/* Teensyduino Core Library * http://www.pjrc.com/teensy/ * Copyright (c) 2013 PJRC.COM, LLC. * Modifications by Jacob Alexander 2014-2015 * * Permission is hereby granted, free of charge, to any person obtaining * a copy of this software and associated documentation files (the * "Software"), to deal in the Software without restriction, including * without limitation the rights to use, copy, modify, merge, publish, * distribute, sublicense, and/or sell copies of the Software, and to * permit persons to whom the Software is furnished to do so, subject to * the following conditions: * * 1. The above copyright notice and this permission notice shall be * included in all copies or substantial portions of the Software. * * 2. If the Software is incorporated into a build system that allows * selection among a list of target devices, then similar target * devices manufactured by PJRC.COM must be included in the list of * target devices and selectable in the same manner. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. */ // ----- Includes ----- // Debug Includes #if defined(_bootloader_) #include #include #else #include #endif // Local Includes #include "mk20dx.h" // ----- Variables ----- extern unsigned long _stext; extern unsigned long _etext; extern unsigned long _sdata; extern unsigned long _edata; extern unsigned long _sbss; extern unsigned long _ebss; extern unsigned long _estack; const uint8_t sys_reset_to_loader_magic[22] = "\xff\x00\x7fRESET TO LOADER\x7f\x00\xff"; // ----- Function Declarations ----- extern int main(); void ResetHandler(); // ----- Interrupts ----- // NVIC - Default ISR void fault_isr() { print("Fault!" NL ); while ( 1 ) { // keep polling some communication while in fault // mode, so we don't completely die. if ( SIM_SCGC4 & SIM_SCGC4_USBOTG ) usb_isr(); if ( SIM_SCGC4 & SIM_SCGC4_UART0 ) uart0_status_isr(); if ( SIM_SCGC4 & SIM_SCGC4_UART1 ) uart1_status_isr(); if ( SIM_SCGC4 & SIM_SCGC4_UART2 ) uart2_status_isr(); } } void unused_isr() { fault_isr(); } // NVIC - SysTick ISR extern volatile uint32_t systick_millis_count; void systick_default_isr() { systick_millis_count++; } // NVIC - Non-Maskable Interrupt ISR void nmi_default_isr() { print("NMI!" NL ); } // NVIC - Hard Fault ISR void hard_fault_default_isr() { print("Hard Fault! SCB_HFSR: "); printHex32( SCB_HFSR ); print( NL ); SOFTWARE_RESET(); } // NVIC - Memory Manager Fault ISR void memmanage_fault_default_isr() { print("Memory Manager Fault! SCB_CFSR: "); printHex32( SCB_CFSR ); print(" SCB_MMAR: "); printHex32( SCB_MMAR ); print( NL ); } // NVIC - Bus Fault ISR void bus_fault_default_isr() { print("Bus Fault! SCB_CFSR: "); printHex32( SCB_CFSR ); print(" SCB_BFAR: "); printHex32( SCB_BFAR ); print( NL ); } // NVIC - Usage Fault ISR void usage_fault_default_isr() { print("Usage Fault! SCB_CFSR: "); printHex32( SCB_CFSR ); print( NL ); } // NVIC - Default ISR/Vector Linking void nmi_isr() __attribute__ ((weak, alias("nmi_default_isr"))); void hard_fault_isr() __attribute__ ((weak, alias("hard_fault_default_isr"))); void