Hi Michel,
The simultaneous NS call has not been supported yet. Currently TF-M based on trustzone will panic when re-entry from NS is detected. So only one context for secure service call from NS task is allowed.
In the NS reference implementation,
tfm_ns_interface_dispatch ensures that only one thread calls secure service.
BR,
Xinyu
From: Michel JAOUEN via TF-M <tf-m@lists.trustedfirmware.org>
Sent: Monday, November 28, 2022 6:43 PM
To: David Wang <David.Wang@arm.com>; 'tf-m@lists.trustedfirmware.org' <tf-m@lists.trustedfirmware.org>
Subject: [TF-M] Number context for NS
Hello,
I see that in coming 1.7.0 the file secure_fw/spm/ns_client_ext/tfm_ns_ctx.h contains a comment
/* Supported maximum context for NS. Only support single context for now. */
#define TFM_NS_CONTEXT_MAX 1
Does it mean that several simultaneous NSC call is not supported ?
Best regards