patch-2.3.9 linux/arch/mips/dec/prom/memory.c

• Lines: 104
• Date: Wed Jun 30 11:24:54 1999
• Orig file: v2.3.8/linux/arch/mips/dec/prom/memory.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.8/linux/arch/mips/dec/prom/memory.c linux/arch/mips/dec/prom/memory.c
@@ -0,0 +1,103 @@
+/*
+ * memory.c: memory initialisation code.
+ *
+ * Copyright (C) 1998 Harald Koerfgen, Frieder Streffer and Paul M. Antoine
+ *
+ * $Id: $
+ */
+#include <asm/addrspace.h>
+#include <linux/init.h>
+#include <linux/string.h>
+#include "prom.h"
+
+typedef struct {
+	int pagesize;
+	unsigned char bitmap[0];
+} memmap;
+
+extern int (*rex_getbitmap)(memmap *);
+
+#undef PROM_DEBUG
+
+#ifdef PROM_DEBUG
+extern int (*prom_printf)(char *, ...);
+#endif
+
+extern unsigned long mips_memory_upper;
+
+volatile unsigned long mem_err = 0;	/* So we know an error occured */
+
+/*
+ * Probe memory in 4MB chunks, waiting for an error to tell us we've fallen
+ * off the end of real memory.  Only suitable for the 2100/3100's (PMAX).
+ */
+
+#define CHUNK_SIZE 0x400000
+
+__initfunc(unsigned long pmax_get_memory_size(void))
+{
+	volatile unsigned char *memory_page, dummy;
+	char	old_handler[0x80];
+	extern char genexcept_early;
+
+	/* Install exception handler */
+	memcpy(&old_handler, (void *)(KSEG0 + 0x80), 0x80);
+	memcpy((void *)(KSEG0 + 0x80), &genexcept_early, 0x80);
+
+	/* read unmapped and uncached (KSEG1)
+	 * DECstations have at least 4MB RAM
+	 * Assume less than 480MB of RAM, as this is max for 5000/2xx
+	 * FIXME this should be replaced by the first free page!
+	 */
+	for (memory_page = (unsigned char *) KSEG1 + CHUNK_SIZE;
+	     (mem_err== 0) && (memory_page < ((unsigned char *) KSEG1+0x1E000000));
+  	     memory_page += CHUNK_SIZE) {
+		dummy = *memory_page;
+	}
+	memcpy((void *)(KSEG0 + 0x80), &old_handler, 0x80);
+	return (unsigned long)memory_page - KSEG1 - CHUNK_SIZE;
+}
+
+/*
+ * Use the REX prom calls to get hold of the memory bitmap, and thence
+ * determine memory size.
+ */
+__initfunc(unsigned long rex_get_memory_size(void))
+{
+	int i, bitmap_size;
+	unsigned long mem_size = 0;
+	memmap *bm;
+
+	/* some free 64k */
+	bm = (memmap *) 0x80028000;
+
+	bitmap_size = rex_getbitmap(bm);
+
+	for (i = 0; i < bitmap_size; i++) {
+		/* FIXME: very simplistically only add full sets of pages */
+		if (bm->bitmap[i] == 0xff)
+			mem_size += (8 * bm->pagesize);
+	}
+	return (mem_size);
+}
+
+__initfunc(void prom_meminit(unsigned int magic))
+{
+	if (magic != REX_PROM_MAGIC)
+		mips_memory_upper = KSEG0 + pmax_get_memory_size();
+	else
+		mips_memory_upper = KSEG0 + rex_get_memory_size();
+
+#ifdef PROM_DEBUG
+	prom_printf("mips_memory_upper: 0x%08x\n", mips_memory_upper);
+#endif
+}
+
+/* Called from mem_init() to fixup the mem_map page settings. */
+__initfunc(void prom_fixup_mem_map(unsigned long start, unsigned long end))
+{
+}
+
+void prom_free_prom_memory (void)
+{
+}