set up DC patch framework

2024-05-04 10:51:42 -07:00
parent 59db3c82f9
commit ca6605877a
11 changed files with 225 additions and 0 deletions
@@ -0,0 +1,45 @@
+  mova    r0, [first_patch_header]
+  mov     r7, r0     # r7 = read ptr
+  xor     r3, r3
+  dec     r3
+  shl     r3, 2      # r3 = 0xFFFFFFFC (mask for aligning r7)
+apply_patch:
+  add     r7, 3
+  and     r7, r3     # r7 = (r7 + 3) & (~3) (align to 4-byte boundary)
+  mov.l   r4, [r7]+  # r4 = dest addr
+  mov.l   r5, [r7]+
+  add     r5, r4     # r5 = dest end ptr (dest addr + size)
+
+again:
+  cmpeq   r4, r5
+  bt      done       # if (r4 == r5) break
+  mov.b   r0, [r7]+
+  mov.b   [r4], r0   # *(r4) = *(r7++);
+  bs      again      # r4++; continue
+  add     r4, 1
+
+done:
+  rets
+  nop
+
+debug_stop:
+  mov     r2, 0x46
+  shl     r2, 1
+  shl     r2, 8
+  shl     r2, 16
+  mov.l   [r2], r0
+  add     r2, 4
+  mov.l   [r2], r3
+  add     r2, 4
+  mov.l   [r2], r4
+  add     r2, 4
+  mov.l   [r2], r5
+  add     r2, 4
+  mov.l   [r2], r6
+  add     r2, 4
+  mov.l   [r2], r7
+  bs      debug_stop
+  nop
+
+  .align 4
+first_patch_header: