MIPS: ralink: add a bootrom dumper module

This patch adds a trivial driver that allows userland to extract the bootrom of
a SoC via debugfs.

Signed-off-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/8002/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

diff --git a/arch/mips/ralink/Makefile b/arch/mips/ralink/Makefile
index 833fa67..a6c9d00 100644 (file)
--- a/arch/mips/ralink/Makefile
+++ b/arch/mips/ralink/Makefile
@@ -18,3 +18,5 @@ obj-$(CONFIG_SOC_RT3883) += rt3883.o
 obj-$(CONFIG_SOC_MT7620) += mt7620.o
 
 obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
+
+obj-$(CONFIG_DEBUG_FS) += bootrom.o

diff --git a/arch/mips/ralink/bootrom.c b/arch/mips/ralink/bootrom.c
new file mode 100644 (file)
index 0000000..5403468
--- /dev/null
+++ b/arch/mips/ralink/bootrom.c
@@ -0,0 +1,48 @@
+/*
+ * 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.
+ *
+ * Copyright (C) 2013 John Crispin <blogic@openwrt.org>
+ */
+
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+
+#define BOOTROM_OFFSET 0x10118000
+#define BOOTROM_SIZE   0x8000
+
+static void __iomem *membase = (void __iomem *) KSEG1ADDR(BOOTROM_OFFSET);
+
+static int bootrom_show(struct seq_file *s, void *unused)
+{
+       seq_write(s, membase, BOOTROM_SIZE);
+
+       return 0;
+}
+
+static int bootrom_open(struct inode *inode, struct file *file)
+{
+       return single_open(file, bootrom_show, NULL);
+}
+
+static const struct file_operations bootrom_file_ops = {
+       .open           = bootrom_open,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = single_release,
+};
+
+static int bootrom_setup(void)
+{
+       if (!debugfs_create_file("bootrom", 0444,
+                       NULL, NULL, &bootrom_file_ops)) {
+               pr_err("Failed to create bootrom debugfs file\n");
+
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+postcore_initcall(bootrom_setup);