risc-v: implement DBCN write byte
The DBCN extension provides a Console Write Byte call.
Implement function sbi_dbcn_write_byte to invoke it.
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Leo Yu-Chi Liang <ycliang@andestech.com>
diff --git a/arch/riscv/lib/sbi.c b/arch/riscv/lib/sbi.c
index 8724e3a..55a3bc3 100644
--- a/arch/riscv/lib/sbi.c
+++ b/arch/riscv/lib/sbi.c
@@ -204,6 +204,22 @@
0, 0, 0, 0);
}
+/**
+ * sbi_dbcn_write_byte() - write byte to debug console
+ *
+ * @ch: byte to be written
+ * Return: SBI error code (SBI_SUCCESS = 0 on success)
+ */
+int sbi_dbcn_write_byte(unsigned char ch)
+{
+ struct sbiret ret;
+
+ ret = sbi_ecall(SBI_EXT_DBCN,
+ SBI_EXT_DBCN_CONSOLE_WRITE_BYTE,
+ ch, 0, 0, 0, 0, 0);
+ return ret.error;
+}
+
#ifdef CONFIG_SBI_V01
/**