Default NEORV32 bootloader. More...

#include <stdint.h>
#include <neorv32.h>

Macros
#define	EXE_SIGNATURE 0x4788CAFE

Bootloader configuration (override via console to customize);
default values are used if not explicitly customized
#define	EXE_BASE_ADDR 0x00000000UL

#define	UART_EN 1

#define	UART_BAUD 19200

#define	UART_HW_HANDSHAKE_EN 0

#define	STATUS_LED_EN 1

#define	STATUS_LED_PIN 0

#define	AUTO_BOOT_TIMEOUT 10

#define	SPI_EN 1

#define	SPI_FLASH_CS 0

#define	SPI_FLASH_ADDR_BYTES 3

#define	SPI_FLASH_SECTOR_SIZE 65536

#define	SPI_FLASH_CLK_PRSC CLK_PRSC_8

#define	SPI_BOOT_BASE_ADDR 0x00400000UL

#define	XIP_EN 1


#define	xstr(a)

#define	str(a)

#define	PRINT_TEXT(...)

#define	PRINT_XNUM(a)

#define	PRINT_GETC(a)

#define	PRINT_PUTC(a)

Enumerations
enum	EXE_STREAM_SOURCE_enum { EXE_STREAM_UART = 0 , EXE_STREAM_FLASH = 1 }

enum	ERROR_CODES_enum { ERROR_SIGNATURE = 0 , ERROR_SIZE = 1 , ERROR_CHECKSUM = 2 , ERROR_FLASH = 3 }

enum	SPI_FLASH_CMD_enum { SPI_FLASH_CMD_PAGE_PROGRAM = 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_WAKE = 0xAB , SPI_FLASH_CMD_SECTOR_ERASE = 0xD8 }

enum	SPI_FLASH_SREG_enum { FLASH_SREG_BUSY = 0 , FLASH_SREG_WEL = 1 }

enum	NEORV32_EXECUTABLE_enum { EXE_OFFSET_SIGNATURE = 0 , EXE_OFFSET_SIZE = 4 , EXE_OFFSET_CHECKSUM = 8 , EXE_OFFSET_DATA = 12 }

Functions
void	bootloader_trap_handler (void)

void	print_help (void)

void	start_app (int boot_xip)

void	get_exe (int src)

void	save_exe (void)

uint32_t	get_exe_word (int src, uint32_t addr)

void	system_error (uint8_t err_code)

void	print_hex_word (uint32_t num)

void	spi_flash_wakeup (void)

int	spi_flash_check (void)

uint8_t	spi_flash_read_byte (uint32_t addr)

void	spi_flash_write_byte (uint32_t addr, uint8_t wdata)

void	spi_flash_write_word (uint32_t addr, uint32_t wdata)

void	spi_flash_erase_sector (uint32_t addr)

void	spi_flash_write_enable (void)

void	spi_flash_write_disable (void)

uint8_t	spi_flash_read_status (void)

void	spi_flash_write_addr (uint32_t addr)

int	main (void)

Variables
const char	error_message [4][5]

volatile uint32_t	exe_available

volatile uint32_t	getting_exe

Detailed Description

Default NEORV32 bootloader.

Macro Definition Documentation

◆ AUTO_BOOT_TIMEOUT

#define AUTO_BOOT_TIMEOUT 10

Time until the auto-boot sequence starts (in seconds); 0 = disabled

◆ EXE_BASE_ADDR

#define EXE_BASE_ADDR 0x00000000UL

Memory base address for the executable

◆ EXE_SIGNATURE

#define EXE_SIGNATURE 0x4788CAFE

Valid executable identification signature

◆ PRINT_GETC

#define PRINT_GETC ( a )

Value:

0

Helper macros Actual define-to-string helper

◆ PRINT_PUTC

#define PRINT_PUTC ( a )

Helper macros Actual define-to-string helper

◆ PRINT_TEXT

#define PRINT_TEXT ( ... )

Print to UART 0

◆ PRINT_XNUM

#define PRINT_XNUM ( a )

Helper macros Actual define-to-string helper

◆ SPI_BOOT_BASE_ADDR

#define SPI_BOOT_BASE_ADDR 0x00400000UL

SPI flash boot base address

◆ SPI_EN

#define SPI_EN 1

Enable SPI (default) including SPI flash boot options

◆ SPI_FLASH_ADDR_BYTES

#define SPI_FLASH_ADDR_BYTES 3

SPI flash address width (in numbers of bytes; 2,3,4)

