From 110a60562c6a5201710d84d59b45cc7da3a2f386 Mon Sep 17 00:00:00 2001
From: lumia-emu <lumia-emu@local>
Date: Mon, 14 Sep 2026 00:03:57 +0000
Subject: [PATCH] b30: epilogue blx via BLX2BL

---
 docs/sbl-bringup.md |   7 ++++
 qemu/run-sbl.sh     |   2 +-
 tools/sbl_patch.py  | 100 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 108 insertions(+), 1 deletion(-)

diff --git a/docs/sbl-bringup.md b/docs/sbl-bringup.md
index af880a2..b409bfb 100644
--- a/docs/sbl-bringup.md
+++ b/docs/sbl-bringup.md
@@ -144,3 +144,10 @@
 - b28-NOP убрал только +0x1C; `pop.w 0x14` без пушей всё равно марширует.
   S18 (10B @0x08006D22): слепой прыжок в sbl_main `0x802F6A9`
   (post-dispatcher). Эпилог `pop.w` (4B) → `b.w S18`.
+
+## b30: epilogue blx (2026-09-13)
+- sbl_main дошёл до `0x8016320` (logger-ish, грузит магию "SBL1"),
+  тот зовёт shared-эпилог `0x8007280` (Thumb!) через `blx`-imm
+  (чётный → ARM → fault на coprocessor-мусоре). Патч в глобальной
+  BLX2BL (`blx` → `bl`, как остальные). r7="SBL1", r0=SMEM — читает
+  настоящие таблицы!
diff --git a/qemu/run-sbl.sh b/qemu/run-sbl.sh
index 21c149c..ae85b76 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:-b29}
+B=${1:-b30}
 IMG=fw/img/emmc-real.img
 if [ ! -f "$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 f566abf..2adae95 100644
--- a/tools/sbl_patch.py
+++ b/tools/sbl_patch.py
@@ -26,6 +26,8 @@ BLX2BL = {  # blx-imm -> bl (stay Thumb): set bit12 of 2nd halfword
 
     0x802F660: ('d8f702ec', 'd8f702fc'),
 
+    0x8016334: ('f0f7a4ef', 'f0f7a4ff'),  # blx epilogue (Thumb!) -> bl
+
 }
 
 NOPS = {  # call -> NOP NOP (skip unmodellable init/assert; r0/r5 ignored)
@@ -1403,6 +1405,104 @@ def main():
 
     save(d, 'img0_b29.elf')
 
+    # b30 = b29 + epilogue blx (0x8016334 blx -> bl, via global BLX2BL):
+    # 0x8016320 (logger-ish, loads "SBL1" magic) calls the shared
+    # epilogue 0x8007280 (Thumb: add sp + pop) via blx-imm (even->ARM!),
+    # faulting on ARM-decoded coprocessor garbage. bl stays Thumb.
+    # (Patch lives in global BLX2BL, auto-applied to all variants.)
+    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'),
+
+    ]:
+
+        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_b30.elf')
+