Update README.md

Author: JacobBarthelmeh

caam/seco/README.md

@@ -15,3 +15,55 @@ This is an example configure for building wolfSSL
 
 ## Additional cryptodev-linux Examples
 Examples for use in conjunction with SECO are in the cryptodev directory
+
+## Arguments
+The first argument to the examples can be a 0 or a 1. 1 is used for creating a new entry and 0 for opening an existing one.
+The second argument is the KeyID.
+The third argument is the Keystore ID.
+    
+The KeyID should be 0 if creating it for the first time.    
+    
+An example of running aes-cbc would be:    
+
+```
+#create new keystore and use arbitrary keystore ID of 9
+/tmp/aes-cbc 1 0 9
+[ 46.049273] SECO fp open
+[ 46.055038] SECO setup memory access addr 960A0000 len 66560
+[ 46.061494] SECO memreg permissions set
+[ 46.066412] SECO fp open
+[ 46.070173] SECO setup memory access addr 960C0000 len 66560
+[ 46.076634] SECO memreg permissions set
+Key ID: 581588797
+in = 0xffffe9138750
+out = 0xffffe91386b8
+cipherTxt = 0xffffe[ 46.108136] seco_mu seco_mu2: seco_mu2_ch1: Interrupted by signal
+91386d8
+Encrypting : 74657374206D65737361676520746F20
+Cipher text: E7241091DEF6ACFEE558AA23318BCE75
+Decrypted : 74657374206D65737361676520746F20
+```
+    
+    
+Then to reopen and run using the previously created key
+
+```
+#reading key ID from the previous run, re-run the example, this time opening the existing keystore
+root@imx8qxpc0mek:~# /tmp/aes-cbc 0 581588797 9
+[ 80.480629] SECO fp open
+[ 80.484912] SECO setup memory access addr 960A0000 len 66560
+[ 80.491351] SECO memreg permissions set
+[ 80.498053] SECO fp open
+[ 80.501851] SECO setup memory access addr 960C0000 len 66560
+[ 80.508357] SECO memreg permissions set
+Key ID: 581588797[ 80.516419] seco_mu seco_mu2: seco_mu2_ch1: Interrupted by signal
+
+in = 0xffffc8928500
+out = 0xffffc8928468
+cipherTxt = 0xffffc8928488
+Encrypting : 74657374206D65737361676520746F20
+Cipher text: E7241091DEF6ACFEE558AA23318BCE75
+Decrypted : 74657374206D65737361676520746F20
+```
+   
+This will create the keystores at /etc/seco_hsm . So far none of he keystores that wolfSSL creates are PERMENANT type ones, just either persistent or ephemeral. So to reset the keystore root can do "rm -rf /etc/seco_hsm" (as suggested by one of NXP's manuals on it) and reset the device.