◆ SPI_FLASH_CLK_PRSC

#define SPI_FLASH_CLK_PRSC CLK_PRSC_8

SPI flash clock pre-scaler; see NEORV32_SPI_CTRL_enum

◆ SPI_FLASH_CS

#define SPI_FLASH_CS 0

SPI flash chip select (low-active) at SPI.spi_csn_o(SPI_FLASH_CS)

◆ SPI_FLASH_SECTOR_SIZE

#define SPI_FLASH_SECTOR_SIZE 65536

SPI flash sector size in bytes

◆ STATUS_LED_EN

#define STATUS_LED_EN 1

Set to 0 to disable bootloader status LED (heart beat) at GPIO.gpio_o(STATUS_LED_PIN)

◆ STATUS_LED_PIN

#define STATUS_LED_PIN 0

GPIO output pin for high-active bootloader status LED (heart beat)

◆ str

#define str ( a )

Value:

#a

Internal helper macro

◆ UART_BAUD

#define UART_BAUD 19200

UART BAUD rate for serial interface

◆ UART_EN

#define UART_EN 1

Set to 0 to disable UART interface

◆ UART_HW_HANDSHAKE_EN

#define UART_HW_HANDSHAKE_EN 0

Set to 1 to enable UART HW handshaking

◆ XIP_EN

#define XIP_EN 1

Enable XIP boot options

◆ xstr

#define xstr ( a )

Value:

str(a)

str

#define str(a)

Definition bootloader.c:187

Helper macros Actual define-to-string helper

Enumeration Type Documentation

◆ ERROR_CODES_enum

enum ERROR_CODES_enum

Error codes

Enumerator
ERROR_SIGNATURE	0: Wrong signature in executable
ERROR_SIZE	1: Insufficient instruction memory capacity
ERROR_CHECKSUM	2: Checksum error in executable
ERROR_FLASH	3: SPI flash access error

◆ EXE_STREAM_SOURCE_enum

enum EXE_STREAM_SOURCE_enum

Executable stream source select (for copying into IMEM)

Enumerator
EXE_STREAM_UART	Get executable via UART
EXE_STREAM_FLASH	Get executable via SPI flash

◆ NEORV32_EXECUTABLE_enum

enum NEORV32_EXECUTABLE_enum

NEORV32 executable

Enumerator
EXE_OFFSET_SIGNATURE	Offset in bytes from start to signature (32-bit)
EXE_OFFSET_SIZE	Offset in bytes from start to size (32-bit)
EXE_OFFSET_CHECKSUM	Offset in bytes from start to checksum (32-bit)
EXE_OFFSET_DATA	Offset in bytes from start to data (32-bit)

◆ SPI_FLASH_CMD_enum

enum SPI_FLASH_CMD_enum

SPI flash commands

Enumerator
SPI_FLASH_CMD_PAGE_PROGRAM	Program page
SPI_FLASH_CMD_READ	Read data
SPI_FLASH_CMD_WRITE_DISABLE	Disallow write access
SPI_FLASH_CMD_READ_STATUS	Get status register
SPI_FLASH_CMD_WRITE_ENABLE	Allow write access
SPI_FLASH_CMD_WAKE	Wake up from sleep mode
SPI_FLASH_CMD_SECTOR_ERASE	Erase complete sector

◆ SPI_FLASH_SREG_enum

enum SPI_FLASH_SREG_enum

SPI flash status register bits

Enumerator
FLASH_SREG_BUSY	Busy, write/erase in progress when set, read-only
FLASH_SREG_WEL	Write access enabled when set, read-only

Function Documentation

◆ bootloader_trap_handler()

void bootloader_trap_handler ( void )

Function prototypes

Bootloader trap handler. Used for the MTIME tick and to capture any other traps.

Note: Since we have no runtime environment we have to use the interrupt attribute here.

◆ get_exe()

void get_exe ( int src )

Get executable stream.

Parameters

src	Source of executable stream data. See EXE_STREAM_SOURCE_enum.

◆ get_exe_word()

uint32_t get_exe_word	(	int	src,
		uint32_t	addr )

Get word from executable stream

Parameters

src	Source of executable stream data. See EXE_STREAM_SOURCE_enum.
addr	Address when accessing SPI flash.

Returns: 32-bit data word from stream.

◆ main()

int main ( void )

Sanity check: Base RV32I ISA only! Bootloader main.

◆ print_help()

void print_help ( void )

Print help menu.

◆ print_hex_word()

void print_hex_word ( uint32_t num )

Print 32-bit number as 8-digit hexadecimal value (with "0x" suffix).

