main.c File Reference

Interactive console program to upload and execute a XIP program. More...

#include <neorv32.h>

Macros
#define	EXE_SIGNATURE   0x4788CAFE
User configuration
#define	BAUD_RATE   19200
#define	FLASH_BASE   0x00400000
#define	FLASH_ABYTES   3
#define	XIP_CLK_PRSC   CLK_PRSC_128
#define	BUFFER_SIZE   (7*1024)

Enumerations
enum	SPI_FLASH_CMD {   SPI_FLASH_CMD_WRITE = 0x02 , SPI_FLASH_CMD_READ = 0x03 , SPI_FLASH_CMD_WRITE_DISABLE = 0x04 , SPI_FLASH_CMD_READ_STATUS = 0x05 ,   SPI_FLASH_CMD_WRITE_ENABLE = 0x06 , SPI_FLASH_CMD_SECTOR_ERASE = 0xD8 }
enum	SPI_FLASH_SREG { SPI_FLASH_SREG_WIP = 0 , SPI_FLASH_SREG_WEL = 1 }

Functions
Function prototypes
int	xip_flash_access_check (void)
void	xip_flash_erase_sector (uint32_t base_addr)
void	xip_flash_program (uint32_t *src, uint32_t base_addr, uint32_t size)
int	uart_get_executable (uint32_t *dst, uint32_t *size)
uint32_t	uart_get_word (void)

RAM storage for executable
uint32_t	ram_buffer [BUFFER_SIZE/4]
int	main ()

Detailed Description

Interactive console program to upload and execute a XIP program.

Author

Stephan Nolting

Macro Definition Documentation

BAUD_RATE

#define BAUD_RATE   19200

UART BAUD rate

BUFFER_SIZE

#define BUFFER_SIZE   (7*1024)

Executable RAM buffer size in bytes

EXE_SIGNATURE

#define EXE_SIGNATURE   0x4788CAFE

Valid executable identification signature

FLASH_ABYTES

#define FLASH_ABYTES   3

Flash address bytes

FLASH_BASE

#define FLASH_BASE   0x00400000

Flash base address (32-bit)

XIP_CLK_PRSC

#define XIP_CLK_PRSC   CLK_PRSC_128

XIP SPI clock prescaler select

Enumeration Type Documentation

SPI_FLASH_CMD

enum SPI_FLASH_CMD

SPI flash commands

Enumerator
SPI_FLASH_CMD_WRITE	Write data
SPI_FLASH_CMD_READ	Read data
SPI_FLASH_CMD_WRITE_DISABLE	Disable write access
SPI_FLASH_CMD_READ_STATUS	Get status register
SPI_FLASH_CMD_WRITE_ENABLE	Enable write access
SPI_FLASH_CMD_SECTOR_ERASE	Erase complete sector

SPI_FLASH_SREG

enum SPI_FLASH_SREG

SPI flash status register

Enumerator
SPI_FLASH_SREG_WIP	Write-in-progress data
SPI_FLASH_SREG_WEL	Write-enable latch

Function Documentation

main()

int main

(

void

)

Main function

Note

This program requires the XIP module and UART0.

Returns

0 if execution was successful

uart_get_executable()

int uart_get_executable	(	uint32_t *	dst,
		uint32_t *	length )

Get NEORV32 executable via UART.

Parameters

[in]	dst	Pointer to uin32_t data array where the executable will be stored.
[out]	length	Pointer to a uin32_t to store the executable size in bytes.

Returns

Returns 0 on success.

uart_get_word()

uint32_t uart_get_word

(

void

)

Get 32-bit word from UART.

Returns

32-bit data word.

xip_flash_access_check()

int xip_flash_access_check

(

void

)

Check SPI flash connection by toggling the status register's write enable latch.

Returns

Returns 0 on success.

xip_flash_erase_sector()

void xip_flash_erase_sector

(

uint32_t

base_addr

)

Erase sector starting at base address.

Parameters

[in]

base_addr

Base address of sector to erase.

xip_flash_program()

void xip_flash_program	(	uint32_t *	src,
		uint32_t	base_addr,
		uint32_t	size )

Helper function to program the XIP flash via the direct SPI access feature of the XIP module.

Warning

This function can only be used BEFORE the XIP-mode is activated!

Note

This function is blocking and performs individual writes for each byte (little-endian byte order!).

Parameters

[in]	src	Pointer to data that will be copied to flash (32-bit).
[in]	base_addr	Image base address (in flash).
[in]	size	Image size in bytes.

Returns

Returns 0 if write was successful.

Variable Documentation

ram_buffer

uint32_t ram_buffer[BUFFER_SIZE/4]

Main function

Note

This program requires the XIP module and UART0.

Returns

0 if execution was successful