coreboot-kgpe-d16/util/nvramtool/layout.c

515 lines
15 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
#include "common.h"
#include "layout.h"
#include "cmos_lowlevel.h"
typedef struct cmos_entry_item_t cmos_entry_item_t;
struct cmos_entry_item_t {
cmos_entry_t item;
cmos_entry_item_t *next;
};
typedef struct cmos_enum_item_t cmos_enum_item_t;
struct cmos_enum_item_t {
cmos_enum_t item;
cmos_enum_item_t *next;
};
static void default_cmos_layout_get_fn(void);
static int areas_overlap(unsigned area_0_start, unsigned area_0_length,
unsigned area_1_start, unsigned area_1_length);
static int entries_overlap(const cmos_entry_t * p, const cmos_entry_t * q);
static const cmos_enum_item_t *find_first_cmos_enum_id(unsigned config_id);
const char checksum_param_name[] = "check_sum";
/* Newer versions of coreboot store the 3 pieces of information below in the
* coreboot table so we don't have to rely on hardcoded values.
*/
/* This is the offset from the start of CMOS of the first byte that the
* checksum is calculated over.
*/
#define CMOS_CHECKSUM_START 49
/* This is the offset from the start of CMOS of the last byte that the
* checksum is calculated over.
*/
#define CMOS_CHECKSUM_END 125
/* This is the offset from the start of CMOS where the coreboot checksum is
* stored.
*/
#define CMOS_CHECKSUM_INDEX 126
/* index of first byte of checksummed area */
unsigned cmos_checksum_start = CMOS_CHECKSUM_START;
/* index of last byte of checksummed area */
unsigned cmos_checksum_end = CMOS_CHECKSUM_END;
/* index of first byte of CMOS checksum (a big-endian 16-bit value) */
unsigned cmos_checksum_index = CMOS_CHECKSUM_INDEX;
/* List is sorted in ascending order according to 'bit' field in
* cmos_entry_t.
*/
static cmos_entry_item_t *cmos_entry_list = NULL;
/* List is sorted in ascending order: first by 'config_id' and then by
* 'value'.
*/
static cmos_enum_item_t *cmos_enum_list = NULL;
static cmos_layout_get_fn_t cmos_layout_get_fn = default_cmos_layout_get_fn;
/****************************************************************************
* entries_overlap
*
* Return 1 if CMOS entries 'p' and 'q' overlap. Else return 0.
****************************************************************************/
static inline int entries_overlap(const cmos_entry_t * p,
const cmos_entry_t * q)
{
return areas_overlap(p->bit, p->length, q->bit, q->length);
}
/****************************************************************************
* cmos_entry_to_const_item
*
* Return a pointer to the cmos_entry_item_t that 'p' is embedded within.
****************************************************************************/
static inline const cmos_entry_item_t *cmos_entry_to_const_item
(const cmos_entry_t * p) {
static const cmos_entry_t *pos = &((cmos_entry_item_t *) 0)->item;
unsigned long offset, address;
offset = (unsigned long)pos;
address = ((unsigned long)p) - offset;
return (const cmos_entry_item_t *)address;
}
/****************************************************************************
* cmos_enum_to_const_item
*
* Return a pointer to the cmos_enum_item_t that 'p' is embedded within.
****************************************************************************/
static inline const cmos_enum_item_t *cmos_enum_to_const_item
(const cmos_enum_t * p) {
static const cmos_enum_t *pos = &((cmos_enum_item_t *) 0)->item;
unsigned long offset, address;
offset = (unsigned long)pos;
address = ((unsigned long)p) - offset;
return (const cmos_enum_item_t *)address;
}
/****************************************************************************
* register_cmos_layout_get_fn
*
* Set 'fn' as the function that will be called to retrieve CMOS layout
* information.
****************************************************************************/
void register_cmos_layout_get_fn(cmos_layout_get_fn_t fn)
{
cmos_layout_get_fn = fn;
}
/****************************************************************************
* get_cmos_layout
*
* Retrieve CMOS layout information and store it in our internal repository.
****************************************************************************/
void get_cmos_layout(void)
{
cmos_layout_get_fn();
}
/****************************************************************************
* add_cmos_entry
*
* Attempt to add CMOS entry 'e' to our internal repository of layout
* information. Return OK on success or an error code on failure. If
* operation fails because 'e' overlaps an existing CMOS entry, '*conflict'
* will be set to point to the overlapping entry.
****************************************************************************/
int add_cmos_entry(const cmos_entry_t * e, const cmos_entry_t ** conflict)
{
cmos_entry_item_t *item, *prev, *new_entry;
*conflict = NULL;
if (e->length < 1)
return LAYOUT_ENTRY_BAD_LENGTH;
if (e->bit % 8 && e->bit / 8 != (e->bit + e->length - 1) / 8)
return LAYOUT_MULTIBYTE_ENTRY_NOT_ALIGNED;
if ((new_entry =
(cmos_entry_item_t *) malloc(sizeof(*new_entry))) == NULL)
out_of_memory();
new_entry->item = *e;
if (cmos_entry_list == NULL) {
new_entry->next = NULL;
cmos_entry_list = new_entry;
return OK;
}
/* Find place in list to insert new entry. List is sorted in ascending
* order.
