1/*
2 * Copyright (C) 2016 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include <stdbool.h>
18#include <stdint.h>
19#include <string.h>
20
21#include <bl.h>
22#include <eeData.h>
23
24extern uint32_t __eedata_start[], __eedata_end[];
25
26//STM32F4xx eedata stores data in 4-byte aligned chunks
27
28static void* eeFind(uint32_t nameToFind, uint32_t *offset, bool findFirst, uint32_t *szP)
29{
30    uint32_t *p = __eedata_start + (offset ? *offset : 0);
31    void *foundData = NULL;
32
33    //find the last incarnation of "name" in flash area
34    while (p < __eedata_end) {
35        uint32_t info = *p++;
36        uint32_t name = info & EE_DATA_NAME_MAX;
37        uint32_t sz = info / (EE_DATA_NAME_MAX + 1);
38        void *data = p;
39
40        //skip over to next data chunk header
41        p += (sz + 3) / 4;
42
43        //check for a match
44        if (nameToFind == name) {
45            *szP = sz;
46            foundData = data;
47
48            if (findFirst)
49                break;
50        }
51
52        //check for ending condition (name == max)
53        if (name == EE_DATA_NAME_MAX)
54            break;
55    }
56
57    if (offset)
58        *offset = p - __eedata_start;
59
60    return foundData;
61}
62
63static bool eeIsValidName(uint32_t name)
64{
65    return name && name < EE_DATA_NAME_MAX;
66}
67
68static void *eeDataGetEx(uint32_t name, uint32_t *offsetP, bool first, void *buf, uint32_t *szP)
69{
70    uint32_t sz = 0;
71    void *data;
72
73    if (!eeIsValidName(name))
74        return false;
75
76    //find the data item
77    data = eeFind(name, offsetP, first, &sz);
78    if (!data)
79        return NULL;
80
81    if (buf && szP) {    //get the data
82        if (sz > *szP)
83            sz = *szP;
84        *szP = sz;
85        memcpy(buf, data, sz);
86    }
87    else if (szP)        //get size
88        *szP = sz;
89
90    return (uint32_t*)data - 1;
91}
92
93uint32_t eeDataGetSize()
94{
95    return __eedata_end - __eedata_start;
96}
97
98uint32_t eeDataGetFree()
99{
100    uint32_t *p = __eedata_start;
101
102    //find the last incarnation of "name" in flash area
103    while (p < __eedata_end) {
104        uint32_t info = *p;
105        uint32_t name = info & EE_DATA_NAME_MAX;
106        uint32_t sz = info / (EE_DATA_NAME_MAX + 1);
107
108        //check for ending condition (name == max)
109        if (name == EE_DATA_NAME_MAX)
110            break;
111
112        p++;
113
114        //skip over to next data chunk header
115        p += (sz + 3) / 4;
116    }
117
118    return __eedata_end - p;
119}
120
121bool eeDataGet(uint32_t name, void *buf, uint32_t *szP)
122{
123    uint32_t offset = 0;
124
125    return eeDataGetEx(name, &offset, false, buf, szP) != NULL;
126}
127
128void *eeDataGetAllVersions(uint32_t name, void *buf, uint32_t *szP, void **stateP)
129{
130    uint32_t offset = *(uint32_t*)stateP;
131    void *addr = eeDataGetEx(name, &offset, true, buf, szP);
132    *(uint32_t*)stateP = offset;
133    return addr;
134}
135
136static bool eeWrite(void *dst, const void *src, uint32_t len)
137{
138    return BL.blProgramEe(dst, src, len, BL_FLASH_KEY1, BL_FLASH_KEY2);
139}
140
141bool eeDataSet(uint32_t name, const void *buf, uint32_t len)
142{
143    uint32_t sz, effectiveSz, info = name + len * (EE_DATA_NAME_MAX + 1);
144    bool ret = true;
145    void *space;
146
147    if (!eeIsValidName(name))
148        return false;
149
150    //find the empty space at the end of everything and make sure it is really empty (size == EE_DATA_LEN_MAX)
151    space = eeFind(EE_DATA_NAME_MAX, NULL, false, &sz);
152    if (!space || sz != EE_DATA_LEN_MAX)
153        return false;
154
155    //calculate effective size
156    effectiveSz = (len + 3) &~ 3;
157
158    //verify we have the space
159    if ((uint8_t*)__eedata_end - (uint8_t*)space < effectiveSz)
160        return false;
161
162    //write it in
163    ret = eeWrite(((uint32_t*)space) - 1, &info, sizeof(info)) && ret;
164    ret = eeWrite(space, buf, len) && ret;
165
166    return ret;
167}
168
169bool eeDataEraseOldVersion(uint32_t name, void *vaddr)
170{
171    uint32_t *addr = (uint32_t*)vaddr;
172    uint32_t v;
173
174    // sanity check
175    if (!eeIsValidName(name) || addr < __eedata_start || addr >= (__eedata_end - 1))
176        return false;
177
178    v = *addr;
179
180    //verify name
181    if ((v & EE_DATA_NAME_MAX) != name)
182        return false;
183
184    //clear name
185    v &=~ EE_DATA_NAME_MAX;
186
187    //store result
188    return eeWrite(addr, &v, sizeof(v));
189}
190