diff --git a/spi_check.py b/spi_check.py
new file mode 100755
index 0000000..d0fef97
--- /dev/null
+++ b/spi_check.py
@@ -0,0 +1,73 @@
+#!/usr/bin/env python3
+"""RK3588 SPI image pre-flash integrity check.
+
+Verifies a u-boot-rockchip-spi*.bin image *before* the user commits
+to a maskrom-recovery-prone flash. Catches the class of silent-build
+failures that brick boards:
+
+  - missing idbloader (binman packed 0xFF where RKNS wrapper should be)
+  - truncated idbloader (less than the declared payload region)
+  - mkimage-rejected TPL blob that left the SPL slot empty
+
+Does NOT execute code — pure static parsing. Fast and safe.
+
+Exit codes:
+  0  = image has a valid-looking idbloader; safe to flash
+  1  = file unreadable / too small
+  2  = missing RKNS wrapper at 0x8000 (the "today's bug" case)
+  3  = wrapper present but surrounding region is all 0xFF (payload missing)
+
+Usage: rk3588_spi_check.py <spi-image.bin>
+"""
+import struct
+import sys
+
+IDBL_OFFSET = 0x8000
+RKNS_MAGIC  = 0x534E4B52   # "RKNS" LE — rkspi boot header
+PAYLOAD_END = 0x60000      # stock u-boot places next section here
+
+def die(code, msg):
+    print(f"FAIL: {msg}", file=sys.stderr)
+    sys.exit(code)
+
+def main(path):
+    with open(path, "rb") as f:
+        data = f.read()
+    print(f"SPI image: {path}  size=0x{len(data):x} ({len(data)} B)")
+
+    if len(data) < PAYLOAD_END:
+        die(1, f"image too small ({len(data)} < 0x{PAYLOAD_END:x})")
+
+    wrapper = struct.unpack_from("<I", data, IDBL_OFFSET)[0]
+    if wrapper != RKNS_MAGIC:
+        die(2, f"no RKNS wrapper at 0x{IDBL_OFFSET:x}: got 0x{wrapper:08x} "
+               f"(expect 0x{RKNS_MAGIC:08x}). idbloader was not produced — "
+               f"silently-failed mkimage during u-boot build.")
+    print(f"OK  RKNS wrapper present at 0x{IDBL_OFFSET:x}")
+
+    # Count non-0xFF bytes in the SPL/TPL region. If near-zero, the wrapper
+    # might be there but the payload got padded out.
+    region = data[IDBL_OFFSET:PAYLOAD_END]
+    content = sum(1 for b in region if b != 0xFF)
+    total = len(region)
+    pct = 100.0 * content / total
+    print(f"    payload region 0x{IDBL_OFFSET:x}..0x{PAYLOAD_END:x}:  "
+          f"{content}/{total} non-0xFF bytes ({pct:.1f}%)")
+    if content < 0x1000:
+        die(3, f"idbloader region is almost entirely 0xFF "
+               f"({content} bytes — payload missing or truncated)")
+
+    # Quick look at what's in the wrapper header for the human reader
+    w = data[IDBL_OFFSET:IDBL_OFFSET + 16]
+    size_like = struct.unpack_from("<I", w, 8)[0]
+    flag_like = struct.unpack_from("<I", w, 12)[0]
+    print(f"    wrapper[+8]=0x{size_like:08x}  wrapper[+12]=0x{flag_like:08x}")
+
+    print("\nPASS: image looks structurally sound. Safe to flash.")
+    sys.exit(0)
+
+if __name__ == "__main__":
+    if len(sys.argv) != 2:
+        print(__doc__)
+        sys.exit(1)
+    main(sys.argv[1])