b22: rollback NOP + S9v3 baked (sp reset)

2026-09-13 10:31:40 +00:00
parent c29860618f
commit f2510065ea
3 changed files with 112 additions and 7 deletions
@@ -730,6 +730,74 @@ def main():

    save(d, 'img0_b21.elf')

+    # b22 = b21 + rollback assert NOP (0x801671C blx + b.n self):
+    # boot_rollback_version.c:580 (code 0x302E) fires (versions zeroed);
+    # caller (sbl_main) ignores r0 (movs r0,#0 after), so fall-through
+    # to the success pop is safe. Same idiom as banner site.
+    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'),
+
+    ]:
+
+        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')
+
+    # Logger S8 (see b21).
+    o = off(0x8034810)
+
+    assert d[o:o + 4].hex() == 'bde8fc87', hx(d, 0x8034810)
+
+    d[o:o + 2] = bytes.fromhex('7047')
+
+    save(d, 'img0_b22.elf')
+