[TF-M] Issues with qspi_ip6514e_set_spi_mode with IAR

I'm trying to bring up TF-M on the Musca A with IAR Embedded Workbench and I'm having issues in mcuboot where the boot hangs with the following stack: --- qspi_ip6514e_is_idle qspi_ip6514e_set_spi_mode set_spi_mode mt25ql_config_mode ARM_Flash_Initialize main [_call_main + 0xd] ---

Apparently the idle bit (31) in the qspi_cfg register (0x4010a000) never gets set so it loops there.

I have no programmers manual for the Cadence qspi ip6514e so I'm at a bit of a loss as to what the issue might be.

Obviously something is different between the images built with armclang and gcc, which works properly, and the image I've built with IAR.

Ideas anyone?

/Thomas