*/
for (item = cmos_entry_list, prev = NULL;
(item != NULL) && (item->item.bit < e->bit);
prev = item, item = item->next) ;
if (prev == NULL) {
if (entries_overlap(e, &cmos_entry_list->item)) {
*conflict = &cmos_entry_list->item;
goto fail;
}
new_entry->next = cmos_entry_list;
cmos_entry_list = new_entry;
return OK;
}
if (entries_overlap(&prev->item, e)) {
*conflict = &prev->item;
goto fail;
}
if ((item != NULL) && entries_overlap(e, &item->item)) {
*conflict = &item->item;
goto fail;
}
new_entry->next = item;
prev->next = new_entry;
return OK;
fail:
free(new_entry);
return LAYOUT_ENTRY_OVERLAP;
}
/****************************************************************************
* find_cmos_entry
*
* Search for a CMOS entry whose name is 'name'. Return pointer to matching
* entry or NULL if entry not found.
****************************************************************************/
const cmos_entry_t *find_cmos_entry(const char name[])
{
cmos_entry_item_t *item;
for (item = cmos_entry_list; item != NULL; item = item->next) {
if (!strcmp(item->item.name, name))
return &item->item;
}
return NULL;
}
/****************************************************************************
* first_cmos_entry
*
* Return a pointer to the first CMOS entry in our list or NULL if list is
* empty.
****************************************************************************/
const cmos_entry_t *first_cmos_entry(void)
{
return (cmos_entry_list == NULL) ? NULL : &cmos_entry_list->item;
}
/****************************************************************************
* next_cmos_entry
*
* Return a pointer to next entry in list after 'last' or NULL if no more
* entries.
****************************************************************************/
const cmos_entry_t *next_cmos_entry(const cmos_entry_t * last)
{
const cmos_entry_item_t *last_item, *next_item;
last_item = cmos_entry_to_const_item(last);
next_item = last_item->next;
return (next_item == NULL) ? NULL : &next_item->item;
}
/****************************************************************************
* add_cmos_enum
*
* Attempt to add CMOS enum 'e' to our internal repository of layout
* information. Return OK on success or an error code on failure.
****************************************************************************/
int add_cmos_enum(const cmos_enum_t * e)
{
cmos_enum_item_t *item, *prev, *new_enum;
if ((new_enum = (cmos_enum_item_t *) malloc(sizeof(*new_enum))) == NULL)
out_of_memory();
new_enum->item = *e;
if (cmos_enum_list == NULL) {
new_enum->next = NULL;
cmos_enum_list = new_enum;
return OK;
}
/* The list of enums is sorted in ascending order, first by
* 'config_id' and then by 'value'. Look for the first enum
* whose 'config_id' field matches 'e'.
*/
for (item = cmos_enum_list, prev = NULL;
(item != NULL) && (item->item.config_id < e->config_id);
prev = item, item = item->next) ;
if (item == NULL) {
new_enum->next = NULL;
prev->next = new_enum;
return OK;
}
if (item->item.config_id > e->config_id) {
new_enum->next = item;
if (prev == NULL)
cmos_enum_list = new_enum;
else
prev->next = new_enum;
return OK;
}
/* List already contains at least one enum whose 'config_id'
* matches 'e'. Now find proper place to insert 'e' based on
* 'value'.
*/
while (item->item.value < e->value) {
prev = item;
item = item->next;
if ((item == NULL) || (item->item.config_id != e->config_id)) {
new_enum->next = item;
prev->next = new_enum;
return OK;
}
}
if (item->item.value == e->value) {
free(new_enum);
return LAYOUT_DUPLICATE_ENUM;
}
new_enum->next = item;
if (prev == NULL)
cmos_enum_list = new_enum;
else
prev->next = new_enum;
return OK;
}
/****************************************************************************
* find_cmos_enum
*
* Search for an enum that matches 'config_id' and 'value'. If found, return
* a pointer to the mathcing enum. Else return NULL.
****************************************************************************/
const cmos_enum_t *find_cmos_enum(unsigned config_id, unsigned long long value)
{
const cmos_enum_item_t *item;
if ((item = find_first_cmos_enum_id(config_id)) == NULL)
return NULL;
while (item->item.value < value) {
item = item->next;
if ((item == NULL) || (item->item.config_id != config_id))
return NULL;
}
return (item->item.value == value) ? &item->item : NULL;
}
/****************************************************************************
* first_cmos_enum
*
* Return a pointer to the first CMOS enum in our list or NULL if list is
* empty.
****************************************************************************/
const cmos_enum_t *first_cmos_enum(void)
{
return (cmos_enum_list == NULL) ? NULL : &cmos_enum_list->item;
}
/****************************************************************************
* next_cmos_enum
*
* Return a pointer to next enum in list after 'last' or NULL if no more
* enums.
