diff --git a/evm/src/cpu/kernel/asm/sha2.asm b/evm/src/cpu/kernel/asm/sha2.asm
index 96e630d1..25261cce 100644
--- a/evm/src/cpu/kernel/asm/sha2.asm
+++ b/evm/src/cpu/kernel/asm/sha2.asm
@@ -6,153 +6,154 @@
 //               num_blocks, block0[0], block0[1], block1[0], ..., blocklast[1]
 global sha2_pad:
     // TODO: use kernel memory, and start address not at 0
+    // stack: retdest
     push 0
     mload
-    // stack: num_bytes
+    // stack: num_bytes, retdest
     // STEP 1: append 1
     // add 1 << (8*(32-k)-1) to x[num_bytes//32], where k := num_bytes%32
     dup1
-    // stack: num_bytes, num_bytes
+    // stack: num_bytes, num_bytes, retdest
     dup1
-    // stack: num_bytes, num_bytes, num_bytes
+    // stack: num_bytes, num_bytes, num_bytes, retdest
     push 32
-    // stack: 32, num_bytes, num_bytes, num_bytes
+    // stack: 32, num_bytes, num_bytes, num_bytes, retdest
     swap1
-    // stack: num_bytes, 32, num_bytes, num_bytes
+    // stack: num_bytes, 32, num_bytes, num_bytes, retdest
     mod
-    // stack: k := num_bytes % 32, num_bytes, num_bytes
+    // stack: k := num_bytes % 32, num_bytes, num_bytes, retdest
     push 32
     sub
-    // stack: 32 - k, num_bytes, num_bytes
+    // stack: 32 - k, num_bytes, num_bytes, retdest
     push 8
     mul
-    // stack: 8 * (32 - k), num_bytes, num_bytes
+    // stack: 8 * (32 - k), num_bytes, num_bytes, retdest
     %decrement
-    // stack: 8 * (32 - k) - 1, num_bytes, num_bytes
+    // stack: 8 * (32 - k) - 1, num_bytes, num_bytes, retdest
     push 1
     swap1
     shl
-    // stack: 1 << (8 * (32 - k) - 1), num_bytes, num_bytes
+    // stack: 1 << (8 * (32 - k) - 1), num_bytes, num_bytes, retdest
     swap1
-    // stack: num_bytes, 1 << (8 * (32 - k) - 1), num_bytes
+    // stack: num_bytes, 1 << (8 * (32 - k) - 1), num_bytes, retdest
     push 32
     swap1
     div
-    // stack: num_bytes // 32, 1 << (8 * (32 - k) - 1), num_bytes
+    // stack: num_bytes // 32, 1 << (8 * (32 - k) - 1), num_bytes, retdest
     dup1
-    // stack: num_bytes // 32, num_bytes // 32, 1 << (8 * (32 - k) - 1), num_bytes
+    // stack: num_bytes // 32, num_bytes // 32, 1 << (8 * (32 - k) - 1), num_bytes, retdest
     mload
-    // stack: x[num_bytes // 32], num_bytes // 32, 1 << (8 * (32 - k) - 1), num_bytes
+    // stack: x[num_bytes // 32], num_bytes // 32, 1 << (8 * (32 - k) - 1), num_bytes, retdest
     swap1
-    // stack: num_bytes // 32, x[num_bytes // 32], 1 << (8 * (32 - k) - 1), num_bytes
+    // stack: num_bytes // 32, x[num_bytes // 32], 1 << (8 * (32 - k) - 1), num_bytes, retdest
     swap2
-    // stack: x[num_bytes // 32], 1 << (8 * (32 - k) - 1), num_bytes // 32, num_bytes
+    // stack: x[num_bytes // 32], 1 << (8 * (32 - k) - 1), num_bytes // 32, num_bytes, retdest
     add
-    // stack: x[num_bytes // 32] + 1 << (8 * (32 - k) - 1), num_bytes // 32, num_bytes
+    // stack: x[num_bytes // 32] + 1 << (8 * (32 - k) - 1), num_bytes // 32, num_bytes, retdest
     swap1
-    // stack: num_bytes // 32, x[num_bytes // 32] + 1 << (8 * (32 - k) - 1), num_bytes
+    // stack: num_bytes // 32, x[num_bytes // 32] + 1 << (8 * (32 - k) - 1), num_bytes, retdest
     mstore
-    // stack: num_bytes
