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Author SHA1 Message Date
Elyan
98ec2dd0f4 Added ldrh and ldrc instructions
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Details
2024-11-11 14:38:40 +01:00
Elyan
90fec87ccb Modified A1, B1 and C encodings to remove the condition field 2024-11-11 12:00:43 +01:00
12 changed files with 281 additions and 289 deletions
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12
src/execution-engine-spec/instruction-formats.adoc
View File

@ -2,11 +2,11 @@
....
{reg: [
{bits: 7, name: 'opcode', type: 8},
{bits: 4, name: 'cond', type: 6},
{bits: 4, name: 'imm[3:0]', type: 5},
{bits: 5, name: 'rd', type: 2},
{bits: 5, name: 'rs1', type: 4},
{bits: 5, name: 'rs2', type: 4},
{bits: 6, name: 'imm', type: 5}
{bits: 6, name: 'imm[9:4]', type: 5}
], config: {label: {right: 'A1-Type'}}}
....
@ -26,10 +26,10 @@
....
{reg: [
{bits: 7, name: 'opcode', type: 8},
{bits: 4, name: 'cond', type: 6},
{bits: 4, name: 'imm[3:0]', type: 5},
{bits: 5, name: 'rd', type: 2},
{bits: 5, name: 'rs1', type: 4},
{bits: 11, name: 'imm', type: 5}
{bits: 11, name: 'imm[14:4]', type: 5}
], config: {label: {right: 'B1-Type'}}}
....
@ -48,9 +48,9 @@
....
{reg: [
{bits: 7, name: 'opcode', type: 8},
{bits: 4, name: 'cond', type: 6},
{bits: 4, name: 'imm[3:0]', type: 5},
{bits: 5, name: 'rd', type: 2},
{bits: 16, name: 'imm', type: 5}
{bits: 16, name: 'imm[19:4]', type: 5}
], config: {label: {right: 'C-Type'}}}
....

34
src/execution-engine-spec/instructions-operands-encoding.adoc
View File

@ -10,97 +10,97 @@
|0000~2~
|0000~16~
|AL
|al
|Always
|_None_
|0001~2~
|0001~16~
|EQ
|eq
|Equal
|Z==1
|0010~2~
|0002~16~
|NEQ
|ne
|Not Equal
|Z==0
.2+|0011~2~
.2+|0003~16~
|UGE
|ge
|Unsigned Greater or Equal
.2+|C==1
<|CS
<|cs
<|Carry Set
.2+|0100~2~
.2+|0004~16~
|ULT
|lt
|Unsigned Lower Than
.2+|C==0
<|CC
<|cc
<|Carry Clear
|0101~2~
|0005~16~
|NEG
|neg
|Negative
|N==1
|0110~2~
|0006~16~
|POS
|pos
|Positive
|N==0
|0111~2~
|0007~16~
|VS
|vs
|oVerflow Set
|V==1
|1000~2~
|0008~16~
|VC
|vc
|oVerflow Clear
|V==0
|1001~2~
|0009~16~
|UGT
|gt
|Unsigned Greater Than
|C==1 && Z==0
|1010~2~
|000a~16~
|ULE
|le
|Unsigned Lower or Equal
|C==0 && Z==1
|1011~2~
|000b~16~
|SGE
|sge
|Signed Greater or Equal
|N==V
|1100~2~
|000c~16~
|SLT
|slt
|Signed Lower Than
|N!=V
|1101~2~
|000d~16~
|SGT
|sgt
|Signed Greater Than
|Z==0 && N==V
|1110~2~
|000e~16~
|SLE
|sle
|Signed Lower or Equal
|Z==1 && N!=V

4
src/execution-engine-spec/instructions.adoc
View File

@ -30,6 +30,10 @@ include::instructions/svc.adoc[]
<<<
==== Memory-Related Instructions
include::instructions/ldr.adoc[]
<<<
include::instructions/ldrh.adoc[]
<<<
include::instructions/ldrc.adoc[]
<<<
==== Register Manipulation Instructions