memmanage_fault_isr() __attribute__ ((weak, alias("memmanage_fault_default_isr"))); void bus_fault_isr() __attribute__ ((weak, alias("bus_fault_default_isr"))); void usage_fault_isr() __attribute__ ((weak, alias("usage_fault_default_isr"))); void svcall_isr() __attribute__ ((weak, alias("unused_isr"))); void debugmonitor_isr() __attribute__ ((weak, alias("unused_isr"))); void pendablesrvreq_isr() __attribute__ ((weak, alias("unused_isr"))); void systick_isr() __attribute__ ((weak, alias("systick_default_isr"))); void dma_ch0_isr() __attribute__ ((weak, alias("unused_isr"))); void dma_ch1_isr() __attribute__ ((weak, alias("unused_isr"))); void dma_ch2_isr() __attribute__ ((weak, alias("unused_isr"))); void dma_ch3_isr() __attribute__ ((weak, alias("unused_isr"))); void dma_ch4_isr() __attribute__ ((weak, alias("unused_isr"))); void dma_ch5_isr() __attribute__ ((weak, alias("unused_isr"))); void dma_ch6_isr() __attribute__ ((weak, alias("unused_isr"))); void dma_ch7_isr() __attribute__ ((weak, alias("unused_isr"))); void dma_ch8_isr() __attribute__ ((weak, alias("unused_isr"))); void dma_ch9_isr() __attribute__ ((weak, alias("unused_isr"))); void dma_ch10_isr() __attribute__ ((weak, alias("unused_isr"))); void dma_ch11_isr() __attribute__ ((weak, alias("unused_isr"))); void dma_ch12_isr() __attribute__ ((weak, alias("unused_isr"))); void dma_ch13_isr() __attribute__ ((weak, alias("unused_isr"))); void dma_ch14_isr() __attribute__ ((weak, alias("unused_isr"))); void dma_ch15_isr() __attribute__ ((weak, alias("unused_isr"))); void dma_error_isr() __attribute__ ((weak, alias("unused_isr"))); void mcm_isr() __attribute__ ((weak, alias("unused_isr"))); void flash_cmd_isr() __attribute__ ((weak, alias("unused_isr"))); void flash_error_isr() __attribute__ ((weak, alias("unused_isr"))); void low_voltage_isr() __attribute__ ((weak, alias("unused_isr"))); void wakeup_isr() __attribute__ ((weak, alias("unused_isr"))); void watchdog_isr() __attribute__ ((weak, alias("unused_isr"))); void i2c0_isr() __attribute__ ((weak, alias("unused_isr"))); void i2c1_isr() __attribute__ ((weak, alias("unused_isr"))); void i2c2_isr() __attribute__ ((weak, alias("unused_isr"))); void spi0_isr() __attribute__ ((weak, alias("unused_isr"))); void spi1_isr() __attribute__ ((weak, alias("unused_isr"))); void spi2_isr() __attribute__ ((weak, alias("unused_isr"))); void sdhc_isr() __attribute__ ((weak, alias("unused_isr"))); void can0_message_isr() __attribute__ ((weak, alias("unused_isr"))); void can0_bus_off_isr() __attribute__ ((weak, alias("unused_isr"))); void can0_error_isr() __attribute__ ((weak, alias("unused_isr"))); void can0_tx_warn_isr() __attribute__ ((weak, alias("unused_isr"))); void can0_rx_warn_isr() __attribute__ ((weak, alias("unused_isr"))); void can0_wakeup_isr() __attribute__ ((weak, alias("unused_isr"))); void i2s0_tx_isr() __attribute__ ((weak, alias("unused_isr"))); void i2s0_rx_isr() __attribute__ ((weak, alias("unused_isr"))); void uart0_lon_isr() __attribute__ ((weak, alias("unused_isr"))); void