env/v/entry.S

   1 #include "riscv_test.h"
   2
   3 #ifdef __riscv64
   4 # define STORE    sd
   5 # define LOAD     ld
   6 # define REGBYTES 8
   7 #else
   8 # define STORE    sw
   9 # define LOAD     lw
  10 # define REGBYTES 4
  11 #endif
  12
  13   .text
  14   .global _start
  15 _start:
  16   la sp, stack_top
  17   li a1, 1337
  18   la a0, userstart
  19   j vm_boot
  20
  21 save_tf:  # write the trap frame onto the stack
  22
  23   # save gprs
  24   STORE  x3,3*REGBYTES(x2)
  25   STORE  x4,4*REGBYTES(x2)
  26   STORE  x5,5*REGBYTES(x2)
  27   STORE  x6,6*REGBYTES(x2)
  28   STORE  x7,7*REGBYTES(x2)
  29   STORE  x8,8*REGBYTES(x2)
  30   STORE  x9,9*REGBYTES(x2)
  31   STORE  x10,10*REGBYTES(x2)
  32   STORE  x11,11*REGBYTES(x2)
  33   STORE  x12,12*REGBYTES(x2)
  34   STORE  x13,13*REGBYTES(x2)
  35   STORE  x14,14*REGBYTES(x2)
  36   STORE  x15,15*REGBYTES(x2)
  37   STORE  x16,16*REGBYTES(x2)
  38   STORE  x17,17*REGBYTES(x2)
  39   STORE  x18,18*REGBYTES(x2)
  40   STORE  x19,19*REGBYTES(x2)
  41   STORE  x20,20*REGBYTES(x2)
  42   STORE  x21,21*REGBYTES(x2)
  43   STORE  x22,22*REGBYTES(x2)
  44   STORE  x23,23*REGBYTES(x2)
  45   STORE  x24,24*REGBYTES(x2)
  46   STORE  x25,25*REGBYTES(x2)
  47   STORE  x26,26*REGBYTES(x2)
  48   STORE  x27,27*REGBYTES(x2)
  49   STORE  x28,28*REGBYTES(x2)
  50   STORE  x29,29*REGBYTES(x2)
  51   STORE  x30,30*REGBYTES(x2)
  52   STORE  x31,31*REGBYTES(x2)
  53
  54   mfpcr  x3,sup0
  55   STORE  x3,1*REGBYTES(x2)          # x1 is in PCR_K0
  56   mfpcr  x3,sup1
  57   STORE  x3,2*REGBYTES(x2)          # x2 is in PCR_K1
  58
  59   # get sr, epc, badvaddr, cause
  60   mfpcr  x3,status          # sr
  61   STORE  x3,32*REGBYTES(x2)
  62   mfpcr  x4,epc          # epc
  63   STORE  x4,33*REGBYTES(x2)
  64   mfpcr  x3,badvaddr      # badvaddr
  65   STORE  x3,34*REGBYTES(x2)
  66   mfpcr  x3,cause        # cause
  67   STORE  x3,35*REGBYTES(x2)
  68
  69   # get faulting insn, if it wasn't a fetch-related trap
  70   li    x5, CAUSE_MISALIGNED_FETCH
  71   li    x6, CAUSE_FAULT_FETCH
  72   beq   x3, x5, 1f
  73   beq   x3, x6, 1f
  74   lh    x5,0(x4)
  75   lh    x6,2(x4)
  76   sh    x5,  36*REGBYTES(x2)
  77   sh    x6,2+36*REGBYTES(x2)
  78 1:
  79
  80   bge   x3, x0, 1f
  81   vxcptcause x3
  82   STORE  x3,37*REGBYTES(x2)
  83 1:
  84
  85   ret
  86
  87   .globl  pop_tf
  88 pop_tf:  # write the trap frame onto the stack
  89   # restore gprs
  90   LOAD  a1,32*REGBYTES(a0)  # restore sr (should disable interrupts)
  91   mtpcr  a1,status
  92
  93   LOAD  x1,1*REGBYTES(a0)
  94   mtpcr  x1,sup0
  95   LOAD  x1,2*REGBYTES(a0)
  96   mtpcr x1,sup1
  97   move  x1,a0
  98   LOAD  x3,3*REGBYTES(x1)
  99   LOAD  x4,4*REGBYTES(x1)
 100   LOAD  x5,5*REGBYTES(x1)
 101   LOAD  x6,6*REGBYTES(x1)
 102   LOAD  x7,7*REGBYTES(x1)
 103   LOAD  x8,8*REGBYTES(x1)
 104   LOAD  x9,9*REGBYTES(x1)
 105   LOAD  x10,10*REGBYTES(x1)
 106   LOAD  x11,11*REGBYTES(x1)
 107   LOAD  x12,12*REGBYTES(x1)
 108   LOAD  x13,13*REGBYTES(x1)
 109   LOAD  x14,14*REGBYTES(x1)
 110   LOAD  x15,15*REGBYTES(x1)
 111   LOAD  x16,16*REGBYTES(x1)
 112   LOAD  x17,17*REGBYTES(x1)
 113   LOAD  x18,18*REGBYTES(x1)
 114   LOAD  x19,19*REGBYTES(x1)
 115   LOAD  x20,20*REGBYTES(x1)
 116   LOAD  x21,21*REGBYTES(x1)
 117   LOAD  x22,22*REGBYTES(x1)
 118   LOAD  x23,23*REGBYTES(x1)
 119   LOAD  x24,24*REGBYTES(x1)
 120   LOAD  x25,25*REGBYTES(x1)
 121   LOAD  x26,26*REGBYTES(x1)
 122   LOAD  x27,27*REGBYTES(x1)
 123   LOAD  x28,28*REGBYTES(x1)
 124   LOAD  x29,29*REGBYTES(x1)
 125   LOAD  x30,30*REGBYTES(x1)
 126   LOAD  x31,31*REGBYTES(x1)
 127
 128   # gtfo!
 129   LOAD  x2,33*REGBYTES(x1)
 130   mtpcr x2,epc
 131   mfpcr x1,sup0
 132   mfpcr x2,sup1
 133   eret
 134
 135   .global  trap_entry
 136 trap_entry:
 137   mtpcr ra,sup0
 138   mtpcr x2,sup1
 139
 140   # coming from kernel?
 141   mfpcr ra,status
 142   and   ra,ra,SR_PS
 143   bnez  ra, 1f
 144
 145   # no, so start at the top of the stack
 146   la    x2,stack_top+MAX_TEST_PAGES*PGSIZE-SIZEOF_TRAPFRAME_T
 147   jal   save_tf
 148   move  sp,x2
 149   setpcr status, SR_EI
 150   move  a0,x2
 151   mfpcr ra,status
 152   and   ra,ra,SR_EA
 153   beqz  ra, 2f
 154   addi  x2,x2,38*REGBYTES
 155   vxcptsave x2
 156 2:jal   handle_trap
 157
 158   # when coming from kernel, continue below its stack
 159 1:li x2,17712
 160   sub   x2, sp, x2
 161   jal   save_tf
 162   move  sp,x2
 163   setpcr status, SR_EI
 164   move  a0,x2
 165   jal   handle_trap
 166
 167   .bss
 168   .global stack_bot
 169   .global stack_top
 170 stack_bot:
 171   .skip  32768
 172 stack_top: