More documentation updates. Cleanups in the otp-keystore-gen.

Author: dgarske

docs/flash-OTP.md

@@ -89,25 +89,29 @@ make keytools
   - Copy one of the generated keys to `wolfboot_signing_private_key.der`
   - `cp 1.key wolfboot_signing_private_key.der`
 
-5) Setup the option bytes
-  - User Configuration 2 -> TrustZone Enable (TZEN=0xB4)
-  - Bank1 - Flash Watermark area (SECWM1_START=0x00, SECWM1_END=0x1F)
-  - Bank2 - Flash Watermark area (SECWM2_START=0x00, SECWM2_END=0x1F)
+5) Flash the OTP keystore primer:
 
-6) Build wolfBoot and test application using `make`
+  - Flash `./tools/keytools/otp/otp-keystore-primer.bin` to `0x08000000`
+  - Disconnect the tool and hit reset button
+  - The primer will run and flash keystore.c to OTP and enable write protection on those blocks
 
-7) Flash the OTP keystore primer:
+  OR
 
-  - Flash `./tools/keytools/otp/otp-keystore-primer.bin` to `0x08000000`
+  - Run `make otpgen` and run `./tools/keytools/otp/otp-keystore-gen` to generate an otp.bin file that can be programmed using STM32CubeProgrammer to `0x08FFF000`.
 
-8) Disconnect the tool and reboot
-  - The primer will run and flash keystore.c to OTP.
-  - Verify you flashed the keystore in OTP
+6) Verify you flashed the keystore in OTP
   - Read memory from STM32CubeProgrammer at address `0x08FFF000` (should start with ASCII "WOLFBOOT")
 
-9) Mass erase the device
+7) Setup the option bytes
+  - User Configuration 2 -> TrustZone Enable (TZEN=0xB4)
+  - Bank1 - Flash Watermark area (SECWM1_START=0x00, SECWM1_END=0x1F)
+  - Bank2 - Flash Watermark area (SECWM2_START=0x00, SECWM2_END=0x1F)
+
+8) Mass erase the device
   - STM32CubeProgrammer -> Full chip erase
 
+9) Build wolfBoot and test application using `make`
+
 10) Flash wolfBoot and test-app
 
  - Flash `wolfboot.bin` at `0x0C000000`

tools/keytools/otp/otp-keystore-gen.c

@@ -59,15 +59,17 @@ int main(void)
 
     /* Sanity check to avoid writing an empty keystore */
     if (n_keys < 1) {
-        fprintf(stderr, "Error: too few keys (%d), refusing to create %s\n", n_keys, outfile);
+        fprintf(stderr, "Error: too few keys (%d), refusing to create %s\n",
+            n_keys, outfile);
         exit(1);
     }
 
     slot_size = keystore_get_size(0);
     slot_size += KEYSTORE_HDR_SIZE;
     fprintf(stderr, "Slot size: %d\n", slot_size);
     fprintf(stderr, "Number of slots: %d\n", n_keys);
-    fprintf(stderr, "%s size: %d\n", outfile, slot_size * n_keys + sizeof(struct wolfBoot_otp_hdr));
+    fprintf(stderr, "%s size: %d\n", outfile, (slot_size * n_keys) +
+        (int)sizeof(struct wolfBoot_otp_hdr));
 
     ofd = open(outfile, O_WRONLY|O_CREAT|O_TRUNC, 0600);
     if (ofd < 0) {
@@ -84,11 +86,13 @@ int main(void)
         /* Write each public key to its slot in OTP */
         if (write(ofd, &PubKeys[i],
                 slot_size) < 0) {
-        fprintf(stderr, "Error adding key %d to %s: %s\n", i, outfile, strerror(errno));
-        exit(3);
+            fprintf(stderr, "Error adding key %d to %s: %s\n", i, outfile,
+                strerror(errno));
+            exit(3);
         }
     }
     fprintf(stderr, "%s successfully created.\nGoodbye.\n", outfile);
     close(ofd);
+
     return 0;
 }