Implement bisection

x1/Makefile

@@ -24,5 +24,7 @@ spray/main.bin:
 	@./extract.py -p a.out spray/top.bin
 	@$(AS) spray/bottom.S
 	@./extract.py -p a.out spray/bottom.bin
-	@./append_nop.py 15728640 spray/top.bin spray/bottom.bin spray/main.bin
+	@$(AS) spray/bottom_reset.S
+	@./extract.py -p a.out spray/bottom_reset.bin
+	@./append_nop.py spray/top.bin spray/bottom.bin spray/bottom_reset.bin spray/main.bin 112 113
 	@rm -f a.out

x1/append_nop.py

@@ -5,20 +5,31 @@ import sys
 
 def main():
     if len(sys.argv) < 5:
-        print(f'Usage: {sys.argv[0]} N top.bin bottom.bin out.bin', file=sys.stderr)
+        print(f'Usage: {sys.argv[0]} top.bin bottom_loop.bin bottom_reset.bin out.bin reset_fill_from reset_fill_to', file=sys.stderr)
         sys.exit(1)
 
-    with open(sys.argv[2], 'rb') as topf, open(sys.argv[3], 'rb') as bottomf, open(sys.argv[4], 'wb') as out:
-        top, bottom = topf.read(), bottomf.read()
+    with open(sys.argv[1], 'rb') as tf, open(sys.argv[2], 'rb') as btmlf, open(sys.argv[3], 'rb') as btmrf, open(sys.argv[4], 'wb') as out:
+        top, btml, btmr = tf.read(), btmlf.read(), btmrf.read()
+        fill_from, fill_to = int(sys.argv[5]), int(sys.argv[6])
+
         out.write(top)
-        for i in range((1024 * 64 - len(top) - len(bottom)) // 4):
+        if fill_from == 0:
+            blen, b = len(btmr), btmr
+        else:
+            blen, b = len(btml), btml
+        for i in range((1024 * 64 - len(top) - blen) // 4):
             out.write(b'\x00\x00\xa0\xe1')
-        out.write(bottom)
+        out.write(b)
 
         for i in range(1024 * 1024 * 15 // (1024 * 64) - 1):
-            for i in range((1024 * 64 - len(bottom)) // 4):
+            if fill_from <= i+1 < fill_to:
+                blen, b = len(btmr), btmr
+            else:
+                blen, b = len(btml), btml
+
+            for j in range((1024 * 64 - blen) // 4):
                 out.write(b'\x00\x00\xa0\xe1')
-            out.write(bottom)
+            out.write(b)
 
 
 main()

x1/spray/bottom.S

@@ -4,6 +4,5 @@
 
 _start:
 loop:
+    nop
     b loop
-    ldr r0, =0x00000000
-    mov pc, r0

x1/spray/bottom_reset.S

@@ -0,0 +1,7 @@
+.text
+    .align 2
+    .global _start
+
+_start:
+    ldr r0, =0x00000000
+    mov pc, r0