13
src/execution-engine-spec/instructions/b.adoc
View File

@ -33,7 +33,7 @@
====== BIO: Branch Immediate Offset
Description::
Branch to the instruction the address of which is at `pc + off`. +
The assembler selects this variant over *BAIO* when a condition is given.
The assembler selects this variant over *BAIO* when a condition other than `al` is given.
Encoding:: D1-Type
Assembler syntax::
+
@ -53,10 +53,10 @@ Examples::
+
[source]
----
b.al -20 <1>
b.ne -20 <1>
b.eq 8 <2>
----
<1> Branches to `pc - 20`.
<1> If the last comparison resulted in an 'ne' condition status, branches to `pc - 20`. Else, does nothing.
<2> If the last comparison resulted in an 'eq' condition status, branches to `pc + 8`. Else, does nothing.
Privileged instruction:: No.
@ -70,17 +70,18 @@ Exceptions::
Description::
Branch to the instruction the address of which is at `pc + off`.
Permits the use of more bits for the offset at the cost of being unconditional. +
The assembler selects this variant over *BIO* when no condition is given.
The assembler selects this variant over *BIO* when no condition is given (or when `al` is given).
Encoding:: D2-Type
Assembler syntax::
+
[source]
----
b <off>
b<cond>? <off>
----
+
Where:
[horizontal]
cond::: Optional condition (if specified, can only be `al`).
off:::
Signed immediate offset.
Must be in the range -8388611..8388607.
@ -90,8 +91,10 @@ Examples::
[source]
----
b -0x3FFFFF <1>
b.al 0x3FFFFF <2>
----
<1> Branches to `pc - 0x3FFFFF`.
<2> Branches to `pc + 0x3FFFFF`.
Privileged instruction:: No.
Updates program state flags:: No.

