arch/cris/arch-v10/boot/rescue/kimagerescue.S

   1 /*
   2  * Rescue code to be prepended on a kimage and copied to the
   3  * rescue serial port.
   4  * This is called from the rescue code, it will copy received data to
   5  * 4004000 and after a timeout jump to it.
   6  */
   7
   8 #define ASSEMBLER_MACROS_ONLY
   9 #include <arch/sv_addr_ag.h>
  10
  11 #define CODE_START 0x40004000
  12 #define CODE_LENGTH 784
  13 #define TIMEOUT_VALUE 1000
  14
  15
  16 #ifdef CONFIG_ETRAX_RESCUE_SER0
  17 #define SERXOFF R_SERIAL0_XOFF
  18 #define SERBAUD R_SERIAL0_BAUD
  19 #define SERRECC R_SERIAL0_REC_CTRL
  20 #define SERRDAT R_SERIAL0_REC_DATA
  21 #define SERSTAT R_SERIAL0_STATUS
  22 #endif
  23 #ifdef CONFIG_ETRAX_RESCUE_SER1
  24 #define SERXOFF R_SERIAL1_XOFF
  25 #define SERBAUD R_SERIAL1_BAUD
  26 #define SERRECC R_SERIAL1_REC_CTRL
  27 #define SERRDAT R_SERIAL1_REC_DATA
  28 #define SERSTAT R_SERIAL1_STATUS
  29 #endif
  30 #ifdef CONFIG_ETRAX_RESCUE_SER2
  31 #define SERXOFF R_SERIAL2_XOFF
  32 #define SERBAUD R_SERIAL2_BAUD
  33 #define SERRECC R_SERIAL2_REC_CTRL
  34 #define SERRDAT R_SERIAL2_REC_DATA
  35 #define SERSTAT R_SERIAL2_STATUS
  36 #endif
  37 #ifdef CONFIG_ETRAX_RESCUE_SER3
  38 #define SERXOFF R_SERIAL3_XOFF
  39 #define SERBAUD R_SERIAL3_BAUD
  40 #define SERRECC R_SERIAL3_REC_CTRL
  41 #define SERRDAT R_SERIAL3_REC_DATA
  42 #define SERSTAT R_SERIAL3_STATUS
  43 #endif
  44
  45         .text
  46         ;; This is the entry point of the rescue code
  47         ;; 0x80000000 if loaded in flash (as it should be)
  48         ;; since etrax actually starts at address 2 when booting from flash, we
  49         ;; put a nop (2 bytes) here first so we dont accidentally skip the di
  50
  51         nop
  52         di
  53 #ifndef CONFIG_SVINTO_SIM
  54         ;; setup port PA and PB default initial directions and data
  55         ;; (so we can flash LEDs, and so that DTR and others are set)
  56
  57         move.b  CONFIG_ETRAX_DEF_R_PORT_PA_DIR, $r0
  58         move.b  $r0, [R_PORT_PA_DIR]
  59         move.b  CONFIG_ETRAX_DEF_R_PORT_PA_DATA, $r0
  60         move.b  $r0, [R_PORT_PA_DATA]
  61
  62         move.b  CONFIG_ETRAX_DEF_R_PORT_PB_DIR, $r0
  63         move.b  $r0, [R_PORT_PB_DIR]
  64         move.b  CONFIG_ETRAX_DEF_R_PORT_PB_DATA, $r0
  65         move.b  $r0, [R_PORT_PB_DATA]
  66
  67         ;; We need to setup the bus registers before we start using the DRAM
  68 #include "../../lib/dram_init.S"
  69
  70 #endif
  71         ;; Setup the stack to a suitably high address.
  72         ;; We assume 8 MB is the minimum DRAM in an eLinux
  73         ;; product and put the sp at the top for now.
  74
  75         move.d  0x40800000, $sp
  76
  77         ;; setup the serial port at 115200 baud
  78
  79         moveq   0, $r0
  80         move.d  $r0, [SERXOFF]
  81
  82         move.b  0x99, $r0
  83         move.b  $r0, [SERBAUD]          ; 115.2kbaud for both transmit
  84                                         ; and receive
  85
  86         move.b  0x40, $r0               ; rec enable
  87         move.b  $r0, [SERRECC]
  88
  89
  90         moveq   0, $r1                  ; "timer" to clock out a LED red flash
  91         move.d  CODE_START, $r3         ; destination counter
  92         move.d  CODE_LENGTH, $r4        ; length
  93         move.d  TIMEOUT_VALUE, $r5      ; "timeout" until jump
  94
  95 wait_ser:
  96         addq    1, $r1
  97         subq    1, $r5                  ; decrease timeout
  98         beq     jump_start              ; timed out
  99         nop
 100 #ifndef CONFIG_ETRAX_NO_LEDS
 101 #ifdef CONFIG_ETRAX_PA_LEDS
 102         move.b  CONFIG_ETRAX_DEF_R_PORT_PA_DATA, $r2
 103 #endif
 104 #ifdef CONFIG_ETRAX_PB_LEDS
 105         move.b  CONFIG_ETRAX_DEF_R_PORT_PB_DATA, $r2
 106 #endif
 107         move.d  (1 << CONFIG_ETRAX_LED1R) | (1 << CONFIG_ETRAX_LED2R), $r0
 108         btstq   16, $r1
 109         bpl     1f
 110         nop
 111         or.d    $r0, $r2                ; set bit
 112         ba      2f
 113         nop
 114 1:      not     $r0                     ; clear bit
 115         and.d   $r0, $r2
 116 2:
 117 #ifdef CONFIG_ETRAX_PA_LEDS
 118         move.b  $r2, [R_PORT_PA_DATA]
 119 #endif
 120 #ifdef CONFIG_ETRAX_PB_LEDS
 121         move.b  $r2, [R_PORT_PB_DATA]
 122 #endif
 123 #endif
 124
 125         ;; check if we got something on the serial port
 126
 127         move.b  [SERSTAT], $r0
 128         btstq   0, $r0                  ; data_avail
 129         bpl     wait_ser
 130         nop
 131
 132         ;; got something - copy the byte and loop
 133
 134         move.b  [SERRDAT], $r0
 135         move.b  $r0, [$r3+]
 136         move.d  TIMEOUT_VALUE, $r5      ; reset "timeout"
 137         subq    1, $r4                  ; decrease length
 138         bne     wait_ser
 139         nop
 140 jump_start:
 141         ;; jump into downloaded code
 142
 143         jump    CODE_START