const std = @import("std");
const isa = @import("riscv/isa.zig");
const Fdt = @import("Fdt.zig");
const Console = @import("drivers/Console.zig");

const UART_BASE: usize = 0x10000000;

var console: Console = undefined;

fn uart_put(c: u8) void {
    const uart: *volatile u8 = @ptrFromInt(UART_BASE);
    uart.* = c;
}

fn print(s: []const u8) void {
    for (s) |c| {
        uart_put(c);
    }
}

export fn _start() linksection(".text.init") callconv(.naked) noreturn {
    asm volatile (
        \\li sp, 0x88000000
        \\tail kmain
    );
}

export fn kmain(hartid: u64, fdt_ptr: *const anyopaque) callconv(.c) noreturn {
    _ = hartid;

    const fdt = Fdt.parse(fdt_ptr) catch {
        while (true) asm volatile ("wfi");
    };

    console = Console.init(fdt).?;

    console.print("booting hydra...\n", .{});

    while (true) {
        asm volatile ("wfi");
    }
}