Files
tinygo/src/runtime/runtime_esp32c3.go
T
Ayke van Laethem 5557e97888 device: update SVD files
This updates lib/cmsis-svd, pulling in the updates to the Espressif SVD
files here:
https://github.com/cmsis-svd/cmsis-svd-data/pull/3

This is needed for wifi/BLE support on the ESP32-C3 (the older SVD files
were missing some necessary interrupts).
2024-02-19 19:10:21 +01:00

102 lines
3.0 KiB
Go

//go:build esp32c3
package runtime
import (
"device/esp"
"device/riscv"
"machine"
"runtime/volatile"
"unsafe"
)
// This is the function called on startup after the flash (IROM/DROM) is
// initialized and the stack pointer has been set.
//
//export main
func main() {
// This initialization configures the following things:
// * It disables all watchdog timers. They might be useful at some point in
// the future, but will need integration into the scheduler. For now,
// they're all disabled.
// * It sets the CPU frequency to 160MHz, which is the maximum speed allowed
// for this CPU. Lower frequencies might be possible in the future, but
// running fast and sleeping quickly is often also a good strategy to save
// power.
// TODO: protect certain memory regions, especially the area below the stack
// to protect against stack overflows. See
// esp_cpu_configure_region_protection in ESP-IDF.
// Disable Timer 0 watchdog.
esp.TIMG0.WDTCONFIG0.Set(0)
// Disable RTC watchdog.
esp.RTC_CNTL.WDTWPROTECT.Set(0x50D83AA1)
esp.RTC_CNTL.WDTCONFIG0.Set(0)
// Disable super watchdog.
esp.RTC_CNTL.SWD_WPROTECT.Set(0x8F1D312A)
esp.RTC_CNTL.SWD_CONF.Set(esp.RTC_CNTL_SWD_CONF_SWD_DISABLE)
// Change CPU frequency from 20MHz to 80MHz, by switching from the XTAL to
// the PLL clock source (see table "CPU Clock Frequency" in the reference
// manual).
esp.SYSTEM.SYSCLK_CONF.Set(1 << esp.SYSTEM_SYSCLK_CONF_SOC_CLK_SEL_Pos)
// Change CPU frequency from 80MHz to 160MHz by setting SYSTEM_CPUPERIOD_SEL
// to 1 (see table "CPU Clock Frequency" in the reference manual).
// Note: we might not want to set SYSTEM_CPU_WAIT_MODE_FORCE_ON to save
// power. It is set here to keep the default on reset.
esp.SYSTEM.CPU_PER_CONF.Set(esp.SYSTEM_CPU_PER_CONF_CPU_WAIT_MODE_FORCE_ON | esp.SYSTEM_CPU_PER_CONF_PLL_FREQ_SEL | 1<<esp.SYSTEM_CPU_PER_CONF_CPUPERIOD_SEL_Pos)
clearbss()
// Configure interrupt handler
interruptInit()
// Initialize UART.
machine.USBCDC.Configure(machine.UARTConfig{})
machine.InitSerial()
// Initialize main system timer used for time.Now.
initTimer()
// Initialize the heap, call main.main, etc.
run()
// Fallback: if main ever returns, hang the CPU.
exit(0)
}
func abort() {
// lock up forever
for {
riscv.Asm("wfi")
}
}
// interruptInit initialize the interrupt controller and called from runtime once.
func interruptInit() {
mie := riscv.DisableInterrupts()
// Reset all interrupt source priorities to zero.
priReg := &esp.INTERRUPT_CORE0.CPU_INT_PRI_1
for i := 0; i < 31; i++ {
priReg.Set(0)
priReg = (*volatile.Register32)(unsafe.Add(unsafe.Pointer(priReg), 4))
}
// default threshold for interrupts is 5
esp.INTERRUPT_CORE0.CPU_INT_THRESH.Set(5)
// Set the interrupt address.
// Set MODE field to 1 - a vector base address (only supported by ESP32C3)
// Note that this address must be aligned to 256 bytes.
riscv.MTVEC.Set((uintptr(unsafe.Pointer(&_vector_table))) | 1)
riscv.EnableInterrupts(mie)
}
//go:extern _vector_table
var _vector_table [0]uintptr