Files
lbmk/util/nvmutil/lib/word.c
Leah Rowe f1fda8b43e util/nvmutil: tidy up includes
Signed-off-by: Leah Rowe <leah@libreboot.org>
2026-03-19 07:22:03 +00:00

77 lines
1.5 KiB
C

/* SPDX-License-Identifier: MIT
*
* Copyright (c) 2022-2026 Leah Rowe <leah@libreboot.org>
*
* Manipulate sixteen-bit little-endian
* words on Intel GbE NVM configurations.
*/
#include <sys/types.h>
#include <errno.h>
#include <stddef.h>
#include "../include/common.h"
/*
* GbE NVM files store 16-bit (2-byte) little-endian words.
* We must therefore swap the order when reading or writing.
*
* NOTE: The MAC address words are stored big-endian in-file.
*/
unsigned short
nvm_word(unsigned long pos16, unsigned long p)
{
struct xstate *x = xstatus(0, NULL);
struct xfile *f = &x->f;
unsigned long pos;
check_nvm_bound(pos16, p);
pos = (pos16 << 1) + (p * GBE_PART_SIZE);
return (unsigned short)f->buf[pos] |
((unsigned short)f->buf[pos + 1] << 8);
}
void
set_nvm_word(unsigned long pos16, unsigned long p, unsigned short val16)
{
struct xstate *x = xstatus(0, NULL);
struct xfile *f = &x->f;
unsigned long pos;
check_nvm_bound(pos16, p);
pos = (pos16 << 1) + (p * GBE_PART_SIZE);
f->buf[pos] = (unsigned char)(val16 & 0xff);
f->buf[pos + 1] = (unsigned char)(val16 >> 8);
set_part_modified(p);
}
void
set_part_modified(unsigned long p)
{
struct xstate *x = xstatus(0, NULL);
struct xfile *f = &x->f;
check_bin(p, "part number");
f->part_modified[p] = 1;
}
void
check_nvm_bound(unsigned long c, unsigned long p)
{
/* Block out of bound NVM access
*/
check_bin(p, "part number");
if (c >= NVM_WORDS)
err(ECANCELED, "check_nvm_bound: out of bounds %lu",
(unsigned long)c);
}