[PATCH dovetail v12 01/11] riscv: introduce raw console device

Tobias Schaffner <[email protected]> Tue, 28 Jul 2026 13:12:12 +0200
Newsgroups dev.linux.lists.xenomai
Message-ID <[email protected]>
Signed-off-by: Tobias Schaffner <[email protected]>
---
 arch/riscv/kernel/Makefile     |  1 +
 arch/riscv/kernel/raw_printk.c | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+)
 create mode 100644 arch/riscv/kernel/raw_printk.c

diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
index cabb99cadfb6..4e310257499a 100644
--- a/arch/riscv/kernel/Makefile
+++ b/arch/riscv/kernel/Makefile
@@ -104,6 +104,7 @@ obj-$(CONFIG_RISCV_SBI)		+= sbi.o sbi_ecall.o
 ifeq ($(CONFIG_RISCV_SBI), y)
 obj-$(CONFIG_SMP)		+= sbi-ipi.o
 obj-$(CONFIG_SMP) += cpu_ops_sbi.o
+obj-$(CONFIG_RAW_PRINTK)	+= raw_printk.o
 endif
 obj-$(CONFIG_HOTPLUG_CPU)	+= cpu-hotplug.o
 obj-$(CONFIG_PARAVIRT)		+= paravirt.o
diff --git a/arch/riscv/kernel/raw_printk.c b/arch/riscv/kernel/raw_printk.c
new file mode 100644
index 000000000000..aa2f287daa29
--- /dev/null
+++ b/arch/riscv/kernel/raw_printk.c
@@ -0,0 +1,33 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Raw console device for RISC-V using SBI debug console (DBCN).
+ *
+ * Copyright (C) 2026 Siemens AG
+ * Author:       Tobias Schaffner <[email protected]>.
+ */
+
+#include <linux/kernel.h>
+#include <linux/console.h>
+#include <linux/init.h>
+#include <asm/sbi.h>
+
+static void raw_console_write(struct console *co,
+			      const char *s, unsigned int count)
+{
+	sbi_debug_console_write(s, count);
+}
+
+static struct console raw_console = {
+	.name		= "rawcon",
+	.write_raw	= raw_console_write,
+	.flags		= CON_PRINTBUFFER | CON_ENABLED,
+	.index		= -1,
+};
+
+static int __init raw_console_init(void)
+{
+	register_console(&raw_console);
+
+	return 0;
+}
+console_initcall(raw_console_init);
-- 
2.43.0