stubs to code zeros 0x8006820 (ring mailbox, fixed b.w)

2026-09-11 08:44:18 +00:00
parent 124e9f5e72
commit 6875e8bada
3 changed files with 35 additions and 28 deletions
@@ -1,16 +1,22 @@
    .syntax unified
    .cpu cortex-a7
    .thumb
-    @ maze entry logger: ring-buffer of (lr,sp) at 0x08006964 (8 slots),
-    @ return 0. Guard: bad lr spins with IRQs off.
+    @ maze entry logger: ring buffer of 8 (lr,sp) at MAILBOX, return 0.
+    @ Preserves all regs except r0 (return value) and r12 (IP, clobber-ok).
    .text
    .global maze_stub
 maze_stub:
-    movw r12, #:lower16:0x08006964
-    movt r12, #:upper16:0x08006964
-    ldr r12, [r12, #28]       @ idx
-    add r12, #1
-    and r12, #7
-    str r12, [r12, #-28]      @ hmm placeholder, replaced below
+    push {r0-r3}
+    movw r12, #:lower16:0x08006888
+    movt r12, #:upper16:0x08006888
+    ldr r0, [r12, #32]
+    add r0, #1
+    and r0, #7
+    str r0, [r12, #32]
+    lsl r0, #3
+    add r0, r12
+    str lr, [r0]
+    str sp, [r0, #4]
+    pop {r0-r3}
    movs r0, #0
    bx lr