begriffs open source - cmsis-freertos/blob - Demo/MCF5235

1 /*

4 This file is part of the FreeRTOS distribution.

6 FreeRTOS is free software; you can redistribute it and/or modify

7 it under the terms of the GNU General Public License** as published by

8 the Free Software Foundation; either version 2 of the License, or

9 (at your option) any later version.

11 FreeRTOS is distributed in the hope that it will be useful,

12 but WITHOUT ANY WARRANTY; without even the implied warranty of

13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

14 GNU General Public License for more details.

16 You should have received a copy of the GNU General Public License

17 along with FreeRTOS; if not, write to the Free Software

18 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

20 A special exception to the GPL can be applied should you wish to distribute

21 a combined work that includes FreeRTOS, without being obliged to provide

22 the source code for any proprietary components. See the licensing section

23 of http://www.FreeRTOS.org for full details of how and when the exception

24 can be applied.

26 ***************************************************************************

27 ***************************************************************************

28 * *

29 * Get the FreeRTOS eBook! See http://www.FreeRTOS.org/Documentation *

30 * *

31 * This is a concise, step by step, 'hands on' guide that describes both *

32 * general multitasking concepts and FreeRTOS specifics. It presents and *

33 * explains numerous examples that are written using the FreeRTOS API. *

34 * Full source code for all the examples is provided in an accompanying *

35 * .zip file. *

36 * *

37 ***************************************************************************

38 ***************************************************************************

40 Please ensure to read the configuration and relevant port sections of the

41 online documentation.

43 http://www.FreeRTOS.org - Documentation, latest information, license and

44 contact details.

46 http://www.SafeRTOS.com - A version that is certified for use in safety

47 critical systems.

49 http://www.OpenRTOS.com - Commercial support, development, porting,

50 licensing and training services.

51 */

53 .title "crt0.S"

55 .extern main

56 .extern __stack

57 .extern __bss_start

58 .extern __text_start

59 .extern init_main

61 .equ MCF5XXX_RAMBAR_SPV, 0x00000200

62 .equ MCF5XXX_RAMBAR_V, 0x00000001

63 .global start

65 .align 4

66 debug:

67 .word 0x2C80 /* write to CSR */

68 .word 0x0010

69 .word 0x0400

70 .word 0x0000

72 start:

73 /* disable all interrupts on startup. */

74 move.w #0x2700, sr

76 /* prepare internal SRAM. */

77 move.l #__SRAM, d0

78 ori.l #( MCF5XXX_RAMBAR_SPV | MCF5XXX_RAMBAR_V ), d0

79 movec d0, rambar

81 /* prepare stack and frame pointer. */

82 move.l #__stack, sp

83 link a6, #-8

85 /* initialize hardware. */

86 jsr init_main

88 /* zero out the bss section. */

89 move.l #__bss_start, d1

90 move.l #_end, d0

91 cmp.l d0, d1

92 jbeq 3f

93 move.l d1, a0

94 sub.l d1, d0

95 subq.l #1, d0

96 2:

97 clr.b (a0)+

98 subq.l #1, d0

99 jbpl 2b

100 3:

101

102 /* Relocate the data section. */

103 move.l #__data_load_start, %a0 /* .data in ROM */

104 move.l #copy_start, %a1 /* .data in RAM */

105

106 /* Test if the two sections overlap. This is the case when we are working

107 * with the debugger and the debugger loads the .data section.

108 */

109 cmpa.l %a0, %a1

110 beq 2f

111 1:

112 /* Have we already copied everything. */

113 cmpa.l #__data_load_end, %a0

114 beq 2f

115 move.b (%a0)+, (%a1)+

116 bra 1b

117

118 2:

119

120 /* C library */

121 move.l #__FINI_SECTION__, -(%sp)

122 jsr atexit

123 jsr __INIT_SECTION__

124

125 /* call main(int argc, char *argv[] */

126 move.l #0, -(sp)

127 move.l #0, -(sp)

128 move.l #0, -(sp)

129 jsr main

130 lea (sp, 12), %sp

131

132 /* stop on exit from main. */

133 1:

134 halt

135