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      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 <plat/inc/bl.h>
     18 #include <stdbool.h>
     19 #include <string.h>
     20 #include <stdint.h>
     21 #include <eeData.h>
     22 
     23 extern uint32_t __eedata_start[], __eedata_end[];
     24 
     25 //STM32F4xx eedata stores data in 4-byte aligned chunks
     26 
     27 static void* eeFind(uint32_t nameToFind, uint32_t *offset, bool findFirst, uint32_t *szP)
     28 {
     29     uint32_t *p = __eedata_start + (offset ? *offset : 0);
     30     void *foundData = NULL;
     31 
     32     //find the last incarnation of "name" in flash area
     33     while (p < __eedata_end) {
     34         uint32_t info = *p++;
     35         uint32_t name = info & EE_DATA_NAME_MAX;
     36         uint32_t sz = info / (EE_DATA_NAME_MAX + 1);
     37         void *data = p;
     38 
     39         //skip over to next data chunk header
     40         p += (sz + 3) / 4;
     41 
     42         //check for a match
     43         if (nameToFind == name) {
     44             *szP = sz;
     45             foundData = data;
     46 
     47             if (findFirst)
     48                 break;
     49         }
     50 
     51         //check for ending condition (name == max)
     52         if (name == EE_DATA_NAME_MAX)
     53             break;
     54     }
     55 
     56     if (offset)
     57         *offset = p - __eedata_start;
     58 
     59     return foundData;
     60 }
     61 
     62 static bool eeIsValidName(uint32_t name)
     63 {
     64     return name && name < EE_DATA_NAME_MAX;
     65 }
     66 
     67 static void *eeDataGetEx(uint32_t name, uint32_t *offsetP, bool first, void *buf, uint32_t *szP)
     68 {
     69     uint32_t sz = 0;
     70     void *data;
     71 
     72     if (!eeIsValidName(name))
     73         return false;
     74 
     75     //find the data item
     76     data = eeFind(name, offsetP, first, &sz);
     77     if (!data)
     78         return NULL;
     79 
     80     if (buf && szP) {    //get the data
     81         if (sz > *szP)
     82             sz = *szP;
     83         *szP = sz;
     84         memcpy(buf, data, sz);
     85     }
     86     else if (szP)        //get size
     87         *szP = sz;
     88 
     89     return (uint32_t*)data - 1;
     90 }
     91 
     92 bool eeDataGet(uint32_t name, void *buf, uint32_t *szP)
     93 {
     94     uint32_t offset = 0;
     95 
     96     return eeDataGetEx(name, &offset, false, buf, szP) != NULL;
     97 }
     98 
     99 void *eeDataGetAllVersions(uint32_t name, void *buf, uint32_t *szP, void **stateP)
    100 {
    101     uint32_t offset = *(uint32_t*)stateP;
    102     void *addr = eeDataGetEx(name, &offset, true, buf, szP);
    103     *(uint32_t*)stateP = offset;
    104     return addr;
    105 }
    106 
    107 static bool eeWrite(void *dst, const void *src, uint32_t len)
    108 {
    109     return BL.blProgramEe(dst, src, len, BL_FLASH_KEY1, BL_FLASH_KEY2);
    110 }
    111 
    112 bool eeDataSet(uint32_t name, const void *buf, uint32_t len)
    113 {
    114     uint32_t sz, effectiveSz, info = name + len * (EE_DATA_NAME_MAX + 1);
    115     bool ret = true;
    116     void *space;
    117 
    118     if (!eeIsValidName(name))
    119         return false;
    120 
    121     //find the empty space at the end of everything and make sure it is really empty (size == EE_DATA_LEN_MAX)
    122     space = eeFind(EE_DATA_NAME_MAX, NULL, false, &sz);
    123     if (!space || sz != EE_DATA_LEN_MAX)
    124         return false;
    125 
    126     //calculate effective size
    127     effectiveSz = (len + 3) &~ 3;
    128 
    129     //verify we have the space
    130     if ((uint8_t*)__eedata_end - (uint8_t*)space < effectiveSz)
    131         return false;
    132 
    133     //write it in
    134     ret = eeWrite(((uint32_t*)space) - 1, &info, sizeof(info)) && ret;
    135     ret = eeWrite(space, buf, len) && ret;
    136 
    137     return ret;
    138 }
    139 
    140 bool eeDataEraseOldVersion(uint32_t name, void *vaddr)
    141 {
    142     uint32_t *addr = (uint32_t*)vaddr;
    143     uint32_t v;
    144 
    145     // sanity check
    146     if (!eeIsValidName(name) || addr < __eedata_start || addr >= (__eedata_end - 1))
    147         return false;
    148 
    149     v = *addr;
    150 
    151     //verify name
    152     if ((v & EE_DATA_NAME_MAX) != name)
    153         return false;
    154 
    155     //clear name
    156     v &=~ EE_DATA_NAME_MAX;
    157 
    158     //store result
    159     return eeWrite(addr, &v, sizeof(v));
    160 }
    161