uart0_status_isr() __attribute__ ((weak, alias("unused_isr"))); void uart0_error_isr() __attribute__ ((weak, alias("unused_isr"))); void uart1_status_isr() __attribute__ ((weak, alias("unused_isr"))); void uart1_error_isr() __attribute__ ((weak, alias("unused_isr"))); void uart2_status_isr() __attribute__ ((weak, alias("unused_isr"))); void uart2_error_isr() __attribute__ ((weak, alias("unused_isr"))); void uart3_status_isr() __attribute__ ((weak, alias("unused_isr"))); void uart3_error_isr() __attribute__ ((weak, alias("unused_isr"))); void uart4_status_isr() __attribute__ ((weak, alias("unused_isr"))); void uart4_error_isr() __attribute__ ((weak, alias("unused_isr"))); void uart5_status_isr() __attribute__ ((weak, alias("unused_isr"))); void uart5_error_isr() __attribute__ ((weak, alias("unused_isr"))); void adc0_isr() __attribute__ ((weak, alias("unused_isr"))); void adc1_isr() __attribute__ ((weak, alias("unused_isr"))); void cmp0_isr() __attribute__ ((weak, alias("unused_isr"))); void cmp1_isr() __attribute__ ((weak, alias("unused_isr"))); void cmp2_isr() __attribute__ ((weak, alias("unused_isr"))); void ftm0_isr() __attribute__ ((weak, alias("unused_isr"))); void ftm1_isr() __attribute__ ((weak, alias("unused_isr"))); void ftm2_isr() __attribute__ ((weak, alias("unused_isr"))); void ftm3_isr() __attribute__ ((weak, alias("unused_isr"))); void cmt_isr() __attribute__ ((weak, alias("unused_isr"))); void rtc_alarm_isr() __attribute__ ((weak, alias("unused_isr"))); void rtc_seconds_isr() __attribute__ ((weak, alias("unused_isr"))); void pit0_isr() __attribute__ ((weak, alias("unused_isr"))); void pit1_isr() __attribute__ ((weak, alias("unused_isr"))); void pit2_isr() __attribute__ ((weak, alias("unused_isr"))); void pit3_isr() __attribute__ ((weak, alias("unused_isr"))); void pdb_isr() __attribute__ ((weak, alias("unused_isr"))); void usb_isr() __attribute__ ((weak, alias("unused_isr"))); void usb_charge_isr() __attribute__ ((weak, alias("unused_isr"))); void dac0_isr() __attribute__ ((weak, alias("unused_isr"))); void dac1_isr() __attribute__ ((weak, alias("unused_isr"))); void tsi0_isr() __attribute__ ((weak, alias("unused_isr"))); void mcg_isr() __attribute__ ((weak, alias("unused_isr"))); void lptmr_isr() __attribute__ ((weak, alias("unused_isr"))); void porta_isr() __attribute__ ((weak, alias("unused_isr"))); void portb_isr() __attribute__ ((weak, alias("unused_isr"))); void portc_isr() __attribute__ ((weak, alias("unused_isr"))); void portd_isr() __attribute__ ((weak, alias("unused_isr"))); void porte_isr() __attribute__ ((weak, alias("unused_isr"))); void software_isr() __attribute__ ((weak, alias("unused_isr"))); // NVIC - Interrupt Vector Table __attribute__ ((section(".vectors"), used)) void (* const gVectors[])() = { (void (*)(void))((unsigned long)&_estack), // 0 ARM: Initial Stack Pointer ResetHandler, // 1 ARM: Initial Program Counter nmi_isr, // 2 ARM: Non-maskable Interrupt (NMI) hard_fault_isr, // 3 ARM: Hard Fault memmanage_fault_isr, // 4 ARM: MemManage