patch-2.1.44 linux/arch/mips/lib/tags.c

• Lines: 76
• Date: Thu Jun 26 12:33:37 1997
• Orig file: v2.1.43/linux/arch/mips/lib/tags.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.43/linux/arch/mips/lib/tags.c linux/arch/mips/lib/tags.c
@@ -0,0 +1,75 @@
+/*
+ *  linux/arch/mips/lib/tags.c
+ *
+ *  Copyright (C) 1996  Stoned Elipot
+ */
+#include <linux/stddef.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <asm/addrspace.h>
+#include <asm/bootinfo.h>
+
+/*
+ * Parse the tags present in upper memory to find out
+ * a pecular one.
+ *
+ * Parameter: type - tag type to find
+ * 
+ * returns  : NULL  - failure
+ *            !NULL - pointer on the tag structure found 
+ */
+tag *
+bi_TagFind(enum bi_tag type)
+{
+	tag* t = (tag*)(mips_memory_upper - sizeof(tag));
+
+	while((t->tag != tag_dummy) && (t->tag != type))
+		t = (tag*)(NEXTTAGPTR(t));
+
+	if (t->tag == tag_dummy)		/* tag not found */
+		return (tag*)NULL;
+
+	return t;
+}
+
+/*
+ * Snarf from the tag list in memory end some tags needed
+ * before the kernel reachs setup_arch()
+ *
+ * add yours here if you want to, but *beware*: the kernel var
+ * that will hold the values you want to snarf have to be
+ * in .data section of the kernel, so initialized in to whatever
+ * value in the kernel's sources.
+ */
+void bi_EarlySnarf(void)
+{
+	tag* atag;
+  
+	/* for wire_mappings() */
+	atag = bi_TagFind(tag_machgroup);
+	if (atag)
+		memcpy(&mips_machgroup, TAGVALPTR(atag), atag->size);
+	else {
+		/* useless for boxes without text video mode but....*/
+		panic("machine group not specified by bootloader");
+	}
+
+	atag = bi_TagFind(tag_machtype);
+	if (atag)
+		memcpy(&mips_machtype, TAGVALPTR(atag), atag->size);
+	else {
+		/* useless for boxes without text video mode but....*/
+		panic("machine type not specified by bootloader");
+	}
+
+	/* for tlbflush() */
+	atag = bi_TagFind(tag_tlb_entries);
+	if (atag)
+		memcpy(&mips_tlb_entries, TAGVALPTR(atag), atag->size);
+	else {
+		/* useless for boxes without text video mode but....*/
+		panic("number of TLB entries not specified by bootloader");
+	}
+
+	return;
+}