From 42227147d4be407c738258be9d99fe0990f5f020 Mon Sep 17 00:00:00 2001 From: lumia-emu Date: Sun, 13 Sep 2026 12:08:22 +0000 Subject: [PATCH] b26: S17 safe-logger baked --- docs/sbl-bringup.md | 7 ++++ qemu/saimaa.c | 29 +++++++++++++--- tools/sbl_patch.py | 82 +++++++++++++++++++++++++++++++++++++++++++++ tools/sbl_uni.py | 7 +++- 4 files changed, 120 insertions(+), 5 deletions(-) diff --git a/docs/sbl-bringup.md b/docs/sbl-bringup.md index ba13cdf..b064cf2 100644 --- a/docs/sbl-bringup.md +++ b/docs/sbl-bringup.md @@ -113,3 +113,10 @@ 2B) → S16 проверяет ip (odd + top 8 = legit pushed-lr → `bx ip`; иначе default: restore r7, прыжок `0x8007779`). S12v3 грузит ip из `[sp+4]` (pushed lr) + ACK bit1. B66-патч в ELF (b25), S12/S16 в scaffold. + +## b26: S17 safe-logger (2026-09-13) +- S8 (`bx lr`) гасил весь init-лог (UART пуст by design) вслепую. + S17 (50B @0x08006CF0): печать r1-строки в UARTDM-TF, только если r1 + в rodata `[0x804B800,0x8058000)` (wild-указатели скипаются), затем + pop-return (без leak'а, возврат игнорируется). Логгер `0x8034810` + (`pop.w` 4B) → `b.w S17`. Видимость прогресса вместо счёта инстр. diff --git a/qemu/saimaa.c b/qemu/saimaa.c index f78696b..edff0cc 100644 --- a/qemu/saimaa.c +++ b/qemu/saimaa.c @@ -104,15 +104,15 @@ static void saimaa_tmr_init(Object *obj) /* Stubs region handle for set_readonly after scaffold implant. */ static MemoryRegion *saimaa_stubs_mr; -/* DDRLOW stub trap [0x08006B80,0x08006CF0): serves the scaffolded bytes - * (S/maze/S6/banner/S7/S9/S10/S16 stubs) on read/fetch, ignores SBL +/* DDRLOW stub trap [0x08006B80,0x08006D30): serves the scaffolded bytes + * (S/maze/S6/banner/S7/S9/S10/S16/S17 stubs) on read/fetch, ignores SBL * heap-clobber writes. Uni parity: deferred-restore guard in sbl_uni.py - * (wider: [0x080068C0,0x08006CF0), also covers PBL stub). + * (wider: [0x080068C0,0x08006D30), also covers PBL stub). * Snapshot is taken AFTER ELF load + all stub writes (readback). * PBL stub [0x080068C0,0x080068F4) and the ELF-text gap below stay plain * RAM: PBL runs once (if at all), gap holds real hot SBL code. */ #define SAIMAA_DSTUB_BASE 0x08006B80 -#define SAIMAA_DSTUB_SIZE 0x00000170 +#define SAIMAA_DSTUB_SIZE 0x000001B0 static uint8_t saimaa_dstub_mem[SAIMAA_DSTUB_SIZE]; static uint64_t saimaa_dstub_read(void *opaque, hwaddr off, unsigned size) @@ -692,6 +692,27 @@ static void saimaa_machine_init(MachineState *machine) cpu_physical_memory_write(0x08006C88 + 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. */ + { + static const uint8_t s17[] = { + 0x4b, 0xf6, 0x00, 0x03, 0xc0, 0xf6, 0x04, 0x03, + 0x99, 0x42, 0x11, 0xd3, 0x48, 0xf2, 0x00, 0x03, + 0xc0, 0xf6, 0x05, 0x03, 0x99, 0x42, 0x0b, 0xd2, + 0x10, 0xb5, 0x4f, 0xf2, 0x00, 0x03, 0xc0, 0xf2, + 0x8a, 0x73, 0x0c, 0x46, 0x14, 0xf8, 0x01, 0x0b, + 0x08, 0xb1, 0x18, 0x67, 0xfa, 0xe7, 0x10, 0xbd, + 0x70, 0x47, + }; + size_t k; + for (k = 0; k < sizeof(s17); k += 4) { + uint32_t word = 0; + size_t n = sizeof(s17) - k < 4 ? sizeof(s17) - k : 4; + __builtin_memcpy(&word, &s17[k], n); + cpu_physical_memory_write(0x08006CF0 + k, &word, 4); + } + } /* PBL version-table fabrication (b23): [0x080528D0] = STUBV * so the rollback query's blx calls maze (0 = versions OK). */ { diff --git a/tools/sbl_patch.py b/tools/sbl_patch.py index 61398e4..8701121 100644 --- a/tools/sbl_patch.py +++ b/tools/sbl_patch.py @@ -1044,6 +1044,88 @@ def main(): save(d, 'img0_b25.elf') + # b26 = b25 + S17 safe-logger (0x8034810 pop.w -> b.w S17): + # S8 (bx lr) silenced all init logging (UART empty by design). + # S17 (50B @0x08006CF0, scaffold): print r1-string via UARTDM-TF + # only if r1 in rodata [0x804B800,0x8058000) (wild pointers skip), + # then pop-return (no leak, return value ignored by callers). + 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'), + + ]: + + 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') + + save(d, 'img0_b26.elf') + diff --git a/tools/sbl_uni.py b/tools/sbl_uni.py index 2f06db7..7d15946 100644 --- a/tools/sbl_uni.py +++ b/tools/sbl_uni.py @@ -367,6 +367,11 @@ 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")) + # 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( + "4bf60003c0f60403994211d348f20003c0f605039942" + "0bd210b54ff20003c0f28a730c4614f8010b08b11867fae710bd7047")) # PBL version-table fabrication (b23): [0x080528D0] = STUBV so the # rollback query's blx calls maze (returns 0 = versions OK). W32(0x080528D0, STUBV) @@ -430,7 +435,7 @@ def main(): # --- end parity --- # stub range is readonly on HW/QEMU: ignore SBL heap-clobber writes, # keep maze/stublets intact (restore-on-write with reentrancy guard) - STUB_LO, STUB_HI = 0x080068C0, 0x08006CF0 # +S7/S9/S10/S16 + banner + STUB_LO, STUB_HI = 0x080068C0, 0x08006D30 # +S7/S9/S10/S16/S17 stub_snap = bytes(mu.mem_read(STUB_LO, STUB_HI - STUB_LO)) _inww = [False] _swn = [0]