244
src/execution-engine-spec/instructions/ldr.adoc
View File

@ -3,40 +3,18 @@
....
{reg: [
{bits: 7, name: 0x1, type: 8, attr: '0x01'},
{bits: 4, name: 'cond', type: 6},
{bits: 4, name: 'off[3:0]', type: 5},
{bits: 5, name: 'dst', type: 2},
{bits: 5, name: 'src', type: 4},
{bits: 11, name: 'off', type: 5}
], config: {label: {right: 'LDRIR'}}}
....
[wavedrom, ,svg]
....
{reg: [
{bits: 7, name: 0x2, type: 8, attr: '0x02'},
{bits: 4, name: 'cond', type: 6},
{bits: 5, name: 'dst', type: 2},
{bits: 5, name: 'src', type: 4},
{bits: 11, name: 'off', type: 5}
], config: {label: {right: 'LDRIRW'}}}
....
[wavedrom, ,svg]
....
{reg: [
{bits: 7, name: 0x3, type: 8, attr: '0x03'},
{bits: 4, name: 'cond', type: 6},
{bits: 5, name: 'dst', type: 2},
{bits: 5, name: 'src', type: 4},
{bits: 11, name: 'off', type: 5}
], config: {label: {right: 'LDRIOW'}}}
{bits: 11, name: 'off[14:4]', type: 5}
], config: {label: {right: 'LDRI'}}}
....
[wavedrom, ,svg]
....
{reg: [
{bits: 7, name: 0x4, type: 8, attr: '0x04'},
{bits: 4, name: 'cond', type: 6},
{bits: 4, name: 'unused'},
{bits: 5, name: 'dst', type: 2},
{bits: 5, name: 'src', type: 4},
{bits: 5, name: 'off', type: 4},
@ -44,56 +22,20 @@
], config: {label: {right: 'LDRR'}}}
....
[wavedrom, ,svg]
....
{reg: [
{bits: 7, name: 0x5, type: 8, attr: '0x05'},
{bits: 4, name: 'cond', type: 6},
{bits: 5, name: 'dst', type: 2},
{bits: 5, name: 'src', type: 4},
{bits: 5, name: 'off', type: 4},
{bits: 6, name: 'unused'}
], config: {label: {right: 'LDRRW'}}}
....
[wavedrom, ,svg]
....
{reg: [
{bits: 7, name: 0x6, type: 8, attr: '0x06'},
{bits: 4, name: 'cond', type: 6},
{bits: 5, name: 'dst', type: 2},
{bits: 5, name: 'src', type: 4},
{bits: 5, name: 'off', type: 4},
{bits: 6, name: 'unused'}
], config: {label: {right: 'LDROW'}}}
....
[frame=ends,grid=rows,cols="1,1"]
|===
|Instruction variant | Description
|LDRIR
|<<LDRIR>>
|LDRIRW
|<<LDRIRW>>
|LDRIOW
|<<LDRIOW>>
|LDRI
|<<LDRI>>
|LDRR
|<<LDRR>>
|LDRRW
|<<LDRRW>>
|LDROW
|<<LDROW>>
|===
<<<
[id=LDRIR]
====== LDRIR: Load Register+Immediate Pre-indexed
[id=LDRI]
====== LDRI: Load Register+Immediate
Description::
Loads a word from memory into a register.
The immediate offset `off` is added to the address in the `src` register before reading memory.
@ -102,17 +44,16 @@ Assembler syntax::
+
[source]
----
ldr<cond?> <dst>, [<src>, <off?>]
ldr <dst>, [<src>, <off?>]
----
+
Where:
[horizontal]
cond::: Optional condition.
dst::: Destination register.
src::: Source register.
off:::
Optional offset immediate.
Must be a multiple of 4 and in the range -4096..4092.
Must be a multiple of 4 and in the range -65536..65532.
If omitted, then 0 is used.
Examples::
@ -121,93 +62,9 @@ Examples::
----
ldr r1, [r0] <1>
ldr r3, [r2, 8] <2>
ldr.eq r5, [r4] <3>
----
<1> Reads a word from the memory address in r0 into r1.
<2> Reads a word from the memory address in r2, with an 8 bytes offset, into r3.
<3> If the last comparison resulted in an 'eq' condition status, reads a word from the memory address in r4 into r5. Else, does nothing.
Privileged instruction:: No.
Updates program state flags:: No.
Exceptions::
MemFault.
<<<
[id=LDRIRW]
====== LDRIRW: Load Register+Immediate Pre-indexed with Write-back
Description::
Increments the source register then reads a word from memory into the destination register.
The immediate offset `off` is added to the `src` register value before reading a word from memory into the `dst` register.
Encoding:: B1-Type
Assembler syntax::
+
[source]
----
ldr<cond?> <dst>, ![<src>, <off?>]
----
+
Where:
[horizontal]
cond::: Optional condition.
dst::: Destination register.
src::: Source register.
off:::
Optional offset immediate.
Must be a multiple of 4 and in the range -4096..4092.
If omitted, then 4 is used.
Examples::
+
[source]
----
ldr r1, ![r0] <1>
ldr r3, ![r2, 8] <2>
ldr.eq r5, ![r4] <3>
----
<1> Increments r0 by 4 then reads a word from the memory address in r0 into r1.
<2> Increments r2 by 8 then reads a word from the memory address in r2 into r3.
<3> If the last comparison resulted in an 'eq' condition status, increments r4 by 4 then reads a word from the memory address in r4 into r5. Else, does nothing.
Privileged instruction:: No.
Updates program state flags:: No.
Exceptions::
MemFault.
<<<
[id=LDRIOW]
====== LDRIOW: Load Register+Immediate Post-indexed with Write-back
Description::
Reads a word from memory into the destination register then increments the source register.
The immediate offset `off` is added to the source register `src` after reading from memory into the destination register `dst`.
Encoding:: B1-Type
Assembler syntax::
+
[source]
----
ldr<cond?> <dst>, [<src>, <off?>]!
----
+
Where:
[horizontal]
cond::: Optional condition.
dst::: Destination register.
src::: Source register.
off:::
Optional offset immediate.
Must be a multiple of 4 and in the range -4096..4092.
If omitted, then 4 is used.
Examples::
+
[source]
----
ldr r1, [r0]! <1>
ldr r3, [r2, 8]! <2>
ldr.eq r5, [r4]! <3>
----
<1> Reads a word from the memory address in r0 into r1 then increments r0 by 4.
<2> Reads a word from the memory address in r2 into r3 then increments r2 by 8.
<3> If the last comparison resulted in an 'eq' condition status, reads a word from the memory address in r4 into r5 then increments r4 by 4. Else, does nothing.
Privileged instruction:: No.
Updates program state flags:: No.
@ -216,7 +73,7 @@ Exceptions::
<<<
[id=LDRR]
====== LDRR: Load Register+Register Pre-indexed
====== LDRR: Load Register+Register
Description::
Loads a word from memory into a register.
The value in the register `off` is added to the address in the `src` register before reading memory.
@ -225,12 +82,11 @@ Assembler syntax::
+
[source]
----
ldr<cond?> <dst>, [<src>, <off>]
ldr <dst>, [<src>, <off>]
----
+
Where:
[horizontal]
cond::: Optional condition.
dst::: Destination register.
src::: Source register.
off::: Offset register.
@ -240,82 +96,8 @@ Examples::
[source]
----
ldr r1, [sp, r0] <1>
ldr.eq r0, [r1, r2] <2>
----
<1> Reads a word from the memory address in sp into r1, adding the value of r0 as an offset.
<2> If the last comparison resulted in an 'eq' condition status, reads a word from the memory address in r1 into r0, adding the value of r2 as an offset. Else, does nothing.
Privileged instruction:: No.
Updates program state flags:: No.
Exceptions::
MemFault.
<<<
[id=LDRRW]
====== LDRRW: Load Register+Register Pre-indexed with Write-back
Description::
Increments the source register then reads a word from memory into the destination register.
The value in the register `off` is added to the `src` register value before reading a word from memory into the `dst` register.
Encoding:: A1-Type
Assembler syntax::
+
[source]
----
ldr<cond?> <dst>, ![<src>, <off>]
----
+
Where:
[horizontal]
cond::: Optional condition.
dst::: Destination register.
src::: Source register.
off::: Offset register.
Examples::
+
[source]
----
ldr r1, ![sp, r0] <1>
ldr.eq r0, ![r1, r2] <2>
----
<1> Adds the value of r0 into sp then reads a word from the memory address in sp into r1.
<2> If the last comparison resulted in an 'eq' condition status, adds the value of r2 into r1 then reads a word from the memory address in r1 into r0. Else, does nothing.
Privileged instruction:: No.
Updates program state flags:: No.
Exceptions::
MemFault.
<<<
[id=LDROW]
====== LDROW: Load Register+Register Post-indexed with Write-back
Description::
Reads a word from memory into the destination register then increments the source register.
The value in the register `off` is added to the source register `src` after reading from memory into the destination register `dst`.
Encoding:: A1-Type
Assembler syntax::
+
[source]
----
ldr<cond?> <dst>, [<src>, <off>]!
----
+
Where:
[horizontal]
cond::: Optional condition.
dst::: Destination register.
src::: Source register.
off::: Offset register.
Examples::
+
[source]
----
ldr r1, [sp, r0]! <1>
ldr.eq r0, [r1, r2]! <2>
----
<1> Reads a word from the memory address in sp into r1 then adds the value of r0 into sp.
<2> If the last comparison resulted in an 'eq' condition status, reads a word from the memory address in r1 into r0 then adds the value of r2 into r1. Else, does nothing.
<1> Reads a word from the memory address in sp into r1, using the value of r0 as an offset.
Privileged instruction:: No.
Updates program state flags:: No.

