You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
164 lines
3.6 KiB
C
164 lines
3.6 KiB
C
#include <unistd.h>
|
|
#include <string.h>
|
|
#include <stdint.h>
|
|
#include <stdbool.h>
|
|
#include <stdarg.h>
|
|
#include <stdio.h>
|
|
|
|
#include "sdram.h"
|
|
|
|
/*
|
|
* Core UART functions to implement for a port
|
|
*/
|
|
|
|
static uint64_t potato_uart_base;
|
|
|
|
#define PROC_FREQ 100000000
|
|
#define UART_FREQ 115200
|
|
#define UART_BASE 0xc0002000
|
|
#define SYSCON_BASE 0xc0000000
|
|
|
|
#define POTATO_CONSOLE_TX 0x00
|
|
#define POTATO_CONSOLE_RX 0x08
|
|
#define POTATO_CONSOLE_STATUS 0x10
|
|
#define POTATO_CONSOLE_STATUS_RX_EMPTY 0x01
|
|
#define POTATO_CONSOLE_STATUS_TX_EMPTY 0x02
|
|
#define POTATO_CONSOLE_STATUS_RX_FULL 0x04
|
|
#define POTATO_CONSOLE_STATUS_TX_FULL 0x08
|
|
#define POTATO_CONSOLE_CLOCK_DIV 0x18
|
|
#define POTATO_CONSOLE_IRQ_EN 0x20
|
|
|
|
static inline uint8_t readb(unsigned long addr)
|
|
{
|
|
__asm__ volatile("sync" : : : "memory");
|
|
return *((volatile uint8_t *)addr);
|
|
}
|
|
|
|
static inline uint64_t readq(unsigned long addr)
|
|
{
|
|
__asm__ volatile("sync" : : : "memory");
|
|
return *((volatile uint64_t *)addr);
|
|
}
|
|
|
|
static inline void writeb(uint8_t val, unsigned long addr)
|
|
{
|
|
__asm__ volatile("sync" : : : "memory");
|
|
*((volatile uint8_t *)addr) = val;
|
|
}
|
|
|
|
static inline void writeq(uint64_t val, unsigned long addr)
|
|
{
|
|
__asm__ volatile("sync" : : : "memory");
|
|
*((volatile uint64_t *)addr) = val;
|
|
}
|
|
|
|
static uint8_t potato_uart_reg_read(int offset)
|
|
{
|
|
return readb(potato_uart_base + offset);
|
|
}
|
|
|
|
static void potato_uart_reg_write(int offset, uint8_t val)
|
|
{
|
|
writeb(val, potato_uart_base + offset);
|
|
}
|
|
|
|
static bool potato_uart_rx_empty(void)
|
|
{
|
|
uint8_t val = potato_uart_reg_read(POTATO_CONSOLE_STATUS);
|
|
|
|
return (val & POTATO_CONSOLE_STATUS_RX_EMPTY) != 0;
|
|
}
|
|
|
|
static int potato_uart_tx_full(void)
|
|
{
|
|
uint8_t val = potato_uart_reg_read(POTATO_CONSOLE_STATUS);
|
|
|
|
return (val & POTATO_CONSOLE_STATUS_TX_FULL) != 0;
|
|
}
|
|
|
|
static char potato_uart_read(void)
|
|
{
|
|
return potato_uart_reg_read(POTATO_CONSOLE_RX);
|
|
}
|
|
|
|
static void potato_uart_write(char c)
|
|
{
|
|
potato_uart_reg_write(POTATO_CONSOLE_TX, c);
|
|
}
|
|
|
|
static unsigned long potato_uart_divisor(unsigned long proc_freq,
|
|
unsigned long uart_freq)
|
|
{
|
|
return proc_freq / (uart_freq * 16) - 1;
|
|
}
|
|
|
|
void potato_uart_init(void)
|
|
{
|
|
potato_uart_base = UART_BASE;
|
|
|
|
potato_uart_reg_write(POTATO_CONSOLE_CLOCK_DIV,
|
|
potato_uart_divisor(PROC_FREQ, UART_FREQ));
|
|
}
|
|
|
|
int getchar(void)
|
|
{
|
|
while (potato_uart_rx_empty())
|
|
/* Do nothing */ ;
|
|
|
|
return potato_uart_read();
|
|
}
|
|
|
|
int putchar(int c)
|
|
{
|
|
while (potato_uart_tx_full())
|
|
/* Do Nothing */;
|
|
|
|
potato_uart_write(c);
|
|
return c;
|
|
}
|
|
|
|
void putstr(const char *str, unsigned long len)
|
|
{
|
|
for (unsigned long i = 0; i < len; i++) {
|
|
if (str[i] == '\n')
|
|
putchar('\r');
|
|
putchar(str[i]);
|
|
}
|
|
}
|
|
|
|
int _printf(const char *fmt, ...)
|
|
{
|
|
int count;
|
|
char buffer[320];
|
|
va_list ap;
|
|
|
|
va_start(ap, fmt);
|
|
count = vsnprintf(buffer, sizeof(buffer), fmt, ap);
|
|
va_end(ap);
|
|
putstr(buffer, count);
|
|
return count;
|
|
}
|
|
|
|
void flush_cpu_dcache(void) { }
|
|
void flush_cpu_icache(void) { }
|
|
void flush_l2_cache(void) { }
|
|
|
|
void main(void)
|
|
{
|
|
int i;
|
|
|
|
// Let things settle ... not sure why but UART not happy otherwise
|
|
potato_uart_init();
|
|
for (i = 0; i < 10000; i++)
|
|
potato_uart_reg_read(POTATO_CONSOLE_STATUS);
|
|
printf("Welcome to Microwatt !\n");
|
|
printf(" SIG: %016llx\n", (unsigned long long)readq(SYSCON_BASE + 0x00));
|
|
printf(" INFO: %016llx\n", (unsigned long long)readq(SYSCON_BASE + 0x08));
|
|
printf(" BRAMINFO: %016llx\n", (unsigned long long)readq(SYSCON_BASE + 0x10));
|
|
printf(" DRAMINFO: %016llx\n", (unsigned long long)readq(SYSCON_BASE + 0x18));
|
|
printf(" CLKINFO: %016llx\n", (unsigned long long)readq(SYSCON_BASE + 0x20));
|
|
printf(" CTRL: %016llx\n", (unsigned long long)readq(SYSCON_BASE + 0x28));
|
|
sdrinit();
|
|
printf("Booting from BRAM...\n");
|
|
}
|