Title: [6928] branches/2009R1/arch/blackfin: Add a "shadow_console", which is a console keeps a copy of the
- Revision
- 6928
- Author
- rgetz
- Date
- 2009-07-06 10:03:35 -0500 (Mon, 06 Jul 2009)
Log Message
Add a "shadow_console", which is a console keeps a copy of the
printk buffer in a predefined portion of memory, which U-Boot can print
out if it thinks there has been an error during boot.
Modified Paths
Added Paths
Diff
Modified: branches/2009R1/arch/blackfin/include/asm/early_printk.h (6927 => 6928)
--- branches/2009R1/arch/blackfin/include/asm/early_printk.h 2009-07-06 14:53:19 UTC (rev 6927)
+++ branches/2009R1/arch/blackfin/include/asm/early_printk.h 2009-07-06 15:03:35 UTC (rev 6928)
@@ -23,6 +23,8 @@
#ifdef CONFIG_EARLY_PRINTK
extern int setup_early_printk(char *);
+extern void enable_shadow_console(void);
#else
#define setup_early_printk(fmt) do { } while (0)
+#define enable_shadow_console(fmt) do { } while (0)
#endif /* CONFIG_EARLY_PRINTK */
Modified: branches/2009R1/arch/blackfin/kernel/Makefile (6927 => 6928)
--- branches/2009R1/arch/blackfin/kernel/Makefile 2009-07-06 14:53:19 UTC (rev 6927)
+++ branches/2009R1/arch/blackfin/kernel/Makefile 2009-07-06 15:03:35 UTC (rev 6928)
@@ -23,6 +23,7 @@
obj-$(CONFIG_KGDB) += kgdb.o
obj-$(CONFIG_KGDB_TESTS) += kgdb_test.o
obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
+obj-$(CONFIG_EARLY_PRINTK) += shadow_console.o
obj-$(CONFIG_DEBUG_MMRS) += debug-mmrs.o
# the kgdb test puts code into L2 and without linker
Modified: branches/2009R1/arch/blackfin/kernel/setup.c (6927 => 6928)
--- branches/2009R1/arch/blackfin/kernel/setup.c 2009-07-06 14:53:19 UTC (rev 6927)
+++ branches/2009R1/arch/blackfin/kernel/setup.c 2009-07-06 15:03:35 UTC (rev 6928)
@@ -770,6 +770,8 @@
{
unsigned long sclk, cclk;
+ enable_shadow_console();
+
#ifdef CONFIG_DUMMY_CONSOLE
conswitchp = &dummy_con;
#endif
Added: branches/2009R1/arch/blackfin/kernel/shadow_console.c (0 => 6928)
--- branches/2009R1/arch/blackfin/kernel/shadow_console.c (rev 0)
+++ branches/2009R1/arch/blackfin/kernel/shadow_console.c 2009-07-06 15:03:35 UTC (rev 6928)
@@ -0,0 +1,90 @@
+/*
+ * File: arch/blackfin/kernel/early_printk.c
+ * Author: Robin Getz <[email protected]
+ *
+ * Created: 03Jul2009
+ * Description: creates a shadow of the __log_buf, which is printed by the
+ * bootloader if things panic during init
+ *
+ * Copyright 2009 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/console.h>
+#include <linux/string.h>
+#include <asm/blackfin.h>
+#include <asm/irq_handler.h>
+#include <asm/early_printk.h>
+
+#define SHADOW_CONSOLE_START (0x500)
+#define SHADOW_CONSOLE_END (0x1000)
+#define SHADOW_CONSOLE_MAGIC_LOC (0x4F0)
+#define SHADOW_CONSOLE_MAGIC (0xDEADBEEF)
+
+static __initdata char *shadow_console_buffer = (char *)SHADOW_CONSOLE_START;
+
+static __init void early_shadow_write(struct console *con, const char *s,
+ unsigned int n)
+{
+ /*
+ * save 2 bytes for the double null at the end
+ * once we fail on a long line, make sure we don't write a short line afterwards
+ */
+ if ((shadow_console_buffer + n) <= (char *)(SHADOW_CONSOLE_END - 2)) {
+ memcpy(shadow_console_buffer, s, n);
+ shadow_console_buffer += n;
+ shadow_console_buffer[0] = 0;
+ shadow_console_buffer[1] = 0;
+ } else
+ shadow_console_buffer = (char *)SHADOW_CONSOLE_END;
+}
+
+static __initdata struct console early_shadow_console = {
+ .name = "early_shadow",
+ .write = early_shadow_write,
+ .flags = CON_BOOT | CON_PRINTBUFFER,
+ .index = -1,
+ .device = 0,
+};
+
+__init void enable_shadow_console(void)
+{
+ int *loc = (int *)SHADOW_CONSOLE_MAGIC_LOC;
+
+ if (!(early_shadow_console.flags & CON_ENABLED)) {
+ register_console(&early_shadow_console);
+ /* for now, assume things are going to fail */
+ *loc = SHADOW_CONSOLE_MAGIC;
+ loc++;
+ *loc = SHADOW_CONSOLE_START;
+ }
+}
+
+static __init int disable_shadow_console(void)
+{
+ /*
+ * by the time pure_initcall runs, the standard console is enabled,
+ * and the early_console is off, so unset the magic numbers
+ * unregistering the console is taken care of in common code (See
+ * ./kernel/printk:disable_boot_consoles() )
+ */
+ int *loc = (int *)SHADOW_CONSOLE_MAGIC_LOC;
+
+ *loc = 0;
+
+ return 0;
+}
+pure_initcall(disable_shadow_console);
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