Updated chap 28 with full expl

0x001a_operators/check_uf2.py

@@ -1,83 +0,0 @@
-"""
-Verify patched instruction and constant inside a UF2 file.
-
-Checks:
-- 0x10000410: should be 26 7a b4 ee (vsub.f32 s14, s14, s11)
-- 0x10000414: should be a6 7a b4 ee (vsub.f32 s15, s15, s11)
-- 0x1000042C: should be 00 00 00 41 (float 8.0)
-
-Usage:
-    python verify_uf2.py build/hacked.uf2
-"""
-
-import sys
-import struct
-
-UF2_MAGIC_START0 = 0x0A324655  # "UF2\n"
-UF2_MAGIC_START1 = 0x9E5D5157
-UF2_MAGIC_END    = 0x0AB16F30
-
-def load_uf2(path):
-    blocks = []
-    with open(path, "rb") as f:
-        data = f.read()
-    i = 0
-    while i + 512 <= len(data):
-        blk = data[i:i+512]
-        (m0, m1, flags, tgt_addr, payload_size, block_no,
-         num_blocks, file_size) = struct.unpack("<IIIIIIII", blk[:32])
-        if m0 != UF2_MAGIC_START0 or m1 != UF2_MAGIC_START1:
-            raise ValueError("Not a UF2 file or bad magic at block %d" % (i // 512))
-        if payload_size != 256:
-            raise ValueError("Unexpected payload size %d" % payload_size)
-        if struct.unpack("<I", blk[512-4:512])[0] != UF2_MAGIC_END:
-            raise ValueError("Bad end magic at block %d" % (i // 512))
-        payload = blk[32:32+payload_size]
-        blocks.append((tgt_addr, payload))
-        i += 512
-    return blocks
-
-def read_at(blocks, addr, length):
-    """Read 'length' bytes starting at virtual 'addr' from UF2 blocks."""
-    out = bytearray()
-    cur = addr
-    while len(out) < length:
-        # Find block that contains current address
-        hit = None
-        for base, pay in blocks:
-            if base <= cur < base + len(pay):
-                hit = (base, pay)
-                break
-        if not hit:
-            # If missing, fill with 0xFF (flash default) and continue
-            out.append(0xFF)
-            cur += 1
-            continue
-        base, pay = hit
-        out.append(pay[cur - base])
-        cur += 1
-    return bytes(out)
-
-def main():
-    if len(sys.argv) != 2:
-        print("Usage: python verify_uf2.py <path/to.uf2>")
-        sys.exit(1)
-    uf2_path = sys.argv[1]
-    blocks = load_uf2(uf2_path)
-
-    addrs = [0x10000410, 0x10000414, 0x1000042C]
-    labels = ["@10000410", "@10000414", "@1000042C"]
-
-    for label, a in zip(labels, addrs):
-        bytes_ = read_at(blocks, a, 4)
-        print(f"{label}: {bytes_.hex()} ", end="")
-        if a == 0x1000042C:
-            try:
-                print(f"(float {struct.unpack('<f', bytes_)[0]:.6f})")
-            except Exception:
-                print("(not a valid float)")
-        else:
-            print()
-
-if __name__ == "__main__":
-    main()