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157 lines
3.2 KiB
C
157 lines
3.2 KiB
C
#include <unistd.h>
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#include <string.h>
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#include <stdint.h>
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#include <stdbool.h>
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#include <stdarg.h>
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#include <stdio.h>
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#include <generated/git.h>
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#include "microwatt_soc.h"
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#include "io.h"
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#include "sdram.h"
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/*
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* Core UART functions to implement for a port
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*/
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static uint64_t potato_uart_base;
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#define PROC_FREQ 100000000
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#define UART_FREQ 115200
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static uint8_t potato_uart_reg_read(int offset)
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{
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return readb(potato_uart_base + offset);
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}
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static void potato_uart_reg_write(int offset, uint8_t val)
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{
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writeb(val, potato_uart_base + offset);
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}
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static bool potato_uart_rx_empty(void)
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{
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uint8_t val = potato_uart_reg_read(POTATO_CONSOLE_STATUS);
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return (val & POTATO_CONSOLE_STATUS_RX_EMPTY) != 0;
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}
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static int potato_uart_tx_full(void)
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{
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uint8_t val = potato_uart_reg_read(POTATO_CONSOLE_STATUS);
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return (val & POTATO_CONSOLE_STATUS_TX_FULL) != 0;
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}
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static char potato_uart_read(void)
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{
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return potato_uart_reg_read(POTATO_CONSOLE_RX);
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}
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static void potato_uart_write(char c)
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{
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potato_uart_reg_write(POTATO_CONSOLE_TX, c);
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}
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static unsigned long potato_uart_divisor(unsigned long proc_freq,
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unsigned long uart_freq)
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{
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return proc_freq / (uart_freq * 16) - 1;
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}
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void potato_uart_init(void)
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{
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potato_uart_base = UART_BASE;
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potato_uart_reg_write(POTATO_CONSOLE_CLOCK_DIV,
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potato_uart_divisor(PROC_FREQ, UART_FREQ));
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}
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int getchar(void)
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{
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while (potato_uart_rx_empty())
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/* Do nothing */ ;
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return potato_uart_read();
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}
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int putchar(int c)
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{
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while (potato_uart_tx_full())
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/* Do Nothing */;
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potato_uart_write(c);
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return c;
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}
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void putstr(const char *str, unsigned long len)
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{
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for (unsigned long i = 0; i < len; i++) {
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if (str[i] == '\n')
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putchar('\r');
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putchar(str[i]);
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}
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}
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int _printf(const char *fmt, ...)
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{
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int count;
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char buffer[320];
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va_list ap;
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va_start(ap, fmt);
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count = vsnprintf(buffer, sizeof(buffer), fmt, ap);
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va_end(ap);
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putstr(buffer, count);
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return count;
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}
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void flush_cpu_dcache(void) { }
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void flush_cpu_icache(void) { }
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void flush_l2_cache(void) { }
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void main(void)
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{
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unsigned long long ftr, val;
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int i;
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/*
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* Let things settle ... not sure why but the UART is
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* not happy otherwise. The PLL might need to settle ?
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*/
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potato_uart_init();
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for (i = 0; i < 100000; i++)
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potato_uart_reg_read(POTATO_CONSOLE_STATUS);
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printf("\n\nWelcome to Microwatt !\n\n");
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/* TODO: Add core version information somewhere in syscon, possibly
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* extracted from git
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*/
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printf(" Soc signature: %016llx\n",
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(unsigned long long)readq(SYSCON_BASE + SYS_REG_SIGNATURE));
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printf(" Soc features: ");
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ftr = readq(SYSCON_BASE + SYS_REG_INFO);
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if (ftr & SYS_REG_INFO_HAS_UART)
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printf("UART ");
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if (ftr & SYS_REG_INFO_HAS_DRAM)
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printf("DRAM ");
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printf("\n");
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val = readq(SYSCON_BASE + SYS_REG_BRAMINFO);
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printf(" BRAM: %lld KB\n", val / 1024);
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if (ftr & SYS_REG_INFO_HAS_DRAM) {
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val = readq(SYSCON_BASE + SYS_REG_DRAMINFO);
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printf(" DRAM: %lld MB\n", val / (1024 * 1024));
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}
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val = readq(SYSCON_BASE + SYS_REG_CLKINFO);
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printf(" CLK: %lld MHz\n", val / 1000000);
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printf("\n");
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if (ftr & SYS_REG_INFO_HAS_DRAM) {
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printf("LiteDRAM built from Migen %s and LiteX %s\n",
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MIGEN_GIT_SHA1, LITEX_GIT_SHA1);
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sdrinit();
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}
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printf("Booting from BRAM...\n");
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}
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