1 files changed, 23 insertions, 2 deletions

diff --git a/rsnix/src/fat.rs b/rsnix/src/fat.rs
index 70fa688..616a08f 100644
--- a/rsnix/src/fat.rs
+++ b/rsnix/src/fat.rs
@@ -838,9 +838,30 @@ pub fn remove(parent_dir_cluster: u32, name: &str) -> Result<(), ()> {
 
 // --- mount -------------------------------------------------------------------
 
-/// Parse the BPB, cache the FAT and validate the volume.  Returns true if
-/// a usable FAT32 volume is mounted.
+/// Try to mount a FAT32 volume on every attached disk, in port order, and
+/// keep the first one that validates.  Returns true if a usable FAT32
+/// volume is mounted.
 pub fn init() -> bool {
+    let disks = crate::ahci::disk_count();
+    if disks == 0 {
+        crate::serial_println!("fat: no disk");
+        return false;
+    }
+    for d in 0..disks {
+        if !crate::ahci::select(d) {
+            continue;
+        }
+        if try_mount() {
+            return true;
+        }
+        crate::serial_println!("fat: no FAT32 volume on disk {}", d);
+    }
+    false
+}
+
+/// Parse the BPB of the selected disk, cache the FAT and validate the
+/// volume.
+fn try_mount() -> bool {
     let mut bpb = [0u8; SECTOR];
     if read_sector(0, &mut bpb).is_err() {
         crate::serial_println!("fat: no disk");