1 | /* Startup code for M68HC11/M68HC12. |
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2 | * Copyright (C) 1999, 2000, 2001, 2002 Stephane Carrez (stcarrez@nerim.fr) |
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3 | * |
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4 | * The authors hereby grant permission to use, copy, modify, distribute, |
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5 | * and license this software and its documentation for any purpose, provided |
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6 | * that existing copyright notices are retained in all copies and that this |
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7 | * notice is included verbatim in any distributions. No written agreement, |
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8 | * license, or royalty fee is required for any of the authorized uses. |
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9 | * Modifications to this software may be copyrighted by their authors |
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10 | * and need not follow the licensing terms described here, provided that |
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11 | * the new terms are clearly indicated on the first page of each file where |
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12 | * they apply. |
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13 | */ |
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14 | |
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15 | ;----------------------------------------- |
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16 | ; startup code |
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17 | ;----------------------------------------- |
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18 | .file "crt0.s" |
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19 | |
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20 | ;; |
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21 | ;; |
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22 | ;; The linker concatenate the .install* sections in the following order: |
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23 | ;; |
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24 | ;; .install0 Setup the stack pointer |
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25 | ;; .install1 Place holder for applications |
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26 | ;; .install2 Optional installation of data section in memory |
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27 | ;; .install3 Place holder for applications |
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28 | ;; .install4 Invokes the main |
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29 | ;; |
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30 | .sect .install0,"ax",@progbits |
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31 | .globl _start |
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32 | |
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33 | _start: |
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34 | ;; |
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35 | ;; At this step, the stack is not initialized and interrupts are masked. |
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36 | ;; Applications only have 64 cycles to initialize some registers. |
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37 | ;; |
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38 | ;; To have a generic/configurable startup, initialize the stack to |
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39 | ;; the end of some memory region. The _stack symbol is defined by |
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40 | ;; the linker. |
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41 | ;; |
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42 | lds #_stack |
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43 | |
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44 | .sect .install2,"ax",@progbits |
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45 | ;; |
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46 | ;; Call a specific initialization operation. The default is empty. |
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47 | ;; It can be overriden by applications. It is intended to initialize |
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48 | ;; the 68hc11 registers. Function prototype is: |
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49 | ;; |
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50 | ;; int __premain(void); |
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51 | ;; |
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52 | jsr __premain |
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53 | |
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54 | ;; |
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55 | ;; |
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56 | ;; |
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57 | .sect .install4,"ax",@progbits |
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58 | jsr main |
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59 | fatal: |
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60 | jsr exit |
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61 | bra fatal |
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62 | |
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63 | ;----------------------------------------- |
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64 | ; end startup code |
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65 | ;----------------------------------------- |
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66 | ;; Force loading of data section mapping and bss clear |
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67 | .globl __map_data_section |
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68 | .globl __init_bss_section |
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69 | |
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