+    // stack: num_bytes, retdest
     // STEP 2: insert length
     // (add length := num_bytes*8+1 to x[(num_bytes//64)*2-1])
     dup1
     dup1
-    // stack: num_bytes, num_bytes, num_bytes
+    // stack: num_bytes, num_bytes, num_bytes, retdest
     push 8
     mul
     %increment
-    // stack: length := num_bytes*8+1, num_bytes, num_bytes
+    // stack: length := num_bytes*8+1, num_bytes, num_bytes, retdest
     swap1
-    // stack: num_bytes, length := num_bytes*8+1, num_bytes
+    // stack: num_bytes, length := num_bytes*8+1, num_bytes, retdest
     push 64
     swap1
     div
-    // stack: num_bytes // 64, length := num_bytes*8+1, num_bytes
+    // stack: num_bytes // 64, length := num_bytes*8+1, num_bytes, retdest
     push 2
     mul
     %decrement
-    // stack: (num_bytes // 64) * 2 - 1, length := num_bytes*8+1, num_bytes
+    // stack: (num_bytes // 64) * 2 - 1, length := num_bytes*8+1, num_bytes, retdest
     dup1
-    // stack: (num_bytes // 64) * 2 - 1, (num_bytes // 64) * 2 - 1, length, num_bytes
+    // stack: (num_bytes // 64) * 2 - 1, (num_bytes // 64) * 2 - 1, length, num_bytes, retdest
     mload
-    // stack: x[(num_bytes // 64) * 2 - 1], (num_bytes // 64) * 2 - 1, length, num_bytes
+    // stack: x[(num_bytes // 64) * 2 - 1], (num_bytes // 64) * 2 - 1, length, num_bytes, retdest
     swap1
-    // stack: (num_bytes // 64) * 2 - 1, x[(num_bytes // 64) * 2 - 1], length, num_bytes
+    // stack: (num_bytes // 64) * 2 - 1, x[(num_bytes // 64) * 2 - 1], length, num_bytes, retdest
     swap2
-    // stack: length, x[(num_bytes // 64) * 2 - 1], (num_bytes // 64) * 2 - 1, num_bytes
+    // stack: length, x[(num_bytes // 64) * 2 - 1], (num_bytes // 64) * 2 - 1, num_bytes, retdest
     add
     // stack: x[(num_bytes // 64) * 2 - 1] + length, (num_bytes // 64) * 2 - 1, num_bytes
     swap1
-    // stack: (num_bytes // 64) * 2 - 1, x[(num_bytes // 64) * 2 - 1] + length, num_bytes
+    // stack: (num_bytes // 64) * 2 - 1, x[(num_bytes // 64) * 2 - 1] + length, num_bytes, retdest
     mstore
-    // stack: num_bytes
+    // stack: num_bytes, retdest
     // STEP 3: insert num_blocks at start
     push 64
     swap
     div
     %increment
-    // stack: num_blocks := num_bytes // 64 + 1
+    // stack: num_blocks := num_bytes // 64 + 1, retdest
     push 0
     mstore
+    // stack: retdest
+    JUMP
 
 // Precodition: stack contains address of one message block, followed by output address
 // Postcondition: 64 addresses starting at given output address contain 32-bit chunks of message schedule
 global sha2_gen_message_schedule_from_block:
     JUMPDEST
-    // stack: block_addr, output_addr
+    // stack: block_addr, output_addr, retdest
     dup1
-    // stack: block_addr, block_addr, output_addr
+    // stack: block_addr, block_addr, output_addr, retdest
     %increment
-    // stack: block_addr + 1, block_addr, output_addr
+    // stack: block_addr + 1, block_addr, output_addr, retdest
     swap1
-    // stack: block_addr, block_addr + 1, output_addr
+    // stack: block_addr, block_addr + 1, output_addr, retdest
     mload
-    // stack: block[0], block_addr + 1, output_addr
+    // stack: block[0], block_addr + 1, output_addr, retdest
