| // Copyright lowRISC contributors. |
| // Licensed under the Apache License, Version 2.0, see LICENSE for details. |
| // SPDX-License-Identifier: Apache-2.0 |
| |
| #include "sw/device/lib/dif/dif_rv_timer.h" |
| #include "sw/device/lib/runtime/irq.h" |
| #include "sw/device/lib/runtime/log.h" |
| #include "sw/device/lib/testing/test_framework/FreeRTOSConfig.h" |
| #include "sw/device/lib/testing/test_framework/check.h" |
| |
| // TODO: make this toplevel agnostic. |
| #include "external/freertos/include/FreeRTOS.h" |
| #include "external/freertos/include/task.h" |
| #include "external/freertos/portable/GCC/RISC-V/portmacro.h" |
| |
| #include "hw/top_earlgrey/sw/autogen/top_earlgrey.h" // Generated. |
| |
| // NOTE: some of the function names below do NOT, and cannot, conform to the |
| // style guide, since they are specific implementations of FreeRTOS defined |
| // functions. |
| |
| // ---------------------------------------------------------------------------- |
| // Heap Setup |
| // |
| // We allocate the heap here and mark it so the linker can make a |
| // NOLOAD section. Otherwise, it will end up in the `.bss` section, which gets |
| // zeroed during boot initializations which wastes simulation cycles. |
| // ---------------------------------------------------------------------------- |
| __attribute__((section(".freertos.heap"))) |
| uint8_t ucHeap[configTOTAL_HEAP_SIZE]; |
| |
| // ---------------------------------------------------------------------------- |
| // Timer Setup (for use when preemptive scheduling is enabled) |
| // ---------------------------------------------------------------------------- |
| #if configUSE_PREEMPTION |
| |
| static dif_rv_timer_t timer; |
| static const uint32_t kTimerHartId = (uint32_t)kTopEarlgreyPlicTargetIbex0; |
| static const uint32_t kTimerComparatorId = 0; |
| static const uint64_t kTimerDeadline = |
| 100; // Counter must reach 100 for an IRQ to be triggered. |
| |
| // Override the timer ISR to support preemptive context switching. |
| void ottf_timer_isr(void) { |
| LOG_INFO("Handling timer IQR ..."); |
| dif_rv_timer_irq_enable_snapshot_t irq_enable_snapshot; |
| CHECK_DIF_OK( |
| dif_rv_timer_irq_disable_all(&timer, kTimerHartId, &irq_enable_snapshot)); |
| CHECK_DIF_OK(dif_rv_timer_counter_write(&timer, kTimerHartId, 0)); |
| CHECK_DIF_OK(dif_rv_timer_irq_acknowledge( |
| &timer, kDifRvTimerIrqTimerExpiredHart0Timer0)); |
| // TODO: increment scheduler tick and switch context if necessary |
| CHECK_DIF_OK( |
| dif_rv_timer_irq_restore_all(&timer, kTimerHartId, &irq_enable_snapshot)); |
| LOG_INFO("Done."); |
| } |
| |
| void vPortSetupTimerInterrupt(void) { |
| LOG_INFO("Configuring timer interrupt ..."); |
| |
| // Initialize and reset the timer. |
| CHECK_DIF_OK(dif_rv_timer_init( |
| mmio_region_from_addr(TOP_EARLGREY_RV_TIMER_BASE_ADDR), &timer)); |
| CHECK_DIF_OK(dif_rv_timer_reset(&timer)); |
| |
| // Compute and set tick parameters (i.e., step, prescale, etc.). |
| dif_rv_timer_tick_params_t tick_params; |
| CHECK_DIF_OK(dif_rv_timer_approximate_tick_params( |
| kClockFreqPeripheralHz, configTICK_RATE_HZ * kTimerDeadline, |
| &tick_params)); |
| LOG_INFO("Tick Freq. (Hz): %u, Prescale: %u; Tick Step: %u", |
| (uint32_t)kClockFreqPeripheralHz, (uint32_t)tick_params.prescale, |
| (uint32_t)tick_params.tick_step); |
| CHECK_DIF_OK(dif_rv_timer_set_tick_params(&timer, kTimerHartId, tick_params)); |
| |
| // Enable RV Timer interrupts and arm/enable the timer. |
| CHECK_DIF_OK(dif_rv_timer_irq_set_enabled( |
| &timer, kDifRvTimerIrqTimerExpiredHart0Timer0, kDifToggleEnabled)); |
| CHECK_DIF_OK(dif_rv_timer_arm(&timer, kTimerHartId, kTimerComparatorId, |
| kTimerDeadline)); |
| |
| CHECK_DIF_OK(dif_rv_timer_counter_set_enabled(&timer, kTimerHartId, |
| kDifToggleEnabled)); |
| } |
| |
| #endif // configUSE_PREEMPTION |
| |
| // ---------------------------------------------------------------------------- |
| // Scheduler Setup |
| // ---------------------------------------------------------------------------- |
| extern void xPortStartFirstTask(void); |
| |
| BaseType_t xPortStartScheduler(void) { |
| #if configUSE_PREEMPTION |
| vPortSetupTimerInterrupt(); |
| #endif // configUSE_PREEMPTION |
| irq_timer_ctrl(true); |
| irq_external_ctrl(true); |
| irq_software_ctrl(true); |
| // Note: no need to call 'irq_global_ctrl(true)' since the global interrupt |
| // enable is set in the xPortStartFirstTask sub-routine in |
| // sw/device/lib/testing/test_framework/freertos_port.S. |
| xPortStartFirstTask(); |
| |
| // Unreachable. |
| return pdFAIL; |
| } |