Fault bus_fault_isr, // 5 ARM: Bus Fault usage_fault_isr, // 6 ARM: Usage Fault fault_isr, // 7 -- fault_isr, // 8 -- fault_isr, // 9 -- fault_isr, // 10 -- svcall_isr, // 11 ARM: Supervisor call (SVCall) debugmonitor_isr, // 12 ARM: Debug Monitor fault_isr, // 13 -- pendablesrvreq_isr, // 14 ARM: Pendable req serv(PendableSrvReq) systick_isr, // 15 ARM: System tick timer (SysTick) #if defined(_mk20dx128_) || defined(_mk20dx128vlf5_) dma_ch0_isr, // 16 DMA channel 0 transfer complete dma_ch1_isr, // 17 DMA channel 1 transfer complete dma_ch2_isr, // 18 DMA channel 2 transfer complete dma_ch3_isr, // 19 DMA channel 3 transfer complete dma_error_isr, // 20 DMA error interrupt channel unused_isr, // 21 DMA -- flash_cmd_isr, // 22 Flash Memory Command complete flash_error_isr, // 23 Flash Read collision low_voltage_isr, // 24 Low-voltage detect/warning wakeup_isr, // 25 Low Leakage Wakeup watchdog_isr, // 26 Both EWM and WDOG interrupt i2c0_isr, // 27 I2C0 spi0_isr, // 28 SPI0 i2s0_tx_isr, // 29 I2S0 Transmit i2s0_rx_isr, // 30 I2S0 Receive uart0_lon_isr, // 31 UART0 CEA709.1-B (LON) status uart0_status_isr, // 32 UART0 status uart0_error_isr, // 33 UART0 error uart1_status_isr, // 34 UART1 status uart1_error_isr, // 35 UART1 error uart2_status_isr, // 36 UART2 status uart2_error_isr, // 37 UART2 error adc0_isr, // 38 ADC0 cmp0_isr, // 39 CMP0 cmp1_isr, // 40 CMP1 ftm0_isr, // 41 FTM0 ftm1_isr, // 42 FTM1 cmt_isr, // 43 CMT rtc_alarm_isr, // 44 RTC Alarm interrupt rtc_seconds_isr, // 45 RTC Seconds interrupt pit0_isr, // 46 PIT Channel 0 pit1_isr, // 47 PIT Channel 1 pit2_isr, // 48 PIT Channel 2 pit3_isr, // 49 PIT Channel 3 pdb_isr, // 50 PDB Programmable Delay Block usb_isr, // 51 USB OTG usb_charge_isr, // 52 USB Charger Detect tsi0_isr, // 53 TSI0 mcg_isr, // 54 MCG lptmr_isr, // 55 Low Power Timer porta_isr, // 56 Pin detect (Port A) portb_isr, // 57 Pin detect (Port B) portc_isr, // 58 Pin detect (Port C) portd_isr, // 59 Pin detect (Port D) porte_isr, // 60 Pin detect (Port E) software_isr, // 61 Software interrupt #elif defined(_mk20dx256_) || defined(_mk20dx256vlh7_) dma_ch0_isr, // 16 DMA channel 0 transfer complete dma_ch1_isr, // 17 DMA channel 1 transfer complete dma_ch2_isr, // 18 DMA channel 2 transfer complete dma_ch3_isr, // 19 DMA channel 3 transfer complete dma_ch4_isr, // 20 DMA channel 4 transfer complete dma_ch5_isr, // 21 DMA channel 5 transfer complete dma_ch6_isr, // 22 DMA channel 6 transfer complete dma_ch7_isr, // 23 DMA channel 7 transfer complete dma_ch8_isr, // 24 DMA channel 8 transfer complete dma_ch9_isr, // 25 DMA channel 9 transfer complete dma_ch10_isr, // 26 DMA channel 10 transfer complete dma_ch11_isr, // 27 DMA channel 10 transfer complete dma_ch12_isr, // 28 DMA channel 10 transfer complete dma_ch13_isr, // 29 DMA channel 10 transfer complete dma_ch14_isr, // 30 DMA channel 10 transfer complete dma_ch15_isr, // 31 DMA channel 10 transfer complete dma_error_isr, // 32 DMA error interrupt channel unused_isr, // 33 -- flash_cmd_isr, // 34 Flash Memory