contrib/loaders/flash/fm4/erase.S

   1 /*
   2  * Spansion FM4 flash sector erase algorithm
   3  *
   4  * Copyright (c) 2015 Andreas Färber
   5  *
   6  * Based on S6E2CC_MN709-00007 for S6E2CC/C5/C4/C3/C2/C1 series
   7  */
   8
   9 #include "fm4.h"
  10
  11 #define RESULT_OKAY     0
  12 #define RESULT_NONE     1
  13 #define RESULT_TIMEOUT  2
  14
  15         .macro busy_wait, res, addr, tmp1, tmp2, tmp3
  16
  17         ldrb    \tmp1, [\addr] /* ignore */
  18 1001:
  19         ldrb    \tmp1, [\addr]
  20         ldrb    \tmp2, [\addr]
  21
  22         and     \tmp3, \tmp1, #FLASH_TOGG
  23         and     \tmp2, \tmp2, #FLASH_TOGG
  24         cmp     \tmp3, \tmp2
  25         beq     1010f
  26
  27         and     \tmp2, \tmp1, #FLASH_TLOV
  28         cmp     \tmp2, #0
  29         beq     1001b
  30
  31         ldrb    \tmp1, [\addr]
  32         ldrb    \tmp2, [\addr]
  33
  34         and     \tmp3, \tmp1, #FLASH_TOGG
  35         and     \tmp2, \tmp2, #FLASH_TOGG
  36         cmp     \tmp3, \tmp2
  37         beq     1010f
  38
  39         mov     \res, #RESULT_TIMEOUT
  40         bkpt    #0
  41 1010:
  42         mov     \res, #RESULT_OKAY
  43
  44         .endm
  45
  46
  47         .macro erase, cmdseqaddr1, cmdseqaddr2, sa, res, tmp1, tmp2, tmp3
  48
  49         mov     \res, #RESULT_NONE
  50
  51         mov     \tmp1, #0xAA
  52         strh    \tmp1, [\cmdseqaddr1]
  53         mov     \tmp2, #0x55
  54         strh    \tmp2, [\cmdseqaddr2]
  55         mov     \tmp3, #0x80
  56         strh    \tmp3, [\cmdseqaddr1]
  57         strh    \tmp1, [\cmdseqaddr1]
  58         strh    \tmp2, [\cmdseqaddr2]
  59         mov     \tmp3, #0x30
  60         strh    \tmp3, [\sa]
  61
  62         busy_wait \res, \sa, \tmp1, \tmp2, \tmp3
  63
  64         .endm
  65
  66
  67         /* r0 = 0xAA8
  68          * r1 = 0x554
  69          * r2 = SA
  70          * r3 = result
  71          */
  72 erase:
  73         erase r0, r1, r2, r3, r4, r5, r6
  74
  75         bkpt    #0
  76
  77 data: