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     TRAP(0xC00, None)
  22
  23 Special Registers Altered:
  24
  25     SRR0 SRR1 MSR
  26
  27 # System Call Vectored
  28
  29 SC-Form
  30
  31 * scv LEV
  32
  33 Pseudo-code:
  34
  35     LR <- CIA + 4
  36     SRR1[33:36] <- undefined([0]*4)
  37     SRR1[42:47] <- undefined([0]*6)
  38     SRR1[0:32]  <- MSR[0:32]
  39     SRR1[37:41] <- MSR[37:41]
  40     SRR1[48:63] <- MSR[48:63]
  41     MSR <- new_value
  42     NIA <- vectored
  43
  44 Special Registers Altered:
  45
  46     LR CTR MSR
  47
  48 # Return From System Call Vectored
  49
  50 XL-Form
  51
  52 * rfscv
  53
  54 Pseudo-code:
  55
  56     if (MSR[29:31] != 0b010) | (CTR[29:31] != 0b000) then
  57         MSR[29:31] <- CTR[29:31]
  58     MSR[48] <- CTR[49]
  59     MSR[58] <- CTR[49]
  60     MSR[59] <- CTR[49]
  61     MSR[0:2] <- CTR[0:2]
  62     MSR[4:28] <- CTR[4:28]
  63     MSR[32] <- CTR[32]
  64     MSR[37:41] <- CTR[37:41]
  65     MSR[49:50] <- CTR[49:50]
  66     MSR[52:57] <- CTR[52:57]
  67     MSR[60:63] <- CTR[60:63]
  68     NIA <-iea LR[0:61] || 0b00
  69
  70 Special Registers Altered:
  71
  72     MSR
  73
  74 # Return From Interrupt Doubleword
  75
  76 XL-Form
  77
  78 * rfid
  79
  80 Pseudo-code:
  81
  82     MSR[51] <- (MSR[3] & SRR1[51]) | ((¬MSR[3] & MSR[51]))
  83     MSR[3] <- (MSR[3] & SRR1[3])
  84     if (MSR[29:31] != 0b010) | (SRR1[29:31] != 0b000) then
  85         MSR[29:31] <- SRR1[29:31]
  86     MSR[48] <- SRR1[48] | SRR1[49]
  87     MSR[58] <- SRR1[58] | SRR1[49]
  88     MSR[59] <- SRR1[59] | SRR1[49]
  89     MSR[0:2] <- SRR1[0:2]
  90     MSR[4:28] <- SRR1[4:28]
  91     MSR[32] <- SRR1[32]
  92     MSR[37:41] <- SRR1[37:41]
  93     MSR[49:50] <- SRR1[49:50]
  94     MSR[52:57] <- SRR1[52:57]
  95     MSR[60:63] <- SRR1[60:63]
  96     NIA <-iea SRR0[0:61] || 0b00
  97
  98 Special Registers Altered:
  99
 100     MSR
 101
 102 # Hypervisor Return From Interrupt Doubleword
 103
 104 XL-Form
 105
 106 * hrfid
 107
 108 Pseudo-code:
 109
 110     if (MSR[29:31] != 0b010) | (HSRR1[29:31] != 0b000) then
 111         MSR[29:31] <- HSRR1[29:31]
 112     MSR[48] <- HSRR1[48] | HSRR1[49]
 113     MSR[58] <- HSRR1[58] | HSRR1[49]
 114     MSR[59] <- HSRR1[59] | HSRR1[49]
 115     MSR[0:28] <- HSRR1[0:28]
 116     MSR[32] <- HSRR1[32]
 117     MSR[37:41] <- HSRR1[37:41]
 118     MSR[49:57] <- HSRR1[49:57]
 119     MSR[60:63] <- HSRR1[60:63]
 120     NIA <-iea HSRR0[0:61] || 0b00
 121
 122 Special Registers Altered:
 123
 124     MSR
 125
 126 <!-- Checked March 2021 -->