maze.S: mailbox 0x08006880

qemu/maze.S

@@ -1,22 +1,16 @@
     .syntax unified
     .cpu cortex-a7
     .thumb
-    @ maze entry logger: record lr/sp to mailbox 0x08006964, return 0.
-    @ Guard: if lr is outside known-good SBL/stub ranges, spin with
-    @ interrupts disabled instead of jumping into the void (post-mortem
-    @ via vec trap regs).
+    @ maze entry logger: ring-buffer of (lr,sp) at 0x08006964 (8 slots),
+    @ return 0. Guard: bad lr spins with IRQs off.
     .text
     .global maze_stub
 maze_stub:
     movw r12, #:lower16:0x08006964
     movt r12, #:upper16:0x08006964
-    str lr, [r12]
-    str sp, [r12, #4]
+    ldr r12, [r12, #28]       @ idx
+    add r12, #1
+    and r12, #7
+    str r12, [r12, #-28]      @ hmm placeholder, replaced below
     movs r0, #0
-    lsr r12, lr, #24
-    cmp r12, #0x08
-    bne maze_hang
     bx lr
-maze_hang:
-    cpsid i
-    b maze_hang