Command complete flash_error_isr, // 35 Flash Read collision low_voltage_isr, // 36 Low-voltage detect/warning wakeup_isr, // 37 Low Leakage Wakeup watchdog_isr, // 38 Both EWM and WDOG interrupt unused_isr, // 39 -- i2c0_isr, // 40 I2C0 i2c1_isr, // 41 I2C1 spi0_isr, // 42 SPI0 spi1_isr, // 43 SPI1 unused_isr, // 44 -- can0_message_isr, // 45 CAN OR'ed Message buffer (0-15) can0_bus_off_isr, // 46 CAN Bus Off can0_error_isr, // 47 CAN Error can0_tx_warn_isr, // 48 CAN Transmit Warning can0_rx_warn_isr, // 49 CAN Receive Warning can0_wakeup_isr, // 50 CAN Wake Up i2s0_tx_isr, // 51 I2S0 Transmit i2s0_rx_isr, // 52 I2S0 Receive unused_isr, // 53 -- unused_isr, // 54 -- unused_isr, // 55 -- unused_isr, // 56 -- unused_isr, // 57 -- unused_isr, // 58 -- unused_isr, // 59 -- uart0_lon_isr, // 60 UART0 CEA709.1-B (LON) status uart0_status_isr, // 61 UART0 status uart0_error_isr, // 62 UART0 error uart1_status_isr, // 63 UART1 status uart1_error_isr, // 64 UART1 error uart2_status_isr, // 65 UART2 status uart2_error_isr, // 66 UART2 error unused_isr, // 67 -- unused_isr, // 68 -- unused_isr, // 69 -- unused_isr, // 70 -- unused_isr, // 71 -- unused_isr, // 72 -- adc0_isr, // 73 ADC0 adc1_isr, // 74 ADC1 cmp0_isr, // 75 CMP0 cmp1_isr, // 76 CMP1 cmp2_isr, // 77 CMP2 ftm0_isr, // 78 FTM0 ftm1_isr, // 79 FTM1 ftm2_isr, // 80 FTM2 cmt_isr, // 81 CMT rtc_alarm_isr, // 82 RTC Alarm interrupt rtc_seconds_isr, // 83 RTC Seconds interrupt pit0_isr, // 84 PIT Channel 0 pit1_isr, // 85 PIT Channel 1 pit2_isr, // 86 PIT Channel 2 pit3_isr, // 87 PIT Channel 3 pdb_isr, // 88 PDB Programmable Delay Block usb_isr, // 89 USB OTG usb_charge_isr, // 90 USB Charger Detect unused_isr, // 91 -- unused_isr, // 92 -- unused_isr, // 93 -- unused_isr, // 94 -- unused_isr, // 95 -- unused_isr, // 96 -- dac0_isr, // 97 DAC0 unused_isr, // 98 -- tsi0_isr, // 99 TSI0 mcg_isr, // 100 MCG lptmr_isr, // 101 Low Power Timer unused_isr, // 102 -- porta_isr, // 103 Pin detect (Port A) portb_isr, // 104 Pin detect (Port B) portc_isr, // 105 Pin detect (Port C) portd_isr, // 106 Pin detect (Port D) porte_isr, // 107 Pin detect (Port E) unused_isr, // 108 -- unused_isr, // 109 -- software_isr, // 110 Software interrupt #endif }; // ----- Flash Configuration ----- // Only necessary for Teensy 3s, MCHCK uses the Bootloader to handle this #if defined(_mk20dx128_) || defined(_mk20dx256_) __attribute__ ((section(".flashconfig"), used)) const uint8_t flashconfigbytes[16] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFE, 0xFF, 0xFF, 0xFF }; #elif defined(_mk20dx128vlf5_) && defined(_bootloader_) // XXX Byte labels may be in incorrect positions, double check before modifying // FSEC is in correct location -Jacob __attribute__ ((section(".flashconfig"), used)) const uint8_t flashconfigbytes[16] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, // Backdoor Verif Key 28.3.1 // // Protecting the first 4k of Flash memory from being over-written while running (bootloader protection) // Still possible to overwrite the bootloader using an