1 files changed, 141 insertions, 0 deletions

diff --git a/arch/ppc/syslib/prep_nvram.c b/arch/ppc/syslib/prep_nvram.c
new file mode 100644
index 000000000000..2bcf8a16d1c9
--- /dev/null
+++ b/arch/ppc/syslib/prep_nvram.c
@@ -0,0 +1,141 @@
+/*
+ * arch/ppc/kernel/prep_nvram.c
+ *
+ * Copyright (C) 1998  Corey Minyard
+ *
+ * This reads the NvRAM on PReP compliant machines (generally from IBM or
+ * Motorola).  Motorola kept the format of NvRAM in their ROM, PPCBUG, the
+ * same, long after they had stopped producing PReP compliant machines.  So
+ * this code is useful in those cases as well.
+ *
+ */
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/ioport.h>
+
+#include <asm/sections.h>
+#include <asm/segment.h>
+#include <asm/io.h>
+#include <asm/machdep.h>
+#include <asm/prep_nvram.h>
+
+static char nvramData[MAX_PREP_NVRAM];
+static NVRAM_MAP *nvram=(NVRAM_MAP *)&nvramData[0];
+
+unsigned char __prep prep_nvram_read_val(int addr)
+{
+        outb(addr, PREP_NVRAM_AS0);
+        outb(addr>>8, PREP_NVRAM_AS1);
+        return inb(PREP_NVRAM_DATA);
+}
+
+void __prep prep_nvram_write_val(int           addr,
+                          unsigned char val)
+{
+        outb(addr, PREP_NVRAM_AS0);
+        outb(addr>>8, PREP_NVRAM_AS1);
+        outb(val, PREP_NVRAM_DATA);
+}
+
+void __init init_prep_nvram(void)
+{
+        unsigned char *nvp;
+        int  i;
+        int  nvramSize;
+
+        /*
+         * The following could fail if the NvRAM were corrupt but
+         * we expect the boot firmware to have checked its checksum
+         * before boot
+         */
+        nvp = (char *) &nvram->Header;
+        for (i=0; i<sizeof(HEADER); i++)
+        {
+                *nvp = ppc_md.nvram_read_val(i);
+                nvp++;
+        }
+
+        /*
+         * The PReP NvRAM may be any size so read in the header to
+         * determine how much we must read in order to get the complete
+         * GE area
+         */
+        nvramSize=(int)nvram->Header.GEAddress+nvram->Header.GELength;
+        if(nvramSize>MAX_PREP_NVRAM)
+        {
+                /*
+                 * NvRAM is too large
+                 */
+                nvram->Header.GELength=0;
+                return;
+        }
+
+        /*
+         * Read the remainder of the PReP NvRAM
+         */
+        nvp = (char *) &nvram->GEArea[0];
+        for (i=sizeof(HEADER); i<nvramSize; i++)
+        {
+                *nvp = ppc_md.nvram_read_val(i);
+                nvp++;
+        }
+}
+
+__prep
+char __prep *prep_nvram_get_var(const char *name)
+{
+        char *cp;
+        int  namelen;
+
+        namelen = strlen(name);
+        cp = prep_nvram_first_var();
+        while (cp != NULL) {
+                if ((strncmp(name, cp, namelen) == 0)
+                    && (cp[namelen] == '='))
+                {
+                        return cp+namelen+1;
+                }
+                cp = prep_nvram_next_var(cp);
+        }
+
+        return NULL;
+}
+
+__prep
+char __prep *prep_nvram_first_var(void)
+{
+        if (nvram->Header.GELength == 0) {
+                return NULL;
+        } else {
+                return (((char *)nvram)
+                        + ((unsigned int) nvram->Header.GEAddress));
+        }
+}
+
+__prep
+char __prep *prep_nvram_next_var(char *name)
+{
+        char *cp;
+
+
+        cp = name;
+        while (((cp - ((char *) nvram->GEArea)) < nvram->Header.GELength)
+               && (*cp != '\0'))
+        {
+                cp++;
+        }
+
+        /* Skip over any null characters. */
+        while (((cp - ((char *) nvram->GEArea)) < nvram->Header.GELength)
+               && (*cp == '\0'))
+        {
+                cp++;
+        }
+
+        if ((cp - ((char *) nvram->GEArea)) < nvram->Header.GELength) {
+                return cp;
+        } else {
+                return NULL;
+        }
+}