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authorGreg Ungerer <gerg@linux-m68k.org>2016-09-05 08:23:50 +0300
committerGreg Ungerer <gerg@linux-m68k.org>2016-09-26 05:02:59 +0300
commitaa5ac789bd96c7a6628a8167de562fa660f1f481 (patch)
tree3cba478fe5cc7c0eec6154dda3d37e7aa7bf77c7 /arch/m68k/kernel/uboot.c
parent2a744007c332f9d604b95aaecb106596c52ab001 (diff)
downloadlinux-aa5ac789bd96c7a6628a8167de562fa660f1f481.tar.xz
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>
Diffstat (limited to 'arch/m68k/kernel/uboot.c')
-rw-r--r--arch/m68k/kernel/uboot.c107
1 files changed, 107 insertions, 0 deletions
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;
+}