update t440p script

coreboot-t440p/steps/backup_bios.sh

@@ -0,0 +1,48 @@
+#!/bin/sh
+# Step: Verify BIOS backup integrity
+
+step_backup_bios() {
+  section "Verify BIOS Backups"
+
+  cd "$WORK_DIR" || return 1
+
+  info "Verifying 4MB chip reads match..."
+  if diff 4mb_backup1.bin 4mb_backup2.bin >/dev/null 2>&1; then
+    success "4MB chip reads are identical."
+  else
+    error "4MB chip reads do NOT match!"
+    warn "The chip may not be reading reliably. Re-seat the programmer and try again."
+    return 1
+  fi
+
+  info "Verifying 8MB chip reads match..."
+  if diff 8mb_backup1.bin 8mb_backup2.bin >/dev/null 2>&1; then
+    success "8MB chip reads are identical."
+  else
+    error "8MB chip reads do NOT match!"
+    warn "The chip may not be reading reliably. Re-seat the programmer and try again."
+    return 1
+  fi
+
+  # Validate file sizes
+  _size_4mb=$(wc -c < 4mb_backup1.bin)
+  _size_8mb=$(wc -c < 8mb_backup1.bin)
+  info "4MB chip size: $_size_4mb bytes (expected $SIZE_4MB)"
+  info "8MB chip size: $_size_8mb bytes (expected $SIZE_8MB)"
+
+  if [ "$_size_4mb" -ne "$SIZE_4MB" ]; then
+    warn "4MB chip size mismatch. Expected $SIZE_4MB bytes, got $_size_4mb."
+    if ! prompt_yes_no "Continue anyway?"; then
+      return 1
+    fi
+  fi
+
+  if [ "$_size_8mb" -ne "$SIZE_8MB" ]; then
+    warn "8MB chip size mismatch. Expected $SIZE_8MB bytes, got $_size_8mb."
+    if ! prompt_yes_no "Continue anyway?"; then
+      return 1
+    fi
+  fi
+
+  success "All BIOS backups verified."
+}