external flashing device // For more details see: // http://cache.freescale.com/files/training/doc/dwf/AMF_ENT_T1031_Boston.pdf (page 8) // http://cache.freescale.com/files/microcontrollers/doc/app_note/AN4507.pdf // http://cache.freescale.com/files/32bit/doc/ref_manual/K20P48M50SF0RM.pdf (28.34.6) // 0xFF, 0xFF, 0xFF, 0xFE, // Program Flash Protection Bytes FPROT0-3 0xBE, // Flash security byte FSEC 0x03, // Flash nonvolatile option byte FOPT 0xFF, // EEPROM Protection Byte FEPROT 0xFF, // Data Flash Protection Byte FDPROT }; #elif defined(_mk20dx256vlh7_) && defined(_bootloader_) // XXX Byte labels may be in incorrect positions, double check before modifying // FSEC is in correct location -Jacob __attribute__ ((section(".flashconfig"), used)) const uint8_t flashconfigbytes[16] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, // Backdoor Verif Key 28.3.1 // // Protecting the first 8k of Flash memory from being over-written while running (bootloader protection) // Still possible to overwrite the bootloader using an external flashing device // For more details see: // http://cache.freescale.com/files/training/doc/dwf/AMF_ENT_T1031_Boston.pdf (page 8) // http://cache.freescale.com/files/microcontrollers/doc/app_note/AN4507.pdf // http://cache.freescale.com/files/32bit/doc/ref_manual/K20P64M72SF1RM.pdf (28.34.6) // 0xFF, 0xFF, 0xFF, 0xFE, // Program Flash Protection Bytes FPROT0-3 0xBE, // Flash security byte FSEC 0x03, // Flash nonvolatile option byte FOPT 0xFF, // EEPROM Protection Byte FEPROT 0xFF, // Data Flash Protection Byte FDPROT }; #endif // ----- Functions ----- #if ( defined(_mk20dx128vlf5_) || defined(_mk20dx256vlh7_) ) && defined(_bootloader_) // Bootloader Section __attribute__((noreturn)) static inline void jump_to_app( uintptr_t addr ) { // addr is in r0 __asm__("ldr sp, [%[addr], #0]\n" "ldr pc, [%[addr], #4]" :: [addr] "r" (addr)); // NOTREACHED __builtin_unreachable(); } #endif void *memset( void *addr, int val, unsigned int len ) { char *buf = addr; for (; len > 0; --len, ++buf) *buf = val; return (addr); } int memcmp( const void *a, const void *b, unsigned int len ) { const uint8_t *ap = a, *bp = b; int val = 0; for (; len > 0 && (val = *ap - *bp) == 0; --len, ++ap, ++bp) /* NOTHING */; return (val); } void *memcpy( void *dst, const void *src, unsigned int len ) { char *dstbuf = dst; const char *srcbuf = src; for (; len > 0; --len, ++dstbuf, ++srcbuf) *dstbuf = *srcbuf; return (dst); } // ----- Chip Entry Point ----- __attribute__ ((section(".startup"))) void ResetHandler() { #if ( defined(_mk20dx128vlf5_) || defined(_mk20dx256vlh7_) ) && defined(_bootloader_) // Bootloader Section extern uint32_t _app_rom; // We treat _app_rom as pointer to directly read the stack // pointer and check for valid app code. This is no fool // proof method, but it should help for the first flash. // // Purposefully disabling the watchdog *after* the reset check this way // if the chip goes into an odd state we'll reset to the bootloader (invalid firmware image) // RCM_SRS0 & 0x20 // // Also