1 files changed, 26 insertions, 11 deletions

diff --git a/rsnix/src/memory.rs b/rsnix/src/memory.rs
index a947c53..605125a 100644
--- a/rsnix/src/memory.rs
+++ b/rsnix/src/memory.rs
@@ -366,18 +366,33 @@ fn init_heap() {
             if d.kind == MEMORY_TYPE_CONVENTIONAL {
                 let s = d.physical_start as usize;
                 let e = s + d.number_of_pages as usize * 4096;
-                // Subtract any overlap with the framebuffer region.
-                let (cs, ce) = match fb {
-                    Some((b, sz)) if e > b && s < b + sz => (s.max(b), e.min(b + sz)),
-                    _ => (e, s), // no overlap → empty range
-                };
-                let mut sz = e - s;
-                if ce > cs {
-                    sz -= ce - cs;
+                // Split at the framebuffer hole so the free list NEVER
+                // contains fb pages: a coarse size subtraction leaves one
+                // block *spanning* the hole, letting a large allocation
+                // (e.g. the 1.9 MB display shadow) straddle the display.
+                let mut lo = s;
+                if let Some((b, sz)) = fb
+                    && e > b
+                    && s < b + sz
+                {
+                    let h0 = b.max(s);
+                    let h1 = (b + sz).min(e);
+                    if h0 > lo {
+                        // Segment before the hole.
+                        let seg = h0 - lo;
+                        if seg > best_size {
+                            best_start = lo;
+                            best_size = seg;
+                        }
+                    }
+                    lo = h1;
                 }
-                if sz > best_size {
-                    best_start = s;
-                    best_size = sz;
+                if e > lo {
+                    let seg = e - lo;
+                    if seg > best_size {
+                        best_start = lo;
+                        best_size = seg;
+                    }
                 }
             }
         }