From: Octavian Purdila <tavi.purdila@xxxxxxxxx>
This patch adds a basic structure of console support in kernel. Write
operations are deferred to the host print operation.
Signed-off-by: Octavian Purdila <tavi.purdila@xxxxxxxxx>
---
arch/um/lkl/include/uapi/asm/host_ops.h | 4 +++
arch/um/lkl/kernel/console.c | 42 +++++++++++++++++++++++++
2 files changed, 46 insertions(+)
create mode 100644 arch/um/lkl/kernel/console.c
diff --git a/arch/um/lkl/include/uapi/asm/host_ops.h b/arch/um/lkl/include/uapi/asm/host_ops.h
index c9f77dd7fbe7..986340ba9d8d 100644
--- a/arch/um/lkl/include/uapi/asm/host_ops.h
+++ b/arch/um/lkl/include/uapi/asm/host_ops.h
@@ -17,6 +17,8 @@ struct lkl_jmp_buf {
* These operations must be provided by a host library or by the application
* itself.
*
+ * @print - optional operation that receives console messages
+ *
* @sem_alloc - allocate a host semaphore an initialize it to count
* @sem_free - free a host semaphore
* @sem_up - perform an up operation on the semaphore
@@ -70,6 +72,8 @@ struct lkl_jmp_buf {
* @jmp_buf_longjmp - perform a jump back to the saved jump buffer
*/
struct lkl_host_operations {
+ void (*print)(const char *str, int len);
+
struct lkl_sem *(*sem_alloc)(int count);
void (*sem_free)(struct lkl_sem *sem);
void (*sem_up)(struct lkl_sem *sem);
diff --git a/arch/um/lkl/kernel/console.c b/arch/um/lkl/kernel/console.c
new file mode 100644
index 000000000000..54d7f756c6da
--- /dev/null
+++ b/arch/um/lkl/kernel/console.c
@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/console.h>
+#include <asm/host_ops.h>
+
+static void console_write(struct console *con, const char *str,
+ unsigned int len)
+{
+ if (lkl_ops->print)
+ lkl_ops->print(str, len);
+}
+
+#ifdef CONFIG_LKL_EARLY_CONSOLE
+static struct console lkl_boot_console = {
+ .name = "lkl_boot_console",
+ .write = console_write,
+ .flags = CON_PRINTBUFFER | CON_BOOT,
+ .index = -1,
+};
+
+int __init lkl_boot_console_init(void)
+{
+ register_console(&lkl_boot_console);
+ return 0;
+}
+early_initcall(lkl_boot_console_init);
+#endif
+
+static struct console lkl_console = {
+ .name = "lkl_console",
+ .write = console_write,
+ .flags = CON_PRINTBUFFER,
+ .index = -1,
+};
+
+static int __init lkl_console_init(void)
+{
+ register_console(&lkl_console);
+ return 0;
+}
+core_initcall(lkl_console_init);
--
2.21.0 (Apple Git-122.2)
