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/* Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "2sysincludes.h"
#include "2common.h"
#include "sysincludes.h"
#include "cgptlib.h"
#include "cgptlib_internal.h"
#include "crc32.h"
#include "gpt.h"
#include "utility.h"
#include "vboot_api.h"
int GptInit(GptData *gpt)
{
int retval;
gpt->modified = 0;
gpt->current_kernel = CGPT_KERNEL_ENTRY_NOT_FOUND;
gpt->current_priority = 999;
retval = GptSanityCheck(gpt);
if (GPT_SUCCESS != retval) {
VB2_DEBUG("GptInit() failed sanity check\n");
return retval;
}
GptRepair(gpt);
return GPT_SUCCESS;
}
int GptNextKernelEntry(GptData *gpt, uint64_t *start_sector, uint64_t *size)
{
GptHeader *header = (GptHeader *)gpt->primary_header;
GptEntry *entries = (GptEntry *)gpt->primary_entries;
GptEntry *e;
int new_kernel = CGPT_KERNEL_ENTRY_NOT_FOUND;
int new_prio = 0;
uint32_t i;
/*
* If we already found a kernel, continue the scan at the current
* kernel's priority, in case there is another kernel with the same
* priority.
*/
if (gpt->current_kernel != CGPT_KERNEL_ENTRY_NOT_FOUND) {
for (i = gpt->current_kernel + 1;
i < header->number_of_entries; i++) {
e = entries + i;
if (!IsKernelEntry(e))
continue;
VB2_DEBUG("GptNextKernelEntry looking at same prio "
"partition %d\n", i+1);
VB2_DEBUG("GptNextKernelEntry s%d t%d p%d\n",
GetEntrySuccessful(e), GetEntryTries(e),
GetEntryPriority(e));
if (!(GetEntrySuccessful(e) || GetEntryTries(e)))
continue;
if (GetEntryPriority(e) == gpt->current_priority) {
gpt->current_kernel = i;
*start_sector = e->starting_lba;
*size = e->ending_lba - e->starting_lba + 1;
VB2_DEBUG("GptNextKernelEntry likes it\n");
return GPT_SUCCESS;
}
}
}
/*
* We're still here, so scan for the remaining kernel with the highest
* priority less than the previous attempt.
*/
for (i = 0, e = entries; i < header->number_of_entries; i++, e++) {
int current_prio = GetEntryPriority(e);
if (!IsKernelEntry(e))
continue;
VB2_DEBUG("GptNextKernelEntry looking at new prio "
"partition %d\n", i+1);
VB2_DEBUG("GptNextKernelEntry s%d t%d p%d\n",
GetEntrySuccessful(e), GetEntryTries(e),
GetEntryPriority(e));
if (!(GetEntrySuccessful(e) || GetEntryTries(e)))
continue;
if (current_prio >= gpt->current_priority) {
/* Already returned this kernel in a previous call */
continue;
}
if (current_prio > new_prio) {
new_kernel = i;
new_prio = current_prio;
}
}
/*
* Save what we found. Note that if we didn't find a new kernel,
* new_prio will still be -1, so future calls to this function will
* also fail.
*/
gpt->current_kernel = new_kernel;
gpt->current_priority = new_prio;
if (CGPT_KERNEL_ENTRY_NOT_FOUND == new_kernel) {
VB2_DEBUG("GptNextKernelEntry no more kernels\n");
return GPT_ERROR_NO_VALID_KERNEL;
}
VB2_DEBUG("GptNextKernelEntry likes partition %d\n", new_kernel + 1);
e = entries + new_kernel;
*start_sector = e->starting_lba;
*size = e->ending_lba - e->starting_lba + 1;
return GPT_SUCCESS;
}
/*
* Func: GptUpdateKernelWithEntry
* Desc: This function updates the given kernel entry according to the provided
* update_type.
*/
int GptUpdateKernelWithEntry(GptData *gpt, GptEntry *e, uint32_t update_type)
{
int modified = 0;
if (!IsKernelEntry(e))
return GPT_ERROR_INVALID_UPDATE_TYPE;
switch (update_type) {
case GPT_UPDATE_ENTRY_TRY: {
/* Used up a try */
int tries;
if (GetEntrySuccessful(e)) {
/*
* Successfully booted this partition, so tries field
* is ignored.
*/
return GPT_SUCCESS;
}
tries = GetEntryTries(e);
if (tries > 1) {
/* Still have tries left */
modified = 1;
SetEntryTries(e, tries - 1);
break;
}
/* Out of tries, so drop through and mark partition bad. */
}
/* fall through */
case GPT_UPDATE_ENTRY_BAD: {
/* Giving up on this partition entirely. */
if (!GetEntrySuccessful(e)) {
/*
* Only clear tries and priority if the successful bit
* is not set.
*/
modified = 1;
SetEntryTries(e, 0);
SetEntryPriority(e, 0);
}
break;
}
case GPT_UPDATE_ENTRY_ACTIVE: {
/*
* Used for fastboot mode. If kernel partition slot is marked
* active, its GPT entry is marked with S1,P2,T0.
*/
modified = 1;
SetEntryTries(e, 0);
SetEntryPriority(e, 2);
SetEntrySuccessful(e, 1);
break;
}
case GPT_UPDATE_ENTRY_INVALID: {
/*
* Used for fastboot mode. If kernel partition slot is marked
* invalid, its GPT entry is marked with S0,P0,T0
*/
modified = 1;
SetEntryTries(e, 0);
SetEntryPriority(e, 0);
SetEntrySuccessful(e, 0);
break;
}
default:
return GPT_ERROR_INVALID_UPDATE_TYPE;
}
if (modified) {
GptModified(gpt);
}
return GPT_SUCCESS;
}
/*
* Func: GptUpdateKernelEntry
* Desc: This function updates current_kernel entry with provided
* update_type. If current_kernel is not set, then it returns error.
*/
int GptUpdateKernelEntry(GptData *gpt, uint32_t update_type)
{
GptEntry *entries = (GptEntry *)gpt->primary_entries;
GptEntry *e = entries + gpt->current_kernel;
if (gpt->current_kernel == CGPT_KERNEL_ENTRY_NOT_FOUND)
return GPT_ERROR_INVALID_UPDATE_TYPE;
return GptUpdateKernelWithEntry(gpt, e, update_type);
}
/*
* Func: GptFindNthEntry
* Desc: This function returns the nth instance of parition entry matching the
* partition type guid from the gpt table. Instance value starts from 0. If the
* entry is not found it returns NULL.
*/
GptEntry *GptFindNthEntry(GptData *gpt, const Guid *guid, unsigned int n)
{
GptHeader *header = (GptHeader *)gpt->primary_header;
GptEntry *entries = (GptEntry *)gpt->primary_entries;
GptEntry *e;
int i;
for (i = 0, e = entries; i < header->number_of_entries; i++, e++) {
if (!memcmp(&e->type, guid, sizeof(*guid))) {
if (n == 0)
return e;
n--;
}
}
return NULL;
}
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