PSA global data: move fields around to save code size

Move fields around to have fewer accesses outside the 128-element Thumb
direct access window.

In psa_crypto.c's global_data, put the state fields first (-20).

In psa_crypto_slot_management.c's global_data, keep the key slots first
(otherwise it's +24).

In mbedtls_psa_random_context_t, swapping entropy and drbg makes no
difference (at least when the DRBG is mbedtls_ctr_drbg_context).

Results (arm-none-eabi-gcc 7.3.1, build_arm_none_eabi_gcc_m0plus build):
library/psa_crypto.o: 16166 -> 16146 (diff: 20)

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
This commit is contained in:
Gilles Peskine 2021-11-08 22:20:03 +01:00
parent f5d7eef11f
commit b8006a66f2

View file

@ -108,9 +108,9 @@ static int key_type_is_raw_bytes( psa_key_type_t type )
typedef struct
{
mbedtls_psa_random_context_t rng;
unsigned initialized : 1;
unsigned rng_state : 2;
mbedtls_psa_random_context_t rng;
} psa_global_data_t;
static psa_global_data_t global_data;