     swap1
-    // stack: block_addr + 1, block[0], output_addr
+    // stack: block_addr + 1, block[0], output_addr, retdest
     mload
-    // stack: block[1], block[0], output_addr
+    // stack: block[1], block[0], output_addr, retdest
     swap2
-    // stack: output_addr, block[0], block[1]
-    // stack: output_addr, block[0], block[1]
-    push 16
-    // stack: counter=16, output_addr, block[0], block[1]
+    // stack: output_addr, block[0], block[1], retdest
+    push 8
+    // stack: counter=8, output_addr, block[0], block[1], retdest
     %jump(sha2_gen_message_schedule_from_block_0_loop)
 sha2_gen_message_schedule_from_block_0_loop:
     JUMPDEST
-    // stack: counter, output_addr, block[0], block[1]
+    // stack: counter, output_addr, block[0], block[1], retdest
     swap2
-    // stack: block[0], output_addr, counter, block[1]
+    // stack: block[0], output_addr, counter, block[1], retdest
     push 1
     push 32
     shl
-    // stack: 1 << 32, block[0], output_addr, counter, block[1]
+    // stack: 1 << 32, block[0], output_addr, counter, block[1], retdest
     dup2
     dup2
-    // stack: 1 << 32, block[0], 1 << 32, block[0], output_addr, counter, block[1]
+    // stack: 1 << 32, block[0], 1 << 32, block[0], output_addr, counter, block[1], retdest
     swap1
-    // stack: block[0], 1 << 32, 1 << 32, block[0], output_addr, counter, block[1]
+    // stack: block[0], 1 << 32, 1 << 32, block[0], output_addr, counter, block[1], retdest
     mod
-    // stack: block[0] % (1 << 32), 1 << 32, block[0], output_addr, counter, block[1]
+    // stack: block[0] % (1 << 32), 1 << 32, block[0], output_addr, counter, block[1], retdest
     swap2
-    // stack: block[0], 1 << 32, block[0] % (1 << 32), output_addr, counter, block[1]
-    // stack: block[0], 1 << 32, block[0] % (1 << 32), output_addr, counter, block[1]
+    // stack: block[0], 1 << 32, block[0] % (1 << 32), output_addr, counter, block[1], retdest
     div
-    // stack: block[0] // (1 << 32), block[0] % (1 << 32), output_addr, counter, block[1]
+    // stack: block[0] // (1 << 32), block[0] % (1 << 32), output_addr, counter, block[1], retdest
     swap1
-    // stack: block[0] % (1 << 32), block[0] // (1 << 32), output_addr, counter, block[1]
+    // stack: block[0] % (1 << 32), block[0] // (1 << 32), output_addr, counter, block[1], retdest
     dup3
-    // stack: output_addr, block[0] % (1 << 32), block[0] // (1 << 32), output_addr, counter, block[1]
+    // stack: output_addr, block[0] % (1 << 32), block[0] // (1 << 32), output_addr, counter, block[1], retdest
     mstore
-    // stack: block[0] // (1 << 32), output_addr, counter, block[1]
+    // stack: block[0] // (1 << 32), output_addr, counter, block[1], retdest
     swap1
-    // stack: output_addr, block[0] // (1 << 32), counter, block[1]
+    // stack: output_addr, block[0] // (1 << 32), counter, block[1], retdest
     %increment
-    // stack: output_addr + 1, block[0] // (1 << 32), counter, block[1]
+    // stack: output_addr + 1, block[0] // (1 << 32), counter, block[1], retdest
     swap1
-    // stack: block[0] // (1 << 32), output_addr + 1, counter, block[1]
