Update docs/getting_started.md
Co-Authored-By: Gilles Peskine <gilles.peskine@arm.com>
diff --git a/docs/getting_started.md b/docs/getting_started.md
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@@ -375,7 +375,8 @@
**To calculate a hash:**
1. Allocate an operation structure (`psa_hash_operation_t`) to pass to the hash functions.
-1. Call `psa_hash_setup()` to initialize the operation structure and specify the hash algorithm.
+1. Initialize the operation structure to zero or to `PSA_HASH_OPERATION_INIT`.
+1. Call `psa_hash_setup()` to specify the hash algorithm.
1. Call `psa_hash_update()` one or more times, passing the whole message or a fragment of the message on each call.
1. Call `psa_hash_finish()` to calculate the hash, or `psa_hash_verify()` to compare the computed hash with an expected hash value.