Parameters

[in] num Number to print as hexadecimal.

◆ save_exe()

void save_exe ( void )

Store content of instruction memory to SPI flash.

◆ spi_flash_check()

int spi_flash_check ( void )

Check if SPI and flash are available/working by making sure the WEL flag of the flash status register can be set and cleared again.

Returns: 0 if success, -1 if error

◆ spi_flash_erase_sector()

void spi_flash_erase_sector ( uint32_t addr )

Erase sector (64kB) at base address.

Parameters

[in] addr Base address of sector to erase.

◆ spi_flash_read_byte()

uint8_t spi_flash_read_byte ( uint32_t addr )

Read byte from SPI flash.

Parameters

[in] addr Flash read address.

Returns: Read byte from SPI flash.

◆ spi_flash_read_status()

uint8_t spi_flash_read_status ( void )

Read flash status register.

Returns: SPI flash status register (32-bit zero-extended).

◆ spi_flash_wakeup()

void spi_flash_wakeup ( void )

Wake up flash from deep sleep state

◆ spi_flash_write_addr()

void spi_flash_write_addr ( uint32_t addr )

Send address word to flash (MSB-first, 16-bit, 24-bit or 32-bit address size).

Parameters

[in] addr Address word.

◆ spi_flash_write_byte()

void spi_flash_write_byte	(	uint32_t	addr,
		uint8_t	wdata )

Write byte to SPI flash.

Parameters

[in]	addr	SPI flash read address.
[in]	wdata	SPI flash read data.

◆ spi_flash_write_disable()

void spi_flash_write_disable ( void )

Disable flash write access.

◆ spi_flash_write_enable()

void spi_flash_write_enable ( void )

Enable flash write access.

◆ spi_flash_write_word()

void spi_flash_write_word	(	uint32_t	addr,
		uint32_t	wdata )

Write word to SPI flash.

Parameters

addr	SPI flash write address.
wdata	SPI flash write data.

◆ start_app()

void start_app ( int boot_xip )

Start application program.

Parameters

boot_xip Set to boot via XIP.

◆ system_error()

void system_error ( uint8_t err_code )

Output system error ID and halt.

Parameters

[in] err_code Error code. See #ERROR_CODES and error_message.

Variable Documentation

◆ error_message

const char error_message[4][5]

Initial value:

= {
  "EXE",
  "SIZE",
  "CHKS",
  "FLSH"
}

Error messages

◆ exe_available

volatile uint32_t exe_available

This global variable keeps the size of the available executable in bytes. If =0 no executable is available (yet).

◆ getting_exe

volatile uint32_t getting_exe

Only set during executable fetch (required for capturing STORE BUS-TIMOUT exception).

Macros

Enumerations

Functions

Variables

Detailed Description

Macro Definition Documentation

◆ AUTO_BOOT_TIMEOUT

◆ EXE_BASE_ADDR

◆ EXE_SIGNATURE

◆ PRINT_GETC

◆ PRINT_PUTC

◆ PRINT_TEXT

◆ PRINT_XNUM

◆ SPI_BOOT_BASE_ADDR

◆ SPI_EN

◆ SPI_FLASH_ADDR_BYTES

◆ SPI_FLASH_CLK_PRSC

◆ SPI_FLASH_CS

◆ SPI_FLASH_SECTOR_SIZE

◆ STATUS_LED_EN

◆ STATUS_LED_PIN

◆ str

◆ UART_BAUD

◆ UART_EN

◆ UART_HW_HANDSHAKE_EN

◆ XIP_EN

◆ xstr

Enumeration Type Documentation

◆ ERROR_CODES_enum

◆ EXE_STREAM_SOURCE_enum

◆ NEORV32_EXECUTABLE_enum

◆ SPI_FLASH_CMD_enum

◆ SPI_FLASH_SREG_enum

Function Documentation

◆ bootloader_trap_handler()

◆ get_exe()

◆ get_exe_word()

◆ main()

◆ print_help()

◆ print_hex_word()

◆ save_exe()

◆ spi_flash_check()

◆ spi_flash_erase_sector()

◆ spi_flash_read_byte()

◆ spi_flash_read_status()

◆ spi_flash_wakeup()

◆ spi_flash_write_addr()

◆ spi_flash_write_byte()

◆ spi_flash_write_disable()

◆ spi_flash_write_enable()

◆ spi_flash_write_word()

◆ start_app()

◆ system_error()

Variable Documentation

◆ error_message

◆ exe_available

◆ getting_exe