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authorPalmer Dabbelt <palmer@sifive.com>2017-12-08 15:10:35 -0800
committerPalmer Dabbelt <palmer@sifive.com>2018-08-13 08:31:30 -0700
commit5b5c2a2c44d7225ab3abbcc7e1881b97ea9872dd (patch)
treeea7f911326a319e74058cfb5b30ad3f5b2d90fee /arch/riscv/kernel
parent758914fea278658943e3a56e4d373ae8c6f0d9e5 (diff)
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>
Diffstat (limited to 'arch/riscv/kernel')
-rw-r--r--arch/riscv/kernel/setup.c27
1 files changed, 27 insertions, 0 deletions
diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index f0d2070866d4..db20dc630e7e 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -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();