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-rw-r--r--arch/blackfin/Kconfig14
-rw-r--r--arch/blackfin/kernel/Makefile1
-rw-r--r--arch/blackfin/kernel/early_printk.c161
3 files changed, 176 insertions, 0 deletions
diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig
index 26ebb0e8c431..cc789b988f3a 100644
--- a/arch/blackfin/Kconfig
+++ b/arch/blackfin/Kconfig
@@ -1164,6 +1164,20 @@ config DEBUG_BFIN_NO_KERN_HWTRACE
Say Y here to disable hardware tracing in some known "jumpy" pieces
of code so that the trace buffer will extend further back.
+config EARLY_PRINTK
+ bool "Early printk"
+ default n
+ help
+ This option enables special console drivers which allow the kernel
+ to print messages very early in the bootup process.
+
+ This is useful for kernel debugging when your machine crashes very
+ early before the console code is initialized. After enabling this
+ feature, you must add "earlyprintk=serial,uart0,57600" to the
+ command line (bootargs). It is safe to say Y here in all cases, as
+ all of this lives in the init section and is thrown away after the
+ kernel boots completely.
+
config DUAL_CORE_TEST_MODULE
tristate "Dual Core Test Module"
depends on (BF561)
diff --git a/arch/blackfin/kernel/Makefile b/arch/blackfin/kernel/Makefile
index 243883ec6de1..8aeb6066b19b 100644
--- a/arch/blackfin/kernel/Makefile
+++ b/arch/blackfin/kernel/Makefile
@@ -13,3 +13,4 @@ obj-$(CONFIG_MODULES) += module.o
obj-$(CONFIG_BFIN_DMA_5XX) += bfin_dma_5xx.o
obj-$(CONFIG_DUAL_CORE_TEST_MODULE) += dualcore_test.o
obj-$(CONFIG_KGDB) += kgdb.o
+obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
diff --git a/arch/blackfin/kernel/early_printk.c b/arch/blackfin/kernel/early_printk.c
new file mode 100644
index 000000000000..9bf61706694f
--- /dev/null
+++ b/arch/blackfin/kernel/early_printk.c
@@ -0,0 +1,161 @@
+/*
+ * File: arch/blackfin/kernel/early_printk.c
+ * Based on: arch/x86_64/kernel/early_printk.c
+ * Author: Robin Getz <rgetz@blackfin.uclinux.org
+ *
+ * Created: 14Aug2007
+ * Description: allow a console to be used for early printk
+ *
+ * Modified:
+ * Copyright 2004-2007 Analog Devices Inc.
+ *
+ * Bugs: Enter bugs at http://blackfin.uclinux.org/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/serial_core.h>
+#include <linux/console.h>
+#include <linux/string.h>
+#include <asm/blackfin.h>
+#include <asm/irq_handler.h>
+#include <asm/early_printk.h>
+
+#ifdef CONFIG_SERIAL_BFIN
+extern struct console *bfin_earlyserial_init(unsigned int port,
+ unsigned int cflag);
+#endif
+
+static struct console *early_console;
+
+/* Default console
+ * Port n == ttyBFn
+ * cflags == UART output modes
+ */
+#define DEFAULT_PORT 0
+#define DEFAULT_CFLAG CS8|B57600
+
+#ifdef CONFIG_SERIAL_CORE
+/* What should get here is "0,57600" */
+static struct console * __init earlyserial_init(char *buf)
+{
+ int baud, bit;
+ char parity;
+ unsigned int serial_port = DEFAULT_PORT;
+ unsigned int cflag = DEFAULT_CFLAG;
+
+ serial_port = simple_strtoul(buf, &buf, 10);
+ buf++;
+
+ cflag = 0;
+ baud = simple_strtoul(buf, &buf, 10);
+ switch (baud) {
+ case 1200:
+ cflag |= B1200;
+ break;
+ case 2400:
+ cflag |= B2400;
+ break;
+ case 4800:
+ cflag |= B4800;
+ break;
+ case 9600:
+ cflag |= B9600;
+ break;
+ case 19200:
+ cflag |= B19200;
+ break;
+ case 38400:
+ cflag |= B38400;
+ break;
+ case 115200:
+ cflag |= B115200;
+ break;
+ default:
+ cflag |= B57600;
+ }
+
+ parity = buf[0];
+ buf++;
+ switch (parity) {
+ case 'e':
+ cflag |= PARENB;
+ break;
+ case 'o':
+ cflag |= PARODD;
+ break;
+ }
+
+ bit = simple_strtoul(buf, &buf, 10);
+ switch (bit) {
+ case 5:
+ cflag |= CS5;
+ break;
+ case 6:
+ cflag |= CS5;
+ break;
+ case 7:
+ cflag |= CS5;
+ break;
+ default:
+ cflag |= CS8;
+ }
+
+#ifdef CONFIG_SERIAL_BFIN
+ return bfin_earlyserial_init(serial_port, cflag);
+#else
+ return NULL;
+#endif
+
+}
+#endif
+
+int __init setup_early_printk(char *buf)
+{
+
+ /* Crashing in here would be really bad, so check both the var
+ and the pointer before we start using it
+ */
+ if (!buf)
+ return 0;
+
+ if (!*buf)
+ return 0;
+
+ if (early_console != NULL)
+ return 0;
+
+#ifdef CONFIG_SERIAL_BFIN
+ /* Check for Blackfin Serial */
+ if (!strncmp(buf, "serial,uart", 11)) {
+ buf += 11;
+ early_console = earlyserial_init(buf);
+ }
+#endif
+#ifdef CONFIG_FB
+ /* TODO: add framebuffer console support */
+#endif
+
+ if (likely(early_console)) {
+ early_console->flags |= CON_BOOT;
+
+ register_console(early_console);
+ printk(KERN_INFO "early printk enabled on %s%d\n",
+ early_console->name,
+ early_console->index);
+ }
+
+ return 0;
+}
+
+early_param("earlyprintk", setup_early_printk);