpus, .cmdline = cmdline, .mem_size = mem_size };
+
+    pl.impl.global_state.boot_info.kernel_address.physical_base = 0;
+    pl.impl.global_state.boot_info.kernel_address.virtual_base = 0;
+
+    pl.impl.global_state.boot_info.rsdp = 0;
+    pl.impl.global_state.boot_info.cmdline = cmdline;
+
+    ke.ncpus = ncpus;
+
+    ke.private.init(&pl.impl.global_state.boot_info);
+}
+
+fn fatal(comptime fmt: []const u8, args: anytype) noreturn {
+    std.debug.print(fmt ++ "\n", args);
+    std.process.exit(1);
+}