#include <linux/console.h>
#include <linux/io.h>
#include <mach/mt_reg_base.h>
#define UART_BASE UART1_BASE /* 根据需要修改，比如有些平台是AP_UART0_BASE */
#define EARLY_BASE (VMALLOC_START - SZ_1M)
static void mtuart_printch(char ch)
{
while (!(readl_relaxed((void __iomem *)EARLY_BASE + 0x14)&0x20));
writel_relaxed(ch, (void __iomem *)EARLY_BASE);
}
static void early_write(struct console *con, const char *s, unsigned n)
{
while (n-- > 0) {
if (*s == '\n')
mtuart_printch('\r');
mtuart_printch(*s);
s++;
}
}
static void __init setup_early_printk(void)
{
static struct console early_console_dev = {
.name = "earlycon",
.write = early_write,
.flags = CON_PRINTBUFFER|CON_BOOT,
.index = -1,
};
struct map_desc mt_uart_desc = {
.virtual = EARLY_BASE,
.pfn = __phys_to_pfn(IO_VIRT_TO_PHYS(UART_BASE)),
.length = SZ_4K,
.type = MT_DEVICE,
};
create_mapping(&mt_uart_desc, false);
register_console(&early_console_dev);
}