+    // stack: block[0] // (1 << 32), output_addr + 1, counter, block[1], retdest
     swap2
-    // stack: counter, output_addr + 1, block[0] // (1 << 32), block[1]
+    // stack: counter, output_addr + 1, block[0] // (1 << 32), block[1], retdest
     %decrement
     dup1
     iszero
@@ -160,67 +161,120 @@ sha2_gen_message_schedule_from_block_0_loop:
     %jump(sha2_gen_message_schedule_from_block_0_loop)
 sha2_gen_message_schedule_from_block_0_end:
     JUMPDEST
-    // stack: old counter=0, 
+    // stack: old counter=0, output_addr, block[0], block[1], retdest
     pop
-    push 16
-
+    push 8
+    // stack: counter=8, output_addr, block[0], block[1], retdest
+    swap2
+    // stack: block[0], output_addr, counter, block[1], retdest
+    swap3
+    // stack: block[1], output_addr, counter, block[0], retdest
+    swap2
+    // stack: counter, output_addr, block[1], block[0], retdest
+sha2_gen_message_schedule_from_block_1_loop:
+    JUMPDEST
+    // stack: counter, output_addr, block[1], block[0], retdest
+    swap2
+    // stack: block[1], output_addr, counter, block[0], retdest
+    push 1
+    push 32
+    shl
+    // stack: 1 << 32, block[1], output_addr, counter, block[0], retdest
+    dup2
+    dup2
+    // stack: 1 << 32, block[1], 1 << 32, block[1], output_addr, counter, block[0], retdest
+    swap1
+    // stack: block[1], 1 << 32, 1 << 32, block[1], output_addr, counter, block[0], retdest
+    mod
+    // stack: block[1] % (1 << 32), 1 << 32, block[1], output_addr, counter, block[0], retdest
+    swap2
+    // stack: block[1], 1 << 32, block[1] % (1 << 32), output_addr, counter, block[0], retdest
+    div
+    // stack: block[1] // (1 << 32), block[1] % (1 << 32), output_addr, counter, block[0], retdest
+    swap1
+    // stack: block[1] % (1 << 32), block[1] // (1 << 32), output_addr, counter, block[0], retdest
+    dup3
+    // stack: output_addr, block[1] % (1 << 32), block[1] // (1 << 32), output_addr, counter, block[0], retdest
+    mstore
+    // stack: block[1] // (1 << 32), output_addr, counter, block[0], retdest
+    swap1
+    // stack: output_addr, block[1] // (1 << 32), counter, block[0], retdest
+    %increment
+    // stack: output_addr + 1, block[1] // (1 << 32), counter, block[0], retdest
+    swap1
+    // stack: block[1] // (1 << 32), output_addr + 1, counter, block[0], retdest
+    swap2
+    // stack: counter, output_addr + 1, block[1] // (1 << 32), block[0], retdest
+    %decrement
+    dup1
+    iszero
+    %jumpi(sha2_gen_message_schedule_from_block_1_end)
+    %jump(sha2_gen_message_schedule_from_block_1_loop)
+sha2_gen_message_schedule_from_block_1_end:
+    JUMPDEST
+    // stack: old counter=0, output_addr, block[1], block[0], retdest
+    pop
+    // stack: output_addr, block[0], block[1], retdest
+    
 
 
 global sha2_message_schedule_next_word:
     JUMPDEST
-    // stack: addr
+    // stack: addr, retdest
     dup1
-    // stack: addr, addr
+    // stack: addr, addr, retdest
     push 2
     swap1
     sub
-    // stack: addr - 2, addr
+    // stack: addr - 2, addr, retdest
     mload
-    // stack: x[addr - 2], addr
+    // stack: x[addr - 2], addr, retdest
     %jump(sha2_sigma_1)
-    // stack: sigma_1(x[addr - 2]), addr
