In this new memory partition, secure program is most simplified and non-secure program can make most use of memory for its large application like Pelion:
- Flash (512KiB in total): 64KiB for secure and 448KiB for nonsecure.
- SRAM (96KiB in total): 8KiB for secure and 88KiB for nonsecure.
Besides, to make secure program fit into 8KiB:
- Decrease boot stack size to 0x600 bytes
- Remove serial support
- Remove LPTICKER
Re-build default secure image/gateway library to favor Pelion client application
Consider the following factors to define WDT reset delay:
1. Cannot be too small. This is to avoid premature WDT reset in pieces of timeout cascading.
2. Cannot be too large. This is to pass Greentea reset_reason/watchdog_reset tests, which have e.g. 50~100 reset delay tolerance.
Original implementation doesn't enable watchdog reset in pieces of cascaded timeout, except the last one. This is to guarantee re-configuration can be in time, but in interrupt disabled scenario e.g. Hard Fault, watchdog reset can cease to be effective.
This change enables watchdog reset all the way of cascaded timeout. With trade-off, guaranteed watchdog reset function is more significant than re-configuration in time.
At IAR linking, the default method of 'initialize by copy' is 'auto', which will estimate
different packing algorithms, including complex 'lz77', for smallest memory footprint. But
the algorithm itself can consume some SRAM and cause OOM at linking time for NANO130, which
just has 16KiB SRAM. To avoid this error, always choose 'none' packing algorithm.
These targets below just support PRNG, not real TRNG. They cannot annouce TRNG.
- NUMAKER_PFM_NUC472
- NUMAKER_PFM_M487
- NUMAKER_IOT_M487
On targets without TRNG, to run mbedtls applications which require entropy source,
there are two alternatives to TRNG:
- Custom entropy source:
Define MBEDTLS_ENTROPY_HARDWARE_ALT and provide custom mbedtls_hardware_poll(...)
- NV seed:
1. Define MBEDTLS_ENTROPY_NV_SEED
2. Define MBEDTLS_PLATFORM_NV_SEED_READ_MACRO/MBEDTLS_PLATFORM_NV_SEED_WRITE_MACRO and provide custom mbedtls_nv_seed_read(...)/mbedtls_nv_seed_write(...).
3. Don't define MBEDTLS_PSA_INJECT_ENTROPY. Meet mbedtls_psa_inject_entropy(...) undefined and then provide custom one, which must be compatible with mbedtls_nv_seed_read(...)/mbedtls_nv_seed_write(...) above.
4. For development, simulating partial provision process, inject entropy seed via mbedtls_psa_inject_entropy(...) pre-main.
Reasons to remove TRNG support:
1. M252 just has 32KiB SRAM and cannot afford mbedtls application.
2. Implementing TRNG HAL with PRNG H/W has security concern.
Without free-up of peripheral pins, peripheral pins of the same peripheral may
share by multiple ports after port iteration, and this peripheral may fail with
pin interference.
In Nuvoton, only new-design chips support GPIO input pull-high/pull-low modes.
Targets not supporting this feature are listed below:
- NUMAKER_PFM_NANO130
- NUMAKER_PFM_NUC472
- NUMAKER_PFM_M453
Fix logic error on replying NACK at the end of transfer.
This is also to fix FPGA CI test mbed_hal_fpga_ci_test_shield-i2c/
i2c - test single byte read i2c API.
Better IP initialization sequence:
1. Configure IP pins
2. Select IP clock source and then enable it
3. Reset the IP (SYS_ResetModule)
NOTE1: IP reset takes effect regardless of IP clock. So it doesn't matter if
IP clock enable is before IP reset.
NOTE2: Non-configured pins may disturb IP's state, so IP pinout first and then
IP reset.
NOTE3: IP reset at the end of IP initialization sequence can cover unexpected
situation.
Without free-up of peripheral pins, peripheral pins of the same peripheral may
share by multiple ports after port iteration, and this peripheral may fail with
pin interference.
In Nuvoton, only new-design chips support GPIO input pull-high/pull-low modes.
Targets not supporting this feature are listed below:
- NUMAKER_PFM_NANO130
- NUMAKER_PFM_NUC472
- NUMAKER_PFM_M453
Fix logic error on replying NACK at the end of transfer.
This is also to fix FPGA CI test mbed_hal_fpga_ci_test_shield-i2c/
i2c - test single byte read i2c API.
Better IP initialization sequence:
1. Configure IP pins
2. Select IP clock source and then enable it
3. Reset the IP (SYS_ResetModule)
NOTE1: IP reset takes effect regardless of IP clock. So it doesn't matter if
IP clock enable is before IP reset.
NOTE2: Non-configured pins may disturb IP's state, so IP pinout first and then
IP reset.
NOTE3: IP reset at the end of IP initialization sequence can cover unexpected
situation.
Chun-Chieh Li
Martin Kojtal
int_szyk
cyliangtw