From aa5ac789bd96c7a6628a8167de562fa660f1f481 Mon Sep 17 00:00:00 2001
From: Greg Ungerer <gerg@linux-m68k.org>
Date: Mon, 5 Sep 2016 15:23:50 +1000
Subject: m68k: generalize uboot command line support

The uboot command line support needs to be used by both MMU and no-MMU
setups, but currently we only have the code in the no-MMU code paths.
Move the uboot command line processing code into its own file. Add
appropriate calls to it from both the MMU and no-MMU arch setup code.

Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
---
 arch/m68k/kernel/uboot.c | 107 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 107 insertions(+)
 create mode 100644 arch/m68k/kernel/uboot.c

(limited to 'arch/m68k/kernel/uboot.c')

diff --git a/arch/m68k/kernel/uboot.c b/arch/m68k/kernel/uboot.c
new file mode 100644
index 000000000000..b3536a82a262
--- /dev/null
+++ b/arch/m68k/kernel/uboot.c
@@ -0,0 +1,107 @@
+/*
+ * uboot.c -- uboot arguments support
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/fb.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/console.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/bootmem.h>
+#include <linux/seq_file.h>
+#include <linux/init.h>
+#include <linux/initrd.h>
+#include <linux/root_dev.h>
+#include <linux/rtc.h>
+
+#include <asm/setup.h>
+#include <asm/irq.h>
+#include <asm/machdep.h>
+#include <asm/pgtable.h>
+#include <asm/sections.h>
+
+/*
+ * parse_uboot_commandline
+ *
+ * Copies u-boot commandline arguments and store them in the proper linux
+ * variables.
+ *
+ * Assumes:
+ *	_init_sp global contains the address in the stack pointer when the
+ *	kernel starts (see head.S::_start)
+ *
+ *	U-Boot calling convention:
+ *	(*kernel) (kbd, initrd_start, initrd_end, cmd_start, cmd_end);
+ *
+ *	_init_sp can be parsed as such
+ *
+ *	_init_sp+00 = u-boot cmd after jsr into kernel (skip)
+ *	_init_sp+04 = &kernel board_info (residual data)
+ *	_init_sp+08 = &initrd_start
+ *	_init_sp+12 = &initrd_end
+ *	_init_sp+16 = &cmd_start
+ *	_init_sp+20 = &cmd_end
+ *
+ *	This also assumes that the memory locations pointed to are still
+ *	unmodified. U-boot places them near the end of external SDRAM.
+ *
+ * Argument(s):
+ *	commandp = the linux commandline arg container to fill.
+ *	size     = the sizeof commandp.
+ *
+ * Returns:
+ */
+static void __init parse_uboot_commandline(char *commandp, int size)
+{
+	extern unsigned long _init_sp;
+	unsigned long *sp;
+	unsigned long uboot_kbd;
+	unsigned long uboot_initrd_start, uboot_initrd_end;
+	unsigned long uboot_cmd_start, uboot_cmd_end;
+
+	sp = (unsigned long *)_init_sp;
+	uboot_kbd = sp[1];
+	uboot_initrd_start = sp[2];
+	uboot_initrd_end = sp[3];
+	uboot_cmd_start = sp[4];
+	uboot_cmd_end = sp[5];
+
+	if (uboot_cmd_start && uboot_cmd_end)
+		strncpy(commandp, (const char *)uboot_cmd_start, size);
+#if defined(CONFIG_BLK_DEV_INITRD)
+	if (uboot_initrd_start && uboot_initrd_end &&
+	    (uboot_initrd_end > uboot_initrd_start)) {
+		initrd_start = uboot_initrd_start;
+		initrd_end = uboot_initrd_end;
+		ROOT_DEV = Root_RAM0;
+		printk(KERN_INFO "initrd at 0x%lx:0x%lx\n",
+			initrd_start, initrd_end);
+	}
+#endif /* if defined(CONFIG_BLK_DEV_INITRD) */
+}
+
+__init void process_uboot_commandline(char *commandp, int size)
+{
+	int len, n;
+
+	n = strnlen(commandp, size);
+	commandp += n;
+	len = size - n;
+	if (len) {
+		/* Add the whitespace separator */
+		*commandp++ = ' ';
+		len--;
+	}
+
+	parse_uboot_commandline(commandp, len);
+	commandp[size - 1] = 0;
+}
-- 
cgit