2 files changed, 55 insertions, 0 deletions

diff --git a/bins/mem/Cargo.toml b/bins/mem/Cargo.toml
new file mode 100644
index 0000000..2306fc7
--- /dev/null
+++ b/bins/mem/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "mem"
+version.workspace = true
+edition.workspace = true
+[lints]
+workspace = true
+[dependencies]
+rsapi = { path = "../../rsapi" }
diff --git a/bins/mem/src/main.rs b/bins/mem/src/main.rs
new file mode 100644
index 0000000..fd99f47
--- /dev/null
+++ b/bins/mem/src/main.rs
@@ -0,0 +1,47 @@
+//! mem — show memory statistics via the exports table.
+
+#![no_std]
+#![no_main]
+
+#[panic_handler]
+fn panic(_info: &core::panic::PanicInfo) -> ! {
+    loop { core::hint::spin_loop(); }
+}
+
+fn put(exports: &rsapi::Exports, buf: &[u8]) {
+    (exports.put_line)(rsapi::Line { ptr: buf.as_ptr(), len: buf.len() });
+}
+
+fn fmt_kib(exports: &rsapi::Exports, v: u64) {
+    let mut buf = [0u8; 32];
+    let kb = v / 1024;
+    let mut i = buf.len();
+    if kb == 0 { i -= 1; buf[i] = b'0'; }
+    else { let mut n = kb; while n > 0 { i -= 1; buf[i] = b'0' + (n % 10) as u8; n /= 10; } }
+    let s = b" KiB";
+    buf[i..i+s.len()].copy_from_slice(s);
+    put(exports, &buf[i..i+s.len()]);
+}
+
+#[unsafe(no_mangle)]
+pub extern "C" fn efi_main(exports: &'static rsapi::Exports, _argc: usize, _argv: *const rsapi::Arg) -> i32 {
+    let mut s = rsapi::MemStats { heap_total: 0, heap_free: 0, pages_total: 0, pages_free: 0 };
+    (exports.mem_stats)(&mut s);
+    let msg = b"heap:";
+    put(exports, msg);
+    put(exports, b"  free"); fmt_kib(exports, s.heap_free);
+    put(exports, b" / total"); fmt_kib(exports, s.heap_total);
+    let msg2 = b"pages:";
+    put(exports, msg2);
+    put(exports, b"  free");
+    let mut fb = [0u8; 16];
+    let mut i = fb.len();
+    let n = s.pages_free; if n==0 { i-=1; fb[i]=b'0'; } else { let mut m=n; while m>0 { i-=1; fb[i]=b'0'+(m%10) as u8; m/=10; } }
+    put(exports, &fb[i..]);
+    put(exports, b" / ");
+    let mut tb = [0u8; 16];
+    let mut j = tb.len();
+    let t = s.pages_total; if t==0 { j-=1; tb[j]=b'0'; } else { let mut m=t; while m>0 { j-=1; tb[j]=b'0'+(m%10) as u8; m/=10; } }
+    put(exports, &tb[j..]);
+    0
+}