Improved documentation (speed vs size)

docs/compile.md

@@ -53,6 +53,16 @@ disabled with the option `NO_ARM_ASM=1`. This is useful for example when you wan
 to use SP math optimizations for key verification, but exclude SHA2/AES optimizations
 to save some space.
 
+#### Example: ECC256 + SHA256 on STM32H7
+
+Benchmark footprint vs. boot time SHA of 100KB image + signature verification
+
+| Description | Selected options | wolfBoot size (B) | Boot time (s) |
+|------|---------------|-----------------|------------|-------------------|-----------|
+| Full ECC256 assembly optimizations. Fastest. | `SIGN=ECC256` | 21836 | .583 |
+| Optimize ECC only (SP math assembly only)  | `SIGN=ECC256 NO_ARM_ASM=1` | 18624 | .760 |
+| No assembly optimizations (smallest) | `SIGN=ECC256 NO_ASM=1` | 14416 | 3.356 |
+
 
 ### Flash partitions