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

   1 /* $Id: kimagerescue.S,v 1.1 2001/12/17 13:59:27 bjornw Exp $
   2  *
   3  * Rescue code to be prepended on a kimage and copied to the
   4  * rescue serial port.
   5  * This is called from the rescue code, it will copy received data to
   6  * 4004000 and after a timeout jump to it.
   7  */
   8
   9 #include <linux/config.h>
  10 #define ASSEMBLER_MACROS_ONLY
  11 #include <asm/sv_addr_ag.h>
  12
  13 #define CODE_START 0x40004000
  14 #define CODE_LENGTH 784
  15 #define TIMEOUT_VALUE 1000
  16
  17
  18 #ifdef CONFIG_ETRAX_RESCUE_SER0
  19 #define SERXOFF R_SERIAL0_XOFF
  20 #define SERBAUD R_SERIAL0_BAUD
  21 #define SERRECC R_SERIAL0_REC_CTRL
  22 #define SERRDAT R_SERIAL0_REC_DATA
  23 #define SERSTAT R_SERIAL0_STATUS
  24 #endif
  25 #ifdef CONFIG_ETRAX_RESCUE_SER1
  26 #define SERXOFF R_SERIAL1_XOFF
  27 #define SERBAUD R_SERIAL1_BAUD
  28 #define SERRECC R_SERIAL1_REC_CTRL
  29 #define SERRDAT R_SERIAL1_REC_DATA
  30 #define SERSTAT R_SERIAL1_STATUS
  31 #endif
  32 #ifdef CONFIG_ETRAX_RESCUE_SER2
  33 #define SERXOFF R_SERIAL2_XOFF
  34 #define SERBAUD R_SERIAL2_BAUD
  35 #define SERRECC R_SERIAL2_REC_CTRL
  36 #define SERRDAT R_SERIAL2_REC_DATA
  37 #define SERSTAT R_SERIAL2_STATUS
  38 #endif
  39 #ifdef CONFIG_ETRAX_RESCUE_SER3
  40 #define SERXOFF R_SERIAL3_XOFF
  41 #define SERBAUD R_SERIAL3_BAUD
  42 #define SERRECC R_SERIAL3_REC_CTRL
  43 #define SERRDAT R_SERIAL3_REC_DATA
  44 #define SERSTAT R_SERIAL3_STATUS
  45 #endif
  46
  47         .text
  48         ;; This is the entry point of the rescue code
  49         ;; 0x80000000 if loaded in flash (as it should be)
  50         ;; since etrax actually starts at address 2 when booting from flash, we
  51         ;; put a nop (2 bytes) here first so we dont accidentally skip the di
  52
  53         nop
  54         di
  55 #ifndef CONFIG_SVINTO_SIM
  56         ;; setup port PA and PB default initial directions and data
  57         ;; (so we can flash LEDs, and so that DTR and others are set)
  58
  59         move.b  CONFIG_ETRAX_DEF_R_PORT_PA_DIR, $r0
  60         move.b  $r0, [R_PORT_PA_DIR]
  61         move.b  CONFIG_ETRAX_DEF_R_PORT_PA_DATA, $r0
  62         move.b  $r0, [R_PORT_PA_DATA]
  63
  64         move.b  CONFIG_ETRAX_DEF_R_PORT_PB_DIR, $r0
  65         move.b  $r0, [R_PORT_PB_DIR]
  66         move.b  CONFIG_ETRAX_DEF_R_PORT_PB_DATA, $r0
  67         move.b  $r0, [R_PORT_PB_DATA]
  68
  69         ;; We need to setup the bus registers before we start using the DRAM
  70 #include "../../lib/dram_init.S"
  71
  72 #endif
  73         ;; Setup the stack to a suitably high address.
  74         ;; We assume 8 MB is the minimum DRAM in an eLinux
  75         ;; product and put the sp at the top for now.
  76
  77         move.d  0x40800000, $sp
  78
  79         ;; setup the serial port at 115200 baud
  80
  81         moveq   0, $r0
  82         move.d  $r0, [SERXOFF]
  83
  84         move.b  0x99, $r0
  85         move.b  $r0, [SERBAUD]          ; 115.2kbaud for both transmit and receive
  86
  87         move.b  0x40, $r0               ; rec enable
  88         move.b  $r0, [SERRECC]
  89
  90
  91         moveq   0, $r1          ; "timer" to clock out a LED red flash
  92         move.d  CODE_START, $r3 ; destination counter
  93         move.d  CODE_LENGTH, $r4        ; length
  94         move.d  TIMEOUT_VALUE, $r5      ; "timeout" until jump
  95
  96 wait_ser:
  97         addq    1, $r1
  98         subq    1, $r5          ; decrease timeout
  99         beq     jump_start      ; timed out
 100         nop
 101 #ifndef CONFIG_ETRAX_NO_LEDS
 102 #ifdef CONFIG_ETRAX_PA_LEDS
 103         move.b  CONFIG_ETRAX_DEF_R_PORT_PA_DATA, $r2
 104 #endif
 105 #ifdef CONFIG_ETRAX_PB_LEDS
 106         move.b  CONFIG_ETRAX_DEF_R_PORT_PB_DATA, $r2
 107 #endif
 108         move.d  (1 << CONFIG_ETRAX_LED1R) | (1 << CONFIG_ETRAX_LED2R), $r0
 109         btstq   16, $r1
 110         bpl     1f
 111         nop
 112         or.d    $r0, $r2                ; set bit
 113         ba      2f
 114         nop
 115 1:      not     $r0             ; clear bit
 116         and.d   $r0, $r2
 117 2:
 118 #ifdef CONFIG_ETRAX_PA_LEDS
 119         move.b  $r2, [R_PORT_PA_DATA]
 120 #endif
 121 #ifdef CONFIG_ETRAX_PB_LEDS
 122         move.b  $r2, [R_PORT_PB_DATA]
 123 #endif
 124 #endif
 125
 126         ;; check if we got something on the serial port
 127
 128         move.b  [SERSTAT], $r0
 129         btstq   0, $r0          ; data_avail
 130         bpl     wait_ser
 131         nop
 132
 133         ;; got something - copy the byte and loop
 134
 135         move.b  [SERRDAT], $r0
 136         move.b  $r0, [$r3+]
 137         move.d  TIMEOUT_VALUE, $r5      ; reset "timeout"
 138         subq    1, $r4          ; decrease length
 139         bne     wait_ser
 140         nop
 141 jump_start:
 142         ;; jump into downloaded code
 143
 144         jump    CODE_START