From b7de1d80e09fff82ce9a678eb0f88e36e6736b91 Mon Sep 17 00:00:00 2001 From: SashegDev Date: Sun, 13 Sep 2026 12:23:15 +0000 Subject: [PATCH] b29: S18 poll-epilogue router --- docs/sbl-bringup.md | 5 +++ qemu/run-sbl.sh | 2 +- qemu/saimaa.c | 15 +++++++ tools/sbl_patch.py | 98 +++++++++++++++++++++++++++++++++++++++++++++ tools/sbl_uni.py | 3 ++ 5 files changed, 122 insertions(+), 1 deletion(-) diff --git a/docs/sbl-bringup.md b/docs/sbl-bringup.md index 22606e3..af880a2 100644 --- a/docs/sbl-bringup.md +++ b/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`. diff --git a/qemu/run-sbl.sh b/qemu/run-sbl.sh index 4ae0971..21c149c 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:-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" diff --git a/qemu/saimaa.c b/qemu/saimaa.c index 53712f0..e2f1f1c 100644 --- a/qemu/saimaa.c +++ b/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. */ diff --git a/tools/sbl_patch.py b/tools/sbl_patch.py index 6bf1b1f..f566abf 100644 --- a/tools/sbl_patch.py +++ b/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') + diff --git a/tools/sbl_uni.py b/tools/sbl_uni.py index c1a1b0b..3a7c6d2 100644 --- a/tools/sbl_uni.py +++ b/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(