b29: S18 poll-epilogue router

docs/sbl-bringup.md

@@ -139,3 +139,8 @@
   `add sp,#0x1C + pop.w 0x14` (+0x30/проход, пушей нет) → марш вверх
   через fill в IMEM-нули → fault на верху. `add sp` → NOP (2B, b28).
   Pop читает helper-фреймы (pushed-lr, валидные возвраты).
+
+## b29: S18 poll-epilogue router (2026-09-13)
+- 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`.

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:-b28}
+B=${1:-b29}
 IMG=fw/img/emmc-real.img
 if [ ! -f "$IMG" ]; then
   echo "no $IMG — сначала: python3 tools/ffu_extract.py fw/dl/RM1127_059X5R5_orig.ffu --emmc-user fw/img/user-real.bin"

qemu/saimaa.c

@@ -692,6 +692,21 @@ static void saimaa_machine_init(MachineState *machine)
                     cpu_physical_memory_write(0x08006C88 + k, &word, 4);
                 }
             }
+            /* S18 stublet at 0x08006D22 (10B, b29): poll-epilogue router.
+             * movw/movt ip + bx ip to sbl_main 0x802f6a9. */
+            {
+                static const uint8_t s18[] = {
+                    0x4f, 0xf2, 0xa9, 0x6c, 0xc0, 0xf6, 0x02, 0x0c,
+                    0x60, 0x47,
+                };
+                size_t k;
+                for (k = 0; k < sizeof(s18); k += 4) {
+                    uint32_t word = 0;
+                    size_t n = sizeof(s18) - k < 4 ? sizeof(s18) - k : 4;
+                    __builtin_memcpy(&word, &s18[k], n);
+                    cpu_physical_memory_write(0x08006D22 + k, &word, 4);
+                }
+            }
             /* S17 safe-logger (50B @0x08006CF0, b26): print r1-string
              * via UARTDM-TF iff r1 in rodata [0x804B800,0x8058000);
              * pop-return (no leak). Replaces S8 silence with logs. */

tools/sbl_patch.py

@@ -1305,6 +1305,104 @@ def main():
 
     save(d, 'img0_b28.elf')
 
+    # b29 = b28 + S18 (poll-epilogue pop.w -> b.w S18):
+    # the b28 NOP killed +0x1c but pop.w 0x14 still marches (no pushes,
+    # mid-entries!). S18 (10B @0x08006D22, scaffold): movw/movt ip +
+    # bx ip to sbl_main 0x802f6a9 (post-dispatcher, dispatcher work
+    # done-ish via helpers). Blind jump like S10.
+    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_b29.elf')
+
 
 
 

tools/sbl_uni.py

@@ -393,6 +393,9 @@ def main():
     # S10 stublet (10B @0x08006C88, b23): rollback-exit router.
     # movw/movt ip + bx ip to sbl_main 0x802f6a3.
     mu.mem_write(0x08006C88, bytes.fromhex("4ff2a36cc0f6020c6047"))
+    # S18 stublet (10B @0x08006D22, b29): poll-epilogue router.
+    # movw/movt ip + bx ip to sbl_main 0x802f6a9 (post-dispatcher).
+    mu.mem_write(0x08006D22, bytes.fromhex("4ff2a96cc0f6020c6047"))
     # S17 safe-logger (50B @0x08006CF0, b26): print r1-string via
     # UARTDM-TF only if r1 in rodata [0x804B800,0x8058000); pop-return.
     mu.mem_write(0x08006CF0, bytes.fromhex(