155 lines
4.7 KiB
C
155 lines
4.7 KiB
C
// This code is from lib/sam4e/gcc/system_sam4e.c and modified for the SAM E70
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#include <string.h> // memset
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#include "internal.h"
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/* Clock Settings (300MHz) */
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#define SYS_BOARD_OSCOUNT (CKGR_MOR_MOSCXTST(0x8U))
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#define SYS_BOARD_PLLAR (CKGR_PLLAR_ONE \
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| CKGR_PLLAR_MULA(0x18U) \
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| CKGR_PLLAR_PLLACOUNT(0x3fU) \
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| CKGR_PLLAR_DIVA_BYPASS)
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#define SYS_BOARD_MCKR (PMC_MCKR_MDIV_PCK_DIV2 | PMC_MCKR_CSS_PLLA_CLK)
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#define RST_PARAMS ((0xA5 << RSTC_CR_KEY_Pos) | RSTC_CR_PROCRST)
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#define GPNVM_TCM_MASK ((1 << 7) | (1 << 8))
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/* Key to unlock MOR register */
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#define SYS_CKGR_MOR_KEY_VALUE CKGR_MOR_KEY(0x37)
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extern uint32_t _text_size;
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extern uint32_t _dtcm_bss_start, _dtcm_bss_end;
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void
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SystemInit( void )
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{
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/* Set FWS according to SYS_BOARD_MCKR configuration */
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EFC->EEFC_FMR = EEFC_FMR_FWS(6) | EEFC_FMR_CLOE;
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/* Initialize main oscillator */
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if ( !(PMC->CKGR_MOR & CKGR_MOR_MOSCSEL) )
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{
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PMC->CKGR_MOR = (SYS_CKGR_MOR_KEY_VALUE | SYS_BOARD_OSCOUNT
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| CKGR_MOR_MOSCRCEN | CKGR_MOR_MOSCXTEN);
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while ( !(PMC->PMC_SR & PMC_SR_MOSCXTS) )
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{
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}
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}
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/* Switch to 3-20MHz Xtal oscillator */
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PMC->CKGR_MOR = (SYS_CKGR_MOR_KEY_VALUE | SYS_BOARD_OSCOUNT
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| CKGR_MOR_MOSCRCEN | CKGR_MOR_MOSCXTEN
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| CKGR_MOR_MOSCSEL);
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while ( !(PMC->PMC_SR & PMC_SR_MOSCSELS) )
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{
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}
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PMC->PMC_MCKR = ((PMC->PMC_MCKR & ~(uint32_t)PMC_MCKR_CSS_Msk)
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| PMC_MCKR_CSS_MAIN_CLK);
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while ( !(PMC->PMC_SR & PMC_SR_MCKRDY) )
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{
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}
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/* Initialize PLLA */
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PMC->CKGR_PLLAR = SYS_BOARD_PLLAR;
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while ( !(PMC->PMC_SR & PMC_SR_LOCKA) )
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{
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}
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/* Switch to main clock */
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PMC->PMC_MCKR = ((SYS_BOARD_MCKR & ~PMC_MCKR_CSS_Msk)
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| PMC_MCKR_CSS_MAIN_CLK);
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while ( !(PMC->PMC_SR & PMC_SR_MCKRDY) )
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{
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}
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/* Switch to PLLA */
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PMC->PMC_MCKR = SYS_BOARD_MCKR;
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while ( !(PMC->PMC_SR & PMC_SR_MCKRDY) )
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{
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}
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/* Configure PCK6 for TC use */
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PMC->PMC_PCK[6] = PMC_PCK_CSS_MCK | PMC_PCK_PRES(2);
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while ( !(PMC->PMC_SR & PMC_SR_PCKRDY6) )
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{
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}
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PMC->PMC_SCER |= PMC_SCER_PCK6;
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/* Check Tightly Coupled Memory (TCM) bits. */
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EFC->EEFC_FCR = (EEFC_FCR_FKEY_PASSWD | EEFC_FCR_FCMD_GGPB);
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while ((EFC->EEFC_FSR & EEFC_FSR_FRDY) == 0)
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;
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if ((EFC->EEFC_FRR & GPNVM_TCM_MASK) != GPNVM_TCM_MASK)
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{
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/* Configure TCM sizes to 128KiB (set GPNVM7 and GPNVM8). */
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EFC->EEFC_FCR = (EEFC_FCR_FKEY_PASSWD | EEFC_FCR_FCMD_SGPB
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| EEFC_FCR_FARG(7));
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while ((EFC->EEFC_FSR & EEFC_FSR_FRDY) == 0)
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;
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EFC->EEFC_FCR = (EEFC_FCR_FKEY_PASSWD| EEFC_FCR_FCMD_SGPB
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| EEFC_FCR_FARG(8));
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while ((EFC->EEFC_FSR & EEFC_FSR_FRDY) == 0)
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;
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/* Reboot required, but bits are set now and we will not
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* return down this path. */
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__DSB();
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__ISB();
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RSTC->RSTC_CR = RST_PARAMS;
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for (;;)
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;
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}
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/* Clear Data Tightly Coupled Memory (DTCM) bss segment - this has to happen
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* after we check that the DTCM is enabled. */
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memset(&_dtcm_bss_start, 0, (&_dtcm_bss_end - &_dtcm_bss_start) * 4);
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/* DMA copy flash to Instruction Tightly Coupled Memory (ITCM). Just use
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* channel 0 since we have not done anything yet. */
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enable_pclock(ID_XDMAC);
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/* Clear pending interrupts. */
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(void)REG_XDMAC_CIS0;
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REG_XDMAC_CSA0 = CONFIG_ARMCM_ITCM_FLASH_MIRROR_START;
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REG_XDMAC_CDA0 = CONFIG_FLASH_APPLICATION_ADDRESS;
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REG_XDMAC_CUBC0 = XDMAC_CUBC_UBLEN((int)&_text_size);
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REG_XDMAC_CC0 =
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XDMAC_CC_TYPE_MEM_TRAN | XDMAC_CC_MBSIZE_SINGLE |
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XDMAC_CC_CSIZE_CHK_1 | XDMAC_CC_DWIDTH_WORD |
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XDMAC_CC_SAM_INCREMENTED_AM | XDMAC_CC_DAM_INCREMENTED_AM |
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XDMAC_CC_SIF_AHB_IF1 | XDMAC_CC_DIF_AHB_IF0;
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REG_XDMAC_CNDA0 = 0;
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REG_XDMAC_CNDC0 = 0;
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REG_XDMAC_CBC0 = 0;
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REG_XDMAC_CDS_MSP0 = 0;
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REG_XDMAC_CSUS0 = 0;
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REG_XDMAC_CDUS0 = 0;
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REG_XDMAC_CIE0 = XDMAC_CIE_BIE;
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__DSB();
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__ISB();
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XDMAC->XDMAC_GE = XDMAC_GE_EN0;
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while ( XDMAC->XDMAC_GS & XDMAC_GS_ST0 )
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;
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while ( !(REG_XDMAC_CIS0 & XDMAC_CIS_BIS) )
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;
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/* Enable ITCM. DTCM is enabled by default. */
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__DSB();
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__ISB();
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SCB->ITCMCR = (SCB_ITCMCR_EN_Msk | SCB_ITCMCR_RMW_Msk
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| SCB_ITCMCR_RETEN_Msk);
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__DSB();
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__ISB();
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/* Use data cache rather than DTCM for two reasons:
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* 1. It is hard to flash this device with GPNVM bits enabled.
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* 2. It is about as fast. */
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SCB_EnableDCache();
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}
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