b18: S7 exit router + dstub trap + docs

2026-09-12 10:30:18 +00:00
parent 67539f7351
commit 049f98122b
6 changed files with 1097 additions and 50 deletions
@@ -0,0 +1,22 @@
+    .syntax unified
+    .cpu cortex-a7
+    .thumb
+    @ Minimal PBL stub (position-independent): BLX to SBL1 entry (seg1),
+    @ then canonical regs + jump to sbl_main. Mirrors PBL call-then-jump.
+    .text
+    .global pbl_stub
+pbl_stub:
+    push {r4-r7, lr}
+    movw r12, #0x6b81
+    movt r12, #0x800
+    blx r12                   @ SBL1 entry (odd: stay Thumb)
+    movw r0, #0x0000
+    movt r0, #0x0022          @ r0 = pbl_shared 0x00220000
+    mov r5, r0
+    movw sl, #0x0000
+    movt sl, #0x0806          @ sl = table base 0x08060000
+    movw fp, #0x1000
+    movt fp, #0x0806          @ fp = 0x08061000
+    movw lr, #0xf63f
+    movt lr, #0x0802          @ lr = sbl_main odd (noreturn marker)
+    bx lr