checking for ARM lock-up signal (invalid firmware image) // RCM_SRS1 & 0x02 if ( // PIN (External Reset Pin/Switch) RCM_SRS0 & 0x40 // WDOG (Watchdog timeout) || RCM_SRS0 & 0x20 // LOCKUP (ARM Core LOCKUP event) || RCM_SRS1 & 0x02 // Blank flash check || _app_rom == 0xffffffff // Software reset || memcmp( (uint8_t*)&VBAT, sys_reset_to_loader_magic, sizeof(sys_reset_to_loader_magic) ) == 0 ) { memset( (uint8_t*)&VBAT, 0, sizeof(VBAT) ); } else { uint32_t addr = (uintptr_t)&_app_rom; SCB_VTOR = addr; // relocate vector table jump_to_app( addr ); } #endif // Disable Watchdog WDOG_UNLOCK = WDOG_UNLOCK_SEQ1; WDOG_UNLOCK = WDOG_UNLOCK_SEQ2; WDOG_STCTRLH = WDOG_STCTRLH_ALLOWUPDATE; uint32_t *src = (uint32_t*)&_etext; uint32_t *dest = (uint32_t*)&_sdata; // Enable clocks to always-used peripherals SIM_SCGC5 = 0x00043F82; // Clocks active to all GPIO SIM_SCGC6 = SIM_SCGC6_FTM0 | SIM_SCGC6_FTM1 | SIM_SCGC6_ADC0 | SIM_SCGC6_FTFL; #if defined(_mk20dx128_) SIM_SCGC6 |= SIM_SCGC6_RTC; #elif defined(_mk20dx256_) || defined(_mk20dx256vlh7_) SIM_SCGC3 = SIM_SCGC3_ADC1 | SIM_SCGC3_FTM2; SIM_SCGC6 |= SIM_SCGC6_RTC; #endif #if defined(_mk20dx128_) || defined(_mk20dx256_) // Teensy 3s // if the RTC oscillator isn't enabled, get it started early if ( !(RTC_CR & RTC_CR_OSCE) ) { RTC_SR = 0; RTC_CR = RTC_CR_SC16P | RTC_CR_SC4P | RTC_CR_OSCE; } #endif // release I/O pins hold, if we woke up from VLLS mode if ( PMC_REGSC & PMC_REGSC_ACKISO ) { PMC_REGSC |= PMC_REGSC_ACKISO; } // Prepare RAM while ( dest < (uint32_t*)&_edata ) *dest++ = *src++; dest = (uint32_t*)&_sbss; while ( dest < (uint32_t*)&_ebss ) *dest++ = 0; // MCHCK / Kiibohd-dfu #if defined(_mk20dx128vlf5_) // Default all interrupts to medium priority level for ( unsigned int i = 0; i < NVIC_NUM_INTERRUPTS; i++ ) { NVIC_SET_PRIORITY( i, 128 ); } // FLL at 48MHz MCG_C4 = MCG_C4_DMX32 | MCG_C4_DRST_DRS( 1 ); // USB Clock and FLL select SIM_SOPT2 = SIM_SOPT2_USBSRC | SIM_SOPT2_TRACECLKSEL; // Teensy 3.0 and 3.1 and Kiibohd-dfu (mk20dx256vlh7) #else #if defined(_mk20dx128_) || defined(_mk20dx256_) // use vector table in flash SCB_VTOR = 0; #endif // default all interrupts to medium priority level for ( unsigned int i = 0; i < NVIC_NUM_INTERRUPTS; i++ ) { NVIC_SET_PRIORITY( i, 128 ); } // start in FEI mode // enable capacitors for crystal OSC0_CR = OSC_SC8P | OSC_SC2P; // enable osc, 8-32 MHz range, low power mode MCG_C2 = MCG_C2_RANGE0( 2 ) | MCG_C2_EREFS; // switch to crystal as clock source, FLL input = 16 MHz / 512 MCG_C1 = MCG_C1_CLKS( 2 ) | MCG_C1_FRDIV( 4 ); // wait for crystal oscillator to begin while ( (MCG_S & MCG_S_OSCINIT0) == 0 ); // wait for FLL to use oscillator while ( (MCG_S & MCG_S_IREFST) != 0 ); // wait for MCGOUT to use oscillator while ( (MCG_S & MCG_S_CLKST_MASK) != MCG_S_CLKST( 2 ) ); // now we're in FBE mode #if F_CPU == 72000000 // config PLL input for 16 MHz Crystal / 8 = 2 MHz MCG_C5 = MCG_C5_PRDIV0( 7 ); #else // config PLL input for 16 MHz Crystal / 4 = 4 MHz MCG_C5 = MCG_C5_PRDIV0( 3 ); #endif #if F_CPU == 72000000 // config PLL for 72 MHz output (36 * 2 MHz Ext PLL) MCG_C6 = MCG_C6_PLLS | MCG_C6_VDIV0( 12 ); #else // config PLL for 96 MHz output MCG_C6 = MCG_C6_PLLS | MCG_C6_VDIV0( 0 ); #endif // wait for PLL to start using xtal as its input while ( !