head-nommu.S 2.1 KB

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  1. /*
  2. * linux/arch/arm/kernel/head-nommu.S
  3. *
  4. * Copyright (C) 1994-2002 Russell King
  5. * Copyright (C) 2003-2006 Hyok S. Choi
  6. *
  7. * This program is free software; you can redistribute it and/or modify
  8. * it under the terms of the GNU General Public License version 2 as
  9. * published by the Free Software Foundation.
  10. *
  11. * Common kernel startup code (non-paged MM)
  12. *
  13. */
  14. #include <linux/linkage.h>
  15. #include <linux/init.h>
  16. #include <asm/assembler.h>
  17. #include <asm/ptrace.h>
  18. #include <asm/asm-offsets.h>
  19. #include <asm/thread_info.h>
  20. #include <asm/system.h>
  21. /*
  22. * Kernel startup entry point.
  23. * ---------------------------
  24. *
  25. * This is normally called from the decompressor code. The requirements
  26. * are: MMU = off, D-cache = off, I-cache = dont care, r0 = 0,
  27. * r1 = machine nr.
  28. *
  29. * See linux/arch/arm/tools/mach-types for the complete list of machine
  30. * numbers for r1.
  31. *
  32. */
  33. __HEAD
  34. ENTRY(stext)
  35. setmode PSR_F_BIT | PSR_I_BIT | SVC_MODE, r9 @ ensure svc mode
  36. @ and irqs disabled
  37. #ifndef CONFIG_CPU_CP15
  38. ldr r9, =CONFIG_PROCESSOR_ID
  39. #else
  40. mrc p15, 0, r9, c0, c0 @ get processor id
  41. #endif
  42. bl __lookup_processor_type @ r5=procinfo r9=cpuid
  43. movs r10, r5 @ invalid processor (r5=0)?
  44. beq __error_p @ yes, error 'p'
  45. adr lr, BSYM(__after_proc_init) @ return (PIC) address
  46. ARM( add pc, r10, #PROCINFO_INITFUNC )
  47. THUMB( add r12, r10, #PROCINFO_INITFUNC )
  48. THUMB( mov pc, r12 )
  49. ENDPROC(stext)
  50. /*
  51. * Set the Control Register and Read the process ID.
  52. */
  53. __after_proc_init:
  54. #ifdef CONFIG_CPU_CP15
  55. /*
  56. * CP15 system control register value returned in r0 from
  57. * the CPU init function.
  58. */
  59. #ifdef CONFIG_ALIGNMENT_TRAP
  60. orr r0, r0, #CR_A
  61. #else
  62. bic r0, r0, #CR_A
  63. #endif
  64. #ifdef CONFIG_CPU_DCACHE_DISABLE
  65. bic r0, r0, #CR_C
  66. #endif
  67. #ifdef CONFIG_CPU_BPREDICT_DISABLE
  68. bic r0, r0, #CR_Z
  69. #endif
  70. #ifdef CONFIG_CPU_ICACHE_DISABLE
  71. bic r0, r0, #CR_I
  72. #endif
  73. #ifdef CONFIG_CPU_HIGH_VECTOR
  74. orr r0, r0, #CR_V
  75. #else
  76. bic r0, r0, #CR_V
  77. #endif
  78. mcr p15, 0, r0, c1, c0, 0 @ write control reg
  79. #endif /* CONFIG_CPU_CP15 */
  80. b __mmap_switched @ clear the BSS and jump
  81. @ to start_kernel
  82. ENDPROC(__after_proc_init)
  83. .ltorg
  84. #include "head-common.S"