diff --git a/docs/sbl-bringup.md b/docs/sbl-bringup.md
index b409bfb..603d9e4 100644
--- a/docs/sbl-bringup.md
+++ b/docs/sbl-bringup.md
@@ -151,3 +151,9 @@
   (чётный → ARM → fault на coprocessor-мусоре). Патч в глобальной
   BLX2BL (`blx` → `bl`, как остальные). r7="SBL1", r0=SMEM — читает
   настоящие таблицы!
+
+## b31: logger-epilogue NOP (2026-09-13)
+- `0x8016320` зовёт эпилог `0x8007280`, чей pop читает fill/STUBV →
+  maze → stale-lr в logger-mid → снова blx эпилог (голая взаимная
+  рекурсия). Вызов скипается (NOP NOP); sbl_main идёт дальше
+  `0x802F6B0` в свежий код.
diff --git a/qemu/run-sbl.sh b/qemu/run-sbl.sh
index ae85b76..549c2be 100755
--- a/qemu/run-sbl.sh
+++ b/qemu/run-sbl.sh
@@ -5,7 +5,7 @@
 set -e
 cd "$(dirname "$0")/.."
 QEMU=~/qemu-src/qemu-8.2.2/build/qemu-system-arm
-B=${1:-b30}
+B=${1:-b31}
 IMG=fw/img/emmc-real.img
 if [ ! -f "$IMG" ]; then
   echo "no $IMG — сначала: python3 tools/ffu_extract.py fw/dl/RM1127_059X5R5_orig.ffu --emmc-user fw/img/user-real.bin"
diff --git a/tools/sbl_patch.py b/tools/sbl_patch.py
index 2adae95..4d36e98 100644
--- a/tools/sbl_patch.py
+++ b/tools/sbl_patch.py
@@ -1503,6 +1503,107 @@ def main():
 
     save(d, 'img0_b30.elf')
 
+    # b31 = b30 + logger-epilogue call NOP (0x8016334 bl -> NOP NOP):
+    # 0x8016320 (logger-ish) calls the shared epilogue 0x8007280, whose
+    # pop reads fill/STUBV -> maze -> stale-lr back into logger-mid ->
+    # blx epilogue again (naked mutual recursion, no stack growth).
+    # Skip the call (logger continues to its own return; sbl_main
+    # proceeds past 0x802F6B0 into fresh code). 4B NOP (was blx, b30 bl).
+    d = bytearray(base)
+
+    for va, (a, b) in BLX2BL.items():
+
+        set4(d, va, b)
+
+    for va, exp, new in [
+
+        (0x802F664, 'e4f77efc', 'c046c046'),
+
+        (0x802F672, 'e6f7bbfa', 'c046c046'),
+
+        (0x802F678, 'e9f7fef9', 'c046c046'),
+
+        (0x801B71E, '9847fee7', 'c046c046'),
+
+        (0x8008396, 'fef780f9', 'c046c046'),
+
+        (0x8016184, 'fdf790fc', 'c046c046'),
+
+        (0x801B76C, '280b0508', '00000708'),
+
+        (0x8017AFC, 'bde8fc87', 'eef74fb8'),
+
+        (0x802F690, '9847fee7', 'c046c046'),
+
+        (0x801671C, '9847fee7', 'c046c046'),
+
+        (0x8013BAC, 'f8bd0a4a', 'f3f730b8'),
+
+        (0x801B6BE, 'bde8f081', 'ebf7c3ba'),
+
+        (0x8016720, '10bd0000', 'f0f7b2ba'),
+
+        (0x8034810, 'bde8fc87', 'd2f76eba'),
+
+        (0x8007798, 'bde8f08f', 'fff7c3ba'),
+
+        (0x8016334, 'f0f7a4ff', 'c046c046'),
+
+    ]:
+
+        assert hx(d, va) == exp, (hex(va), hx(d, va))
+
+        set4(d, va, new)
+
+    # Full bl idiom at 0x8006682 (bl + pop, 6B) -> NOPs (see b18).
+    o = off(0x8006682)
+
+    assert d[o:o + 6].hex() == '00f001f807bd', hx(d, 0x8006682, 6)
+
+    d[o:o + 6] = bytes.fromhex('c046c046c046')
+
+    o = off(0x8013AA8)
+
+    assert d[o:o + 4].hex() == '07f026be', hx(d, 0x8013AA8)
+
+    d[o:o + 4] = bytes.fromhex('c046c046')
+
+    o = off(0x8013BA6)
+
+    assert d[o:o + 2].hex() == 'b888', (hex(0x8013BA6), hx(d, 0x8013BA6, 2))
+
+    d[o:o + 2] = bytes.fromhex('ff20')
+
+    # Helper-pop S16 chain (see b25).
+    o = off(0x8007B66)
+
+    assert d[o:o + 2].hex() == '10bd', hx(d, 0x8007B66, 2)
+
+    d[o:o + 2] = bytes.fromhex('6047')
+
+    # Clock S11 (see b24).
+    o = off(0x800E988)
+
+    assert d[o:o + 2].hex() == '10bd', hx(d, 0x800E988, 2)
+
+    d[o:o + 2] = bytes.fromhex('7047')
+
+    # Poll re-init skip (see b27).
+    o = off(0x8007748)
+
+    assert d[o:o + 2].hex() == '96b1', hx(d, 0x8007748, 2)
+
+    d[o:o + 2] = bytes.fromhex('14e0')
+
+    # Poll-epilogue add NOP (see b28).
+    o = off(0x8007794)
+
+    assert d[o:o + 2].hex() == '07b0', hx(d, 0x8007794, 2)
+
+    d[o:o + 2] = bytes.fromhex('c046')
+
+    save(d, 'img0_b31.elf')
+