call_o32.S 2.6 KB

1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889909192939495
  1. /*
  2. * O32 interface for the 64 (or N32) ABI.
  3. *
  4. * Copyright (C) 2002 Maciej W. Rozycki
  5. *
  6. * This program is free software; you can redistribute it and/or
  7. * modify it under the terms of the GNU General Public License
  8. * as published by the Free Software Foundation; either version
  9. * 2 of the License, or (at your option) any later version.
  10. */
  11. #include <asm/asm.h>
  12. #include <asm/regdef.h>
  13. /* Maximum number of arguments supported. Must be even! */
  14. #define O32_ARGC 32
  15. /* Number of static registers we save. */
  16. #define O32_STATC 11
  17. /* Frame size for static register */
  18. #define O32_FRAMESZ (SZREG * O32_STATC)
  19. /* Frame size on new stack */
  20. #define O32_FRAMESZ_NEW (SZREG + 4 * O32_ARGC)
  21. .text
  22. /*
  23. * O32 function call dispatcher, for interfacing 32-bit ROM routines.
  24. *
  25. * The standard 64 (N32) calling sequence is supported, with a0
  26. * holding a function pointer, a1 a new stack pointer, a2-a7 -- its
  27. * first six arguments and the stack -- remaining ones (up to O32_ARGC,
  28. * including a2-a7). Static registers, gp and fp are preserved, v0 holds
  29. * a result. This code relies on the called o32 function for sp and ra
  30. * restoration and this dispatcher has to be placed in a KSEGx (or KUSEG)
  31. * address space. Any pointers passed have to point to addresses within
  32. * one of these spaces as well.
  33. */
  34. NESTED(call_o32, O32_FRAMESZ, ra)
  35. REG_SUBU sp,O32_FRAMESZ
  36. REG_S ra,O32_FRAMESZ-1*SZREG(sp)
  37. REG_S fp,O32_FRAMESZ-2*SZREG(sp)
  38. REG_S gp,O32_FRAMESZ-3*SZREG(sp)
  39. REG_S s7,O32_FRAMESZ-4*SZREG(sp)
  40. REG_S s6,O32_FRAMESZ-5*SZREG(sp)
  41. REG_S s5,O32_FRAMESZ-6*SZREG(sp)
  42. REG_S s4,O32_FRAMESZ-7*SZREG(sp)
  43. REG_S s3,O32_FRAMESZ-8*SZREG(sp)
  44. REG_S s2,O32_FRAMESZ-9*SZREG(sp)
  45. REG_S s1,O32_FRAMESZ-10*SZREG(sp)
  46. REG_S s0,O32_FRAMESZ-11*SZREG(sp)
  47. move jp,a0
  48. REG_SUBU s0,a1,O32_FRAMESZ_NEW
  49. REG_S sp,O32_FRAMESZ_NEW-1*SZREG(s0)
  50. sll a0,a2,zero
  51. sll a1,a3,zero
  52. sll a2,a4,zero
  53. sll a3,a5,zero
  54. sw a6,0x10(s0)
  55. sw a7,0x14(s0)
  56. PTR_LA t0,O32_FRAMESZ(sp)
  57. PTR_LA t1,0x18(s0)
  58. li t2,O32_ARGC-6
  59. 1:
  60. lw t3,(t0)
  61. REG_ADDU t0,SZREG
  62. sw t3,(t1)
  63. REG_SUBU t2,1
  64. REG_ADDU t1,4
  65. bnez t2,1b
  66. move sp,s0
  67. jalr jp
  68. REG_L sp,O32_FRAMESZ_NEW-1*SZREG(sp)
  69. REG_L s0,O32_FRAMESZ-11*SZREG(sp)
  70. REG_L s1,O32_FRAMESZ-10*SZREG(sp)
  71. REG_L s2,O32_FRAMESZ-9*SZREG(sp)
  72. REG_L s3,O32_FRAMESZ-8*SZREG(sp)
  73. REG_L s4,O32_FRAMESZ-7*SZREG(sp)
  74. REG_L s5,O32_FRAMESZ-6*SZREG(sp)
  75. REG_L s6,O32_FRAMESZ-5*SZREG(sp)
  76. REG_L s7,O32_FRAMESZ-4*SZREG(sp)
  77. REG_L gp,O32_FRAMESZ-3*SZREG(sp)
  78. REG_L fp,O32_FRAMESZ-2*SZREG(sp)
  79. REG_L ra,O32_FRAMESZ-1*SZREG(sp)
  80. REG_ADDU sp,O32_FRAMESZ
  81. jr ra
  82. END(call_o32)