+    // stack: sigma_1(x[addr - 2]), addr, retdest
     swap1
-    // stack: addr, sigma_1(x[addr - 2])
+    // stack: addr, sigma_1(x[addr - 2]), retdest
     dup1
-    // stack: addr, addr, sigma_1(x[addr - 2])
+    // stack: addr, addr, sigma_1(x[addr - 2]), retdest
     push 7
     swap1
     sub
-    // stack: addr - 7, addr, sigma_1(x[addr - 2])
+    // stack: addr - 7, addr, sigma_1(x[addr - 2]), retdest
     mload
-    // stack: x[addr - 7], addr, sigma_1(x[addr - 2])
+    // stack: x[addr - 7], addr, sigma_1(x[addr - 2]), retdest
     swap1
-    // stack: addr, x[addr - 7], sigma_1(x[addr - 2])
+    // stack: addr, x[addr - 7], sigma_1(x[addr - 2]), retdest
     dup1
-    // stack: addr, addr, x[addr - 7], sigma_1(x[addr - 2])
+    // stack: addr, addr, x[addr - 7], sigma_1(x[addr - 2]), retdest
     push 15
     swap1
     sub
-    // stack: addr - 15, addr, x[addr - 7], sigma_1(x[addr - 2])
+    // stack: addr - 15, addr, x[addr - 7], sigma_1(x[addr - 2]), retdest
     mload
-    // stack: x[addr - 15], addr, x[addr - 7], sigma_1(x[addr - 2])
+    // stack: x[addr - 15], addr, x[addr - 7], sigma_1(x[addr - 2]), retdest
     %jump(sha2_sigma_0)
-    // stack: sigma_0(x[addr - 15]), addr, x[addr - 7], sigma_1(x[addr - 2])
+    // stack: sigma_0(x[addr - 15]), addr, x[addr - 7], sigma_1(x[addr - 2]), retdest
     swap1
-    // stack: addr, sigma_0(x[addr - 15]), x[addr - 7], sigma_1(x[addr - 2])
+    // stack: addr, sigma_0(x[addr - 15]), x[addr - 7], sigma_1(x[addr - 2]), retdest
     dup1
-    // stack: addr, addr, sigma_0(x[addr - 15]), x[addr - 7], sigma_1(x[addr - 2])
+    // stack: addr, addr, sigma_0(x[addr - 15]), x[addr - 7], sigma_1(x[addr - 2]), retdest
     push 16
     swap1
     sub
-    // stack: addr - 16, addr, sigma_0(x[addr - 15]), x[addr - 7], sigma_1(x[addr - 2])
+    // stack: addr - 16, addr, sigma_0(x[addr - 15]), x[addr - 7], sigma_1(x[addr - 2]), retdest
     mload
-    // stack: x[addr - 16], addr, sigma_0(x[addr - 15]), x[addr - 7], sigma_1(x[addr - 2])
+    // stack: x[addr - 16], addr, sigma_0(x[addr - 15]), x[addr - 7], sigma_1(x[addr - 2]), retdest
     swap1
-    // stack: addr, x[addr - 16], sigma_0(x[addr - 15]), x[addr - 7], sigma_1(x[addr - 2])
+    // stack: addr, x[addr - 16], sigma_0(x[addr - 15]), x[addr - 7], sigma_1(x[addr - 2]), retdest
     swap4
-    // stack: sigma_1(x[addr - 2]), x[addr - 16], sigma_0(x[addr - 15]), x[addr - 7], addr
+    // stack: sigma_1(x[addr - 2]), x[addr - 16], sigma_0(x[addr - 15]), x[addr - 7], addr, retdest
     add
     add
     add
-    // stack: sigma_1(x[addr - 2]) + x[addr - 16] + sigma_0(x[addr - 15]) + x[addr - 7], addr
+    // stack: sigma_1(x[addr - 2]) + x[addr - 16] + sigma_0(x[addr - 15]) + x[addr - 7], addr, retdest
     swap1
     mstore
+    // stack: retdest
+    JUMP
 
 global sha2_gen_all_message_schedules:
     JUMPDEST
diff --git a/evm/src/cpu/kernel/asm/sha2_constants.asm b/evm/src/cpu/kernel/asm/sha2_constants.asm
index 5870d961..62091bdb 100644
--- a/evm/src/cpu/kernel/asm/sha2_constants.asm
+++ b/evm/src/cpu/kernel/asm/sha2_constants.asm
@@ -644,4 +644,4 @@
     // stack i, k[i]
     pop
     // stack k[i]
-%endmacro
\ No newline at end of file
+%endmacro