(MCG_S & MCG_S_PLLST) ); // wait for PLL to lock while ( !(MCG_S & MCG_S_LOCK0) ); // now we're in PBE mode #if F_CPU == 96000000 // config divisors: 96 MHz core, 48 MHz bus, 24 MHz flash SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1( 0 ) | SIM_CLKDIV1_OUTDIV2( 1 ) | SIM_CLKDIV1_OUTDIV4( 3 ); #elif F_CPU == 72000000 // config divisors: 72 MHz core, 36 MHz bus, 24 MHz flash SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1( 0 ) | SIM_CLKDIV1_OUTDIV2( 1 ) | SIM_CLKDIV1_OUTDIV4( 2 ); #elif F_CPU == 48000000 // config divisors: 48 MHz core, 48 MHz bus, 24 MHz flash SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1( 1 ) | SIM_CLKDIV1_OUTDIV2( 1 ) | SIM_CLKDIV1_OUTDIV4( 3 ); #elif F_CPU == 24000000 // config divisors: 24 MHz core, 24 MHz bus, 24 MHz flash SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1( 3 ) | SIM_CLKDIV1_OUTDIV2( 3 ) | SIM_CLKDIV1_OUTDIV4( 3 ); #else #error "Error, F_CPU must be 96000000, 72000000, 48000000, or 24000000" #endif // switch to PLL as clock source, FLL input = 16 MHz / 512 MCG_C1 = MCG_C1_CLKS( 0 ) | MCG_C1_FRDIV( 4 ); // wait for PLL clock to be used while ( (MCG_S & MCG_S_CLKST_MASK) != MCG_S_CLKST( 3 ) ); // now we're in PEE mode #if F_CPU == 72000000 // configure USB for 48 MHz clock SIM_CLKDIV2 = SIM_CLKDIV2_USBDIV( 2 ) | SIM_CLKDIV2_USBFRAC; // USB = 72 MHz PLL / 1.5 #else // configure USB for 48 MHz clock SIM_CLKDIV2 = SIM_CLKDIV2_USBDIV( 1 ); // USB = 96 MHz PLL / 2 #endif // USB uses PLL clock, trace is CPU clock, CLKOUT=OSCERCLK0 SIM_SOPT2 = SIM_SOPT2_USBSRC | SIM_SOPT2_PLLFLLSEL | SIM_SOPT2_TRACECLKSEL | SIM_SOPT2_CLKOUTSEL( 6 ); #endif #if !defined(_bootloader_) // Initialize the SysTick counter SYST_RVR = (F_CPU / 1000) - 1; SYST_CSR = SYST_CSR_CLKSOURCE | SYST_CSR_TICKINT | SYST_CSR_ENABLE; __enable_irq(); #else // Disable Watchdog for bootloader WDOG_STCTRLH &= ~WDOG_STCTRLH_WDOGEN; #endif main(); while ( 1 ); // Shouldn't get here... } // ----- RAM Setup ----- char *__brkval = (char *)&_ebss; void * _sbrk( int incr ) { char *prev = __brkval; __brkval += incr; return prev; } // ----- Interrupt Execution Priority ----- int nvic_execution_priority() { int priority = 256; uint32_t primask, faultmask, basepri, ipsr; // full algorithm in ARM DDI0403D, page B1-639 // this isn't quite complete, but hopefully good enough asm volatile( "mrs %0, faultmask\n" : "=r" (faultmask):: ); if ( faultmask ) { return -1; } asm volatile( "mrs %0, primask\n" : "=r" (primask):: ); if ( primask ) { return 0; } asm volatile( "mrs %0, ipsr\n" : "=r" (ipsr):: ); if ( ipsr ) { if ( ipsr < 16) { priority = 0; // could be non-zero } else { priority = NVIC_GET_PRIORITY( ipsr - 16 ); } } asm volatile( "mrs %0, basepri\n" : "=r" (basepri):: ); if ( basepri > 0 && basepri < priority ) { priority = basepri; } return priority; }