****************************************************************************/
const cmos_enum_t *next_cmos_enum(const cmos_enum_t * last)
{
const cmos_enum_item_t *last_item, *next_item;
last_item = cmos_enum_to_const_item(last);
next_item = last_item->next;
return (next_item == NULL) ? NULL : &next_item->item;
}
/****************************************************************************
* first_cmos_enum_id
*
* Return a pointer to the first CMOS enum in our list that matches
* 'config_id' or NULL if there are no matching enums.
****************************************************************************/
const cmos_enum_t *first_cmos_enum_id(unsigned config_id)
{
const cmos_enum_item_t *item;
item = find_first_cmos_enum_id(config_id);
return (item == NULL) ? NULL : &item->item;
}
/****************************************************************************
* next_cmos_enum_id
*
* Return a pointer to next enum in list after 'last' that matches the
* 'config_id' field of 'last' or NULL if there are no more matching enums.
****************************************************************************/
const cmos_enum_t *next_cmos_enum_id(const cmos_enum_t * last)
{
const cmos_enum_item_t *item;
item = cmos_enum_to_const_item(last)->next;
return ((item == NULL) || (item->item.config_id != last->config_id)) ?
NULL : &item->item;
}
/****************************************************************************
* is_checksum_name
*
* Return 1 if 'name' matches the name of the parameter representing the CMOS
* checksum. Else return 0.
****************************************************************************/
int is_checksum_name(const char name[])
{
return !strcmp(name, checksum_param_name);
}
/****************************************************************************
* checksum_layout_to_bytes
*
* On entry, '*layout' contains checksum-related layout information expressed
* in bits. Perform sanity checking on the information and convert it from
* bit positions to byte positions. Return OK on success or an error code if
* a sanity check fails.
****************************************************************************/
int checksum_layout_to_bytes(cmos_checksum_layout_t * layout)
{
unsigned start, end, index;
start = layout->summed_area_start;
end = layout->summed_area_end;
index = layout->checksum_at;
if (start % 8)
return LAYOUT_SUMMED_AREA_START_NOT_ALIGNED;
if ((end % 8) != 7)
return LAYOUT_SUMMED_AREA_END_NOT_ALIGNED;
if (index % 8)
return LAYOUT_CHECKSUM_LOCATION_NOT_ALIGNED;
if (end <= start)
return LAYOUT_INVALID_SUMMED_AREA;
/* Convert bit positions to byte positions. */
start /= 8;
end /= 8; /* equivalent to "end = ((end - 7) / 8)" */
index /= 8;
if (verify_cmos_byte_index(start) || verify_cmos_byte_index(end))
return LAYOUT_SUMMED_AREA_OUT_OF_RANGE;
if (verify_cmos_byte_index(index))
return LAYOUT_CHECKSUM_LOCATION_OUT_OF_RANGE;
/* checksum occupies 16 bits */
if (areas_overlap(start, end - start + 1, index, index + 1))
return LAYOUT_CHECKSUM_OVERLAPS_SUMMED_AREA;
layout->summed_area_start = start;
layout->summed_area_end = end;
layout->checksum_at = index;
return OK;
}
/****************************************************************************
* checksum_layout_to_bits
*
* On entry, '*layout' contains checksum-related layout information expressed
* in bytes. Convert this information to bit positions.
****************************************************************************/
void checksum_layout_to_bits(cmos_checksum_layout_t * layout)
{
layout->summed_area_start *= 8;
layout->summed_area_end = (layout->summed_area_end * 8) + 7;
layout->checksum_at *= 8;
}
/****************************************************************************
* default_cmos_layout_get_fn
*
* If this function is ever called, it means that an appropriate callback for
* obtaining CMOS layout information was not set before attempting to
* retrieve layout information.
****************************************************************************/
static void default_cmos_layout_get_fn(void)
{
BUG();
}
/****************************************************************************
* areas_overlap
*
* Return 1 if the two given areas overlap. Else return 0.
****************************************************************************/
static int areas_overlap(unsigned area_0_start, unsigned area_0_length,
unsigned area_1_start, unsigned area_1_length)
{
unsigned area_0_end, area_1_end;
area_0_end = area_0_start + area_0_length - 1;
area_1_end = area_1_start + area_1_length - 1;
return ((area_1_start <= area_0_end) && (area_0_start <= area_1_end));
}
/****************************************************************************
* find_first_cmos_enum_id
*
* Return a pointer to the first item in our list of enums that matches
* 'config_id'. Return NULL if there is no matching enum.
****************************************************************************/
static const cmos_enum_item_t *find_first_cmos_enum_id(unsigned config_id)
{
cmos_enum_item_t *item;
for (item = cmos_enum_list;
(item != NULL) && (item->item.config_id < config_id);
item = item->next) ;
return ((item == NULL) || (item->item.config_id > config_id)) ?
NULL : item;
}