mirror of https://gitee.com/openkylin/linux.git
138 lines
2.7 KiB
C
138 lines
2.7 KiB
C
/*
|
|
* 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/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_nvram_read_val(int addr)
|
|
{
|
|
outb(addr, PREP_NVRAM_AS0);
|
|
outb(addr>>8, PREP_NVRAM_AS1);
|
|
return inb(PREP_NVRAM_DATA);
|
|
}
|
|
|
|
void 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++;
|
|
}
|
|
}
|
|
|
|
char *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;
|
|
}
|
|
|
|
char *prep_nvram_first_var(void)
|
|
{
|
|
if (nvram->Header.GELength == 0) {
|
|
return NULL;
|
|
} else {
|
|
return (((char *)nvram)
|
|
+ ((unsigned int) nvram->Header.GEAddress));
|
|
}
|
|
}
|
|
|
|
char *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;
|
|
}
|
|
}
|