system_gap9.c File Reference

Functions
void	system_init (void)
	Setup the microcontroller system. More...
void	system_setup_systick (uint32_t tick_rate_hz)
	Setup timer used for SysTick. More...
void	system_core_clock_update (uint32_t new_freq)
	Update the SystemCoreClock variable. More...
uint32_t	system_core_clock_get (void)
	Get current SystemCoreClock value. More...
void	system_usermode_entry (void *arg)
	Prologue for usermode thread. More...
void	system_exit (int32_t code)
	Stop execution. More...

Variables
char	__heapfcram_start
char	__heapfcram_size
char	__heapl2ram_start
char	__heapl2ram_size
volatile uint32_t	SystemCoreClock
	System clock frequency (core clock) More...
static volatile uint32_t	tick_rate

Function Documentation

uint32_t system_core_clock_get

(

void

)

Returns

Current core frequency.

References SystemCoreClock.

Referenced by __pi_spi_open(), __pi_spi_receive_async(), __pi_spi_send_async(), __pi_spi_xfer_async(), and pi_timer_irq_set().

void system_core_clock_update

(

uint32_t

new_freq

)

It must be called whenever the CPU frequency is changed during execution. This function updates SystemCoreClock variable according to current CPU frequency.

Parameters

new_freq

New SoC frequence.

References timer_cfg_u::enable, timer_cfg_u::field, timer_cfg_u::irq_en, timer_cfg_u::mode, pi_timer_conf_init(), pi_timer_init(), pi_timer_stop(), timer_cfg_u::reset, SYS_TIMER, SystemCoreClock, and tick_rate.

Referenced by pi_fll_frequency_set().

void system_exit

(

int32_t

code

)

This function is called to stop an execution and stop the microcontroller.

References hal_eu_evt_mask_clr(), hal_eu_evt_wait(), hal_itc_wait_for_interrupt(), hal_soc_ctrl_corestatus_set(), pi_is_fc(), semihost_exit(), SEMIHOST_EXIT_ERROR, SEMIHOST_EXIT_SUCCESS, soc_ctrl_corestatus_set(), and system_exit_printf_flush().

Referenced by exit().

void system_init

(

void

)

This function configures the oscillator (FLL), setup caches and IRQ. It also initializes malloc functions. this function should be called from startup_device file.

References __heapfcram_size, __heapfcram_start, __heapl2ram_size, __heapl2ram_start, __pi_pmu_init(), FC_ICACHE, FC_IRQ_SOC_EVENT_FIFO_EVT, FC_SOC_EVENT_IRQN, hal_itc_reset(), hal_soc_eu_reset_cl_mask(), hal_soc_eu_reset_fc_mask(), hal_soc_eu_reset_pr_mask(), hal_write32(), NVIC, NVIC_EnableIRQ, PENDSV_IRQN, pi_fc_event_handler_init(), pi_malloc_init(), pi_pmu_init(), printf_uart_init(), SCBC, and SOCEU.

void system_setup_systick

(

uint32_t

tick_rate_hz

)

This function sets up low timer for a given tick rate.

Parameters

tick_rate_hz

Tick rate of SysTick timer.

References timer_cfg_u::enable, timer_cfg_u::field, timer_cfg_u::irq_en, timer_cfg_u::mode, NVIC_EnableIRQ, pi_timer_conf_init(), pi_timer_init(), timer_cfg_u::reset, SYS_TIMER, SystemCoreClock, SYSTICK_IRQN, and tick_rate.

Referenced by prvSetupTimerInterrupt().

void system_usermode_entry

(

void *

arg

)

This function is called at the beginig of user threads. It harvest arguments to launch the user thread, free temp structs and drop privileges before executing the actual user thread.

References pi_user_task_arg_t::arg, ECALL_PRIV_DROP, pi_user_task_arg_t::entry, hal_compiler_barrier(), pi_fc_l1_free(), and syscall().

Referenced by __os_native_api_create_user_task().

Variable Documentation

char __heapfcram_size

char __heapfcram_start

char __heapl2ram_size

char __heapl2ram_start

volatile uint32_t SystemCoreClock

The system clock frequency supplied to the SysTick timer and the processor core clock. This variable can be used by the user application to setup the SysTick timer or configure other parameters. It may also be used by debugger to query the frequency of the debug timer or configure the trace clock speed SystemCoreClock is initialized with a correct predefined value.

Referenced by system_core_clock_get(), system_core_clock_update(), and system_setup_systick().

volatile uint32_t tick_rate

static

Referenced by system_core_clock_update(), and system_setup_systick().