1 files changed, 64 insertions, 0 deletions
diff --git a/drivers/misc/cbmem_console.c b/drivers/misc/cbmem_console.c
new file mode 100644
index 00000000000..8220addd579
--- /dev/null
+++ b/drivers/misc/cbmem_console.c
@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2011 The ChromiumOS Authors.  All rights reserved.
+ */
+
+#include <console.h>
+#include <linux/string.h>
+#include <asm/cb_sysinfo.h>
+
+void cbmemc_putc(struct stdio_dev *dev, char data)
+{
+	const struct sysinfo_t *sysinfo = cb_get_sysinfo();
+	struct cbmem_console *cons;
+	uint pos, flags;
+
+	if (!sysinfo)
+		return;
+	cons = sysinfo->cbmem_cons;
+	if (!cons)
+		return;
+
+	pos = cons->cursor & CBMC_CURSOR_MASK;
+
+	/* preserve the overflow flag if present */
+	flags = cons->cursor & ~CBMC_CURSOR_MASK;
+
+	cons->body[pos++] = data;
+
+	/*
+	 * Deal with overflow - the flag may be cleared by another program which
+	 * reads the buffer out later, e.g. Linux
+	 */
+	if (pos >= cons->size) {
+		pos = 0;
+		flags |= CBMC_OVERFLOW;
+	}
+
+	cons->cursor = flags | pos;
+}
+
+void cbmemc_puts(struct stdio_dev *dev, const char *str)
+{
+	char c;
+
+	while ((c = *str++) != 0)
+		cbmemc_putc(dev, c);
+}
+
+int cbmemc_init(void)
+{
+	int rc;
+	struct stdio_dev cons_dev;
+
+	memset(&cons_dev, 0, sizeof(cons_dev));
+
+	strcpy(cons_dev.name, "cbmem");
+	cons_dev.flags = DEV_FLAGS_OUTPUT; /* Output only */
+	cons_dev.putc  = cbmemc_putc;
+	cons_dev.puts  = cbmemc_puts;
+
+	rc = stdio_register(&cons_dev);
+
+	return (rc == 0) ? 1 : rc;
+}