openwrt/target/linux/ixp4xx/patches-2.6.23/096-kexec_cmdline.patch

diff -uprN linux-2.6.23.orig/kernel/ksysfs.c linux-2.6.23/kernel/ksysfs.c
--- linux-2.6.23.orig/kernel/ksysfs.c	2007-10-09 15:31:38.000000000 -0500
+++ linux-2.6.23/kernel/ksysfs.c	2007-10-11 01:10:26.000000000 -0500
@@ -49,6 +49,165 @@ KERNEL_ATTR_RW(uevent_helper);
 #endif
 
 #ifdef CONFIG_KEXEC
+
+#include <asm/setup.h>
+
+extern unsigned long kexec_boot_params;
+
+char kexec_cmdline[COMMAND_LINE_SIZE] = "";
+
+static void
+replace_cmdline_tag(void)
+{
+	char *t;
+	struct tag *real;
+	struct tag *copy;
+	struct tag *rend;
+	int i;
+
+/* TODO: check the return params */
+	t = kmalloc(KEXEC_BOOT_PARAMS_SIZE + COMMAND_LINE_SIZE, GFP_KERNEL);
+	memset((void *)t, 0, KEXEC_BOOT_PARAMS_SIZE + COMMAND_LINE_SIZE);
+
+/* TODO: validate that the boot params are ATAGS, in fact */
+
+	copy = (struct tag *)t;
+	real = (struct tag *)kexec_boot_params;
+	rend = (struct tag *)(kexec_boot_params + KEXEC_BOOT_PARAMS_SIZE);
+	while ((real->hdr.size) && (real < rend)) {
+		if (real->hdr.tag != ATAG_CMDLINE) {
+			memcpy((void *)copy, (void *)real, real->hdr.size * 4);
+			copy = tag_next(copy);
+		}
+		real = tag_next(real);
+	}
+
+/* TODO: validate that we have enough space in the buffer */
+	
+	i = strlen(kexec_cmdline);
+	if (i) {
+		copy->hdr.tag = ATAG_CMDLINE;
+		copy->hdr.size = (sizeof(struct tag_header) + i + 1 + 4) >> 2;
+		strcpy(copy->u.cmdline.cmdline, kexec_cmdline);
+		copy = tag_next(copy);
+	}
+
+	copy->hdr.tag = ATAG_NONE;            /* Empty tag ends list */
+	copy->hdr.size = 0;                   /* zero length */
+
+/* TODO: validate that the temporary buffer isn't too full */
+
+	memcpy((void *)kexec_boot_params, (void *)t, KEXEC_BOOT_PARAMS_SIZE);
+
+	kfree(t);  /* Don't forget to free the big buffer we used */
+}
+
+static ssize_t kexec_cmdline_show(struct kset *kset, char *page)
+{
+	return sprintf(page, "%s\n", kexec_cmdline);
+}
+
+static ssize_t kexec_cmdline_store(struct kset *kset, const char *page,
+				   size_t count)
+{
+	if ((count + 1) > COMMAND_LINE_SIZE)
+		count = COMMAND_LINE_SIZE;
+	memcpy(kexec_cmdline, page, count);
+	kexec_cmdline[count] = '\0';
+	if (count && (kexec_cmdline[count - 1] == '\n'))
+		kexec_cmdline[count - 1] = '\0';
+	replace_cmdline_tag();
+	return count;
+}
+KERNEL_ATTR_RW(kexec_cmdline);
+
+static ssize_t kexec_boot_params_show(struct kset *kset, char *page)
+{
+	unsigned long *p;
+	char buf[PAGE_SIZE];
+	int keep_doing;
+
+	p = (unsigned long *)kexec_boot_params;
+
+	/* if this doesn't look like atags, just print first few words */
+	if (p[1] != ATAG_CORE)
+		return sprintf(page, "0x%lx 0x%lx 0x%lx 0x%lx\n",
+			       p[0], p[1], p[2], p[3]);
+
+	/* carefully walk the atag list, and print out the structure */
+	keep_doing = 1;
+	do {
+		switch (p[1]) {
+		case ATAG_CORE:
+			/* watch out, core tag is permitted to be empty */
+			if (p[0] == 5)
+				sprintf(buf,
+					"CORE flg=%ld pgsz=%ld rdev=0x%lx\n",
+					p[2], p[3], p[4]);
+			else
+				sprintf(buf,"CORE\n");
+			break;
+		case ATAG_MEM:
+			sprintf(buf,"MEM  %ldM@0x%lx\n", p[2] / (1024 * 1024),
+				p[3]);
+			break;
+		case ATAG_VIDEOTEXT:
+			sprintf(buf,"VIDEOTEXT sz=%ld\n", p[0]);
+			break;
+		case ATAG_RAMDISK:
+			sprintf(buf,"RAMDISK prmpt=%ld %ldK@0x%lx\n",
+				p[2], p[3], p[4]);
+			break;
+		case ATAG_INITRD2:
+			sprintf(buf,"INITRD2 %ldK@0x%lx\n", p[3] / 1024, p[2]);
+			break;
+		case ATAG_SERIAL:
+			sprintf(buf,"SERIAL high=0x%08lx low=0x%08lx\n",
+				p[3], p[2]);
+			break;
+		case ATAG_REVISION:
+			sprintf(buf,"REVISION rev=%ld\n", p[2]);
+			break;
+		case ATAG_VIDEOLFB:
+			sprintf(buf,"VIDEOLFB sz=%ld\n", p[0]);
+			break;
+		case ATAG_CMDLINE:
+			sprintf(buf,"CMD  \"%s\"\n", (char *)&p[2]);
+			break;
+		case ATAG_NONE:
+			sprintf(buf,"NONE\n");
+			keep_doing = 0;
+			break;
+		default:
+			sprintf(buf,"-unknown- sz=%ld\n", p[0]);
+			break;
+		}
+
+		/* carefully add to page */
+		if ((strlen(buf) + strlen(page)) < PAGE_SIZE) {
+			strcat(page, buf);
+		} else {
+			keep_doing = 0;
+		}
+
+		/* stop when we encounter a header length of 0 */
+		if (p[0] == 0)
+			keep_doing = 0;
+
+		/* go to the next tag */
+		p += p[0];
+
+		/* stop if we walked off the end of the buffer */
+		if (p > (unsigned long *)(kexec_boot_params +
+					  KEXEC_BOOT_PARAMS_SIZE))
+			keep_doing = 0;
+
+	} while (keep_doing);
+
+	return (strlen(page));
+}
+KERNEL_ATTR_RO(kexec_boot_params);
+
 static ssize_t kexec_loaded_show(struct kset *kset, char *page)
 {
 	return sprintf(page, "%d\n", !!kexec_image);
@@ -95,6 +254,8 @@ static struct attribute * kernel_attrs[]
 #ifdef CONFIG_KEXEC
 	&kexec_loaded_attr.attr,
 	&kexec_crash_loaded_attr.attr,
+	&kexec_cmdline_attr.attr,
+	&kexec_boot_params_attr.attr,
 #endif
 	NULL
 };