head-nommu.S 2.2 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/mach-types.h>
  18. #include <asm/ptrace.h>
  19. #include <asm/asm-offsets.h>
  20. #include <asm/thread_info.h>
  21. #include <asm/system.h>
  22. /*
  23. * Kernel startup entry point.
  24. * ---------------------------
  25. *
  26. * This is normally called from the decompressor code. The requirements
  27. * are: MMU = off, D-cache = off, I-cache = dont care, r0 = 0,
  28. * r1 = machine nr.
  29. *
  30. * See linux/arch/arm/tools/mach-types for the complete list of machine
  31. * numbers for r1.
  32. *
  33. */
  34. __INIT
  35. .type stext, %function
  36. ENTRY(stext)
  37. msr cpsr_c, #PSR_F_BIT | PSR_I_BIT | SVC_MODE @ ensure svc mode
  38. @ and irqs disabled
  39. #ifndef CONFIG_CPU_CP15
  40. ldr r9, =CONFIG_PROCESSOR_ID
  41. #else
  42. mrc p15, 0, r9, c0, c0 @ get processor id
  43. #endif
  44. bl __lookup_processor_type @ r5=procinfo r9=cpuid
  45. movs r10, r5 @ invalid processor (r5=0)?
  46. beq __error_p @ yes, error 'p'
  47. bl __lookup_machine_type @ r5=machinfo
  48. movs r8, r5 @ invalid machine (r5=0)?
  49. beq __error_a @ yes, error 'a'
  50. ldr r13, __switch_data @ address to jump to after
  51. @ the initialization is done
  52. adr lr, __after_proc_init @ return (PIC) address
  53. add pc, r10, #PROCINFO_INITFUNC
  54. /*
  55. * Set the Control Register and Read the process ID.
  56. */
  57. .type __after_proc_init, %function
  58. __after_proc_init:
  59. #ifdef CONFIG_CPU_CP15
  60. mrc p15, 0, r0, c1, c0, 0 @ read control reg
  61. #ifdef CONFIG_ALIGNMENT_TRAP
  62. orr r0, r0, #CR_A
  63. #else
  64. bic r0, r0, #CR_A
  65. #endif
  66. #ifdef CONFIG_CPU_DCACHE_DISABLE
  67. bic r0, r0, #CR_C
  68. #endif
  69. #ifdef CONFIG_CPU_BPREDICT_DISABLE
  70. bic r0, r0, #CR_Z
  71. #endif
  72. #ifdef CONFIG_CPU_ICACHE_DISABLE
  73. bic r0, r0, #CR_I
  74. #endif
  75. #ifdef CONFIG_CPU_HIGH_VECTOR
  76. orr r0, r0, #CR_V
  77. #else
  78. bic r0, r0, #CR_V
  79. #endif
  80. mcr p15, 0, r0, c1, c0, 0 @ write control reg
  81. #endif /* CONFIG_CPU_CP15 */
  82. mov pc, r13 @ clear the BSS and jump
  83. @ to start_kernel
  84. .ltorg
  85. #include "head-common.S"