diff --git a/README.md b/README.md
index 300c9db..d73873e 100644
--- a/README.md
+++ b/README.md
@@ -18,8 +18,24 @@ In u-boot use the following to boot:
 => booti 0x84000000 - ${fdtcontroladdr} 
 ```
 
-## Notes
+## Use more than 1 CPU
 
-- With only 1 CPU some thigs are soo slow to work. For example, the ttyS0 device
-  doesn't arrive on time and the login fails. Or the SSH daemon doesn't start
-  until the third try. With -smp 32 seems to work ok.
+With only 1 CPU some thigs are soo slow to work. For example, the ttyS0 device
+doesn't arrive on time and the login fails. Or the SSH daemon doesn't start
+until the third try. With -smp 32 seems to work ok.
+
+## Compressed instructions
+
+To see if a binary has compressed instructions or not, you can use objdump:
+
+    hut% nix shell -vL nixpkgs#pkgsCross.riscv64.bintools
+    hut% objdump -M no-aliases -D result/u-boot | grep 'c\.' | head -5
+        80200000:   822a                    c.mv    tp,a0
+        80200002:   84ae                    c.mv    s1,a1
+        80200018:   52c1                    c.li    t0,-16
+        8020001e:   0356                    c.slli  t1,0x15
+        80200024:   850a                    c.mv    a0,sp
+
+To dump a ROM without the ELF header:
+
+    hut% objdump -b binary -m riscv:rv64 -M no-aliases -D result/u-boot.bin