openpower/isa/system.mdwn

   1 <!-- Instructions here described in PowerISA Version 3.0 B Book 1 -->
   2
   3 <!-- 3.3.1 System Linkage Instructions Page 952 - 956 -->
   4
   5 <!-- These instructions provide the means by which a program can call upon the system to perform a service. -->
   6
   7 # System Call
   8
   9 SC-Form
  10
  11 * sc LEV
  12
  13 Pseudo-code:
  14
  15     SRR0 <-iea CIA + 4
  16     SRR1[33:36] <- 0
  17     SRR1[42:47] <- 0
  18     SRR1[0:32]  <- MSR[0:32]
  19     SRR1[37:41] <- MSR[37:41]
  20     SRR1[48:63] <- MSR[48:63]
  21     MSR <- new_value
  22     NIA <- 0x0000_0000_0000_0C00
  23
  24 Special Registers Altered:
  25
  26     SRR0 SRR1 MSR
  27
  28 # System Call Vectored
  29
  30 SC-Form
  31
  32 * scv LEV
  33
  34 Pseudo-code:
  35
  36     LR <- CIA + 4
  37     SRR1[33:36] <- undefined([0]*4)
  38     SRR1[42:47] <- undefined([0]*6)
  39     SRR1[0:32]  <- MSR[0:32]
  40     SRR1[37:41] <- MSR[37:41]
  41     SRR1[48:63] <- MSR[48:63]
  42     MSR <- new_value
  43     NIA <- vectored
  44
  45 Special Registers Altered:
  46
  47     LR CTR MSR
  48
  49 # Return From System Call Vectored
  50
  51 XL-Form
  52
  53 * rfscv
  54
  55 Pseudo-code:
  56
  57     if (MSR[29:31] != 0b010) | (CTR[29:31] != 0b000) then
  58         MSR[29:31] <- CTR[29:31]
  59     MSR[48] <- CTR[49]
  60     MSR[58] <- CTR[49]
  61     MSR[59] <- CTR[49]
  62     MSR[0:2] <- CTR[0:2]
  63     MSR[4:28] <- CTR[4:28]
  64     MSR[32] <- CTR[32]
  65     MSR[37:41] <- CTR[37:41]
  66     MSR[49:50] <- CTR[49:50]
  67     MSR[52:57] <- CTR[52:57]
  68     MSR[60:63] <- CTR[60:63]
  69     NIA <-iea LR[0:61] || 0b00
  70
  71 Special Registers Altered:
  72
  73     MSR
  74
  75 # Return From Interrupt Doubleword
  76
  77 XL-Form
  78
  79 * rfid
  80
  81 Pseudo-code:
  82
  83     MSR[51] <- (MSR[3] & SRR1[51]) | ((¬MSR[3] & MSR[51]))
  84     MSR[3] <- (MSR[3] & SRR1[3])
  85     if (MSR[29:31] != 0b010) | (SRR1[29:31] != 0b000) then
  86         MSR[29:31] <- SRR1[29:31]
  87     MSR[48] <- SRR1[48] | SRR1[49]
  88     MSR[58] <- SRR1[58] | SRR1[49]
  89     MSR[59] <- SRR1[59] | SRR1[49]
  90     MSR[0:2] <- SRR1[0:2]
  91     MSR[4:28] <- SRR1[4:28]
  92     MSR[32] <- SRR1[32]
  93     MSR[37:41] <- SRR1[37:41]
  94     MSR[49:50] <- SRR1[49:50]
  95     MSR[52:57] <- SRR1[52:57]
  96     MSR[60:63] <- SRR1[60:63]
  97     NIA <-iea SRR0[0:61] || 0b00
  98
  99 Special Registers Altered:
 100
 101     MSR
 102
 103 # Hypervisor Return From Interrupt Doubleword
 104
 105 XL-Form
 106
 107 * hrfid
 108
 109 Pseudo-code:
 110
 111     if (MSR[29:31] != 0b010) | (HSRR1[29:31] != 0b000) then
 112         MSR[29:31] <- HSRR1[29:31]
 113     MSR[48] <- HSRR1[48] | HSRR1[49]
 114     MSR[58] <- HSRR1[58] | HSRR1[49]
 115     MSR[59] <- HSRR1[59] | HSRR1[49]
 116     MSR[0:28] <- HSRR1[0:28]
 117     MSR[32] <- HSRR1[32]
 118     MSR[37:41] <- HSRR1[37:41]
 119     MSR[49:57] <- HSRR1[49:57]
 120     MSR[60:63] <- HSRR1[60:63]
 121     NIA <-iea HSRR0[0:61] || 0b00
 122
 123 Special Registers Altered:
 124
 125     MSR
 126
 127 <!-- Checked March 2021 -->