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 
24 extern uint32_t __eedata_start[], __eedata_end[];
25 
26 //STM32F4xx eedata stores data in 4-byte aligned chunks
27 
eeFind(uint32_t nameToFind,uint32_t * offset,bool findFirst,uint32_t * szP)28 static 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 
eeIsValidName(uint32_t name)63 static bool eeIsValidName(uint32_t name)
64 {
65     return name && name < EE_DATA_NAME_MAX;
66 }
67 
eeDataGetEx(uint32_t name,uint32_t * offsetP,bool first,void * buf,uint32_t * szP)68 static 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 
eeDataGetSize()93 uint32_t eeDataGetSize()
94 {
95     return __eedata_end - __eedata_start;
96 }
97 
eeDataGetFree()98 uint32_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 
eeDataGet(uint32_t name,void * buf,uint32_t * szP)121 bool 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 
eeDataGetAllVersions(uint32_t name,void * buf,uint32_t * szP,void ** stateP)128 void *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 
eeWrite(void * dst,const void * src,uint32_t len)136 static 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 
eeDataSet(uint32_t name,const void * buf,uint32_t len)141 bool 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 
eeDataEraseOldVersion(uint32_t name,void * vaddr)169 bool 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