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authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/drivers/tty/serial/earlycon-arm-semihost.c
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/drivers/tty/serial/earlycon-arm-semihost.c')
-rw-r--r--kernel/drivers/tty/serial/earlycon-arm-semihost.c61
1 files changed, 61 insertions, 0 deletions
diff --git a/kernel/drivers/tty/serial/earlycon-arm-semihost.c b/kernel/drivers/tty/serial/earlycon-arm-semihost.c
new file mode 100644
index 000000000..383db10fb
--- /dev/null
+++ b/kernel/drivers/tty/serial/earlycon-arm-semihost.c
@@ -0,0 +1,61 @@
+/*
+ * Copyright (C) 2012 ARM Ltd.
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ *
+ * Adapted for ARM and earlycon:
+ * Copyright (C) 2014 Linaro Ltd.
+ * Author: Rob Herring <robh@kernel.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <linux/kernel.h>
+#include <linux/console.h>
+#include <linux/init.h>
+#include <linux/serial_core.h>
+
+#ifdef CONFIG_THUMB2_KERNEL
+#define SEMIHOST_SWI "0xab"
+#else
+#define SEMIHOST_SWI "0x123456"
+#endif
+
+/*
+ * Semihosting-based debug console
+ */
+static void smh_putc(struct uart_port *port, int c)
+{
+#ifdef CONFIG_ARM64
+ asm volatile("mov x1, %0\n"
+ "mov x0, #3\n"
+ "hlt 0xf000\n"
+ : : "r" (&c) : "x0", "x1", "memory");
+#else
+ asm volatile("mov r1, %0\n"
+ "mov r0, #3\n"
+ "svc " SEMIHOST_SWI "\n"
+ : : "r" (&c) : "r0", "r1", "memory");
+#endif
+}
+
+static void smh_write(struct console *con, const char *s, unsigned n)
+{
+ struct earlycon_device *dev = con->data;
+ uart_console_write(&dev->port, s, n, smh_putc);
+}
+
+int __init early_smh_setup(struct earlycon_device *device, const char *opt)
+{
+ device->con->write = smh_write;
+ return 0;
+}
+EARLYCON_DECLARE(smh, early_smh_setup);