RISC-V: Add early printk support via the SBI console

This code lives entirely within the RISC-V arch code.  I've left it
within an "#ifdef CONFIG_EARLY_PRINTK" despite always having
EARLY_PRINTK support on RISC-V just in case someone wants to remove
it.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
This commit is contained in:
Palmer Dabbelt 2017-12-08 15:10:35 -08:00
parent 758914fea2
commit 5b5c2a2c44
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@ -39,6 +39,27 @@
#include <asm/tlbflush.h>
#include <asm/thread_info.h>
#ifdef CONFIG_EARLY_PRINTK
static void sbi_console_write(struct console *co, const char *buf,
unsigned int n)
{
int i;
for (i = 0; i < n; ++i) {
if (buf[i] == '\n')
sbi_console_putchar('\r');
sbi_console_putchar(buf[i]);
}
}
struct console riscv_sbi_early_console_dev __initdata = {
.name = "early",
.write = sbi_console_write,
.flags = CON_PRINTBUFFER | CON_BOOT | CON_ANYTIME,
.index = -1
};
#endif
#ifdef CONFIG_DUMMY_CONSOLE
struct screen_info screen_info = {
.orig_video_lines = 30,
@ -195,6 +216,12 @@ static void __init setup_bootmem(void)
void __init setup_arch(char **cmdline_p)
{
#if defined(CONFIG_EARLY_PRINTK)
if (likely(early_console == NULL)) {
early_console = &riscv_sbi_early_console_dev;
register_console(early_console);
}
#endif
*cmdline_p = boot_command_line;
parse_early_param();