2 files changed, 146 insertions, 0 deletions

diff --git a/rsdos/Cargo.toml b/rsdos/Cargo.toml
new file mode 100644
index 0000000..5bf83fe
--- /dev/null
+++ b/rsdos/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "rsdos"
+version.workspace = true
+edition.workspace = true
+
+[dependencies]
+rsnix = { path = "../rsnix" }
+shell = { path = "../shell" }
diff --git a/rsdos/src/main.rs b/rsdos/src/main.rs
new file mode 100644
index 0000000..543556b
--- /dev/null
+++ b/rsdos/src/main.rs
@@ -0,0 +1,138 @@
+#![no_std]
+#![no_main]
+#![allow(static_mut_refs, unsafe_code)]
+
+use core::panic::PanicInfo;
+use rsnix::uefi::*;
+
+// ---------------------------------------------------------------------------
+// Panic handler
+// ---------------------------------------------------------------------------
+#[panic_handler]
+fn panic(info: &PanicInfo) -> ! {
+    use core::fmt::Write;
+    rsnix::serial::write_str("\r\n*** PANIC ***\r\n");
+    let _ = write!(&mut rsnix::serial::SerialWriter, "{}\r\n", info.message());
+    if let Some(loc) = info.location() {
+        let _ = write!(
+            &mut rsnix::serial::SerialWriter,
+            "  at {}:{}\r\n",
+            loc.file(),
+            loc.line()
+        );
+    }
+    loop {
+        unsafe {
+            core::arch::asm!("cli; hlt");
+        }
+    }
+}
+
+// ---------------------------------------------------------------------------
+// EFI entry point
+// ---------------------------------------------------------------------------
+#[no_mangle]
+pub extern "efiapi" fn efi_main(image_handle: Handle, system_table: *mut SystemTable) -> ! {
+    let st = unsafe { &mut *system_table };
+    let bs = unsafe { &mut *st.boot_services };
+    let con_out = unsafe { &mut *st.con_out };
+
+    // ---- Phase 1: UEFI boot services alive ----
+
+    // Print banner via UEFI console
+    unsafe {
+        let s = concat!("rsnix v", env!("CARGO_PKG_VERSION"), " booting..\n");
+        let bytes = s.as_bytes();
+        let mut buf: [u16; 48] = [0; 48];
+        for (i, &b) in bytes.iter().enumerate().take(47) {
+            buf[i] = b as u16;
+        }
+        (con_out.output_string)(con_out, buf.as_ptr());
+    }
+
+    rsnix::serial::init();
+    rsnix::serial_println!("=== rsnix boot ===");
+
+    // Stash the memory map
+    let map_key = match rsnix::memory::capture_memory_map(bs) {
+        Ok(k) => k,
+        Err(e) => {
+            rsnix::serial_println!("mem: capture_memory_map failed 0x{:x}", e);
+            0
+        }
+    };
+
+    // Locate GOP (Graphics Output Protocol)
+    let mut gop_interface: *mut core::ffi::c_void = core::ptr::null_mut();
+    let gop_guid = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
+    let gop_result = unsafe {
+        (bs.locate_protocol)(
+            &gop_guid as *const Guid,
+            core::ptr::null_mut(),
+            &mut gop_interface,
+        )
+    };
+    if gop_result == EFI_SUCCESS {
+        let gop = unsafe { &mut *(gop_interface as *mut GraphicsOutputProtocol) };
+        rsnix::serial_println!("gop: framebuffer found");
+        rsnix::gop::init(gop);
+    } else {
+        rsnix::serial_println!("gop: not found (0x{:x})", gop_result);
+    }
+
+    // ExitBootServices — we now own the machine
+    if unsafe { (bs.exit_boot_services)(image_handle, map_key) } != EFI_SUCCESS {
+        rsnix::serial_println!("WARN: ExitBootServices failed, retrying...");
+        match rsnix::memory::refresh_and_exit(bs, image_handle) {
+            Ok(_) => {}
+            Err(e) => {
+                rsnix::serial_println!("FATAL: cannot ExitBootServices (0x{:x})", e);
+                loop {
+                    unsafe {
+                        core::arch::asm!("cli; hlt");
+                    }
+                }
+            }
+        }
+    }
+
+    // ---- Phase 2: Native mode ----
+    rsnix::serial::init();
+    rsnix::serial_println!("serial: COM1 115200 8N1");
+    rsnix::ps2::init();
+    rsnix::serial_println!("ps2: keyboard initialized");
+    rsnix::interrupts::init();
+    rsnix::serial_println!("intr: IDT loaded, PIC remapped, timer ~100 Hz");
+
+    dump_memory_summary();
+
+    rsnix::serial_println!("boot: entering shell");
+    shell::run();
+}
+
+// ---------------------------------------------------------------------------
+// Print a memory summary from the stashed memory map
+// ---------------------------------------------------------------------------
+fn dump_memory_summary() {
+    let (map, key) = rsnix::memory::get_map();
+    let mut conventional_4k = 0u64;
+    let mut addr_space_4k = 0u64;
+    for desc in map.iter() {
+        let pages = desc.number_of_pages;
+        addr_space_4k += pages;
+        if desc.kind == 7 {
+            conventional_4k += pages;
+        }
+    }
+    rsnix::serial_println!(
+        "mem: {} entries, key=0x{:x}, usable: {} KB ({} MB)",
+        map.len(),
+        key,
+        conventional_4k * 4,
+        (conventional_4k * 4) / 1024,
+    );
+    rsnix::serial_println!(
+        "mem: address space: {} MB (incl. PCIe MMIO)",
+        (addr_space_4k * 4) / 1024,
+    );
+}