106
src/execution-engine-spec/instructions/ldrc.adoc Normal file
View File

@ -0,0 +1,106 @@
===== LDRC: Load Register Character
[wavedrom, ,svg]
....
{reg: [
{bits: 7, name: 0x3, type: 8, attr: '0x03'},
{bits: 4, name: 'off[3:0]', type: 5},
{bits: 5, name: 'dst', type: 2},
{bits: 5, name: 'src', type: 4},
{bits: 11, name: 'off[14:4]', type: 5}
], config: {label: {right: 'LDRCI'}}}
....
[wavedrom, ,svg]
....
{reg: [
{bits: 7, name: 0x6, type: 8, attr: '0x06'},
{bits: 4, name: 'unused'},
{bits: 5, name: 'dst', type: 2},
{bits: 5, name: 'src', type: 4},
{bits: 5, name: 'off', type: 4},
{bits: 6, name: 'unused'}
], config: {label: {right: 'LDRCR'}}}
....
[frame=ends,grid=rows,cols="1,1"]
|===
|Instruction variant | Description
|LDRCI
|<<LDRCI>>
|LDRCR
|<<LDRCR>>
|===
<<<
[id=LDRCI]
====== LDRCI: Load Character Register+Immediate
Description::
Loads a character (or byte) from memory into a register.
The immediate offset `off` is added to the address in the `src` register before reading memory.
Encoding:: B1-Type
Assembler syntax::
+
[source]
----
ldrc <dst>, [<src>, <off?>]
----
+
Where:
[horizontal]
dst::: Destination register.
src::: Source register.
off:::
Optional offset immediate.
Must be in the range -16384..16383.
If omitted, then 0 is used.
Examples::
+
[source]
----
ldrc r1, [r0] <1>
ldrc r3, [r2, 8] <2>
----
<1> Reads a character from the memory address in r0 into r1.
<2> Reads a character from the memory address in r2, with an 8 bytes offset, into r3.
Privileged instruction:: No.
Updates program state flags:: No.
Exceptions::
MemFault.
<<<
[id=LDRCR]
====== LDRCR: Load Character Register+Register
Description::
Loads a character (or byte) from memory into a register.
The value in the register `off` is added to the address in the `src` register before reading memory.
Encoding:: A1-Type
Assembler syntax::
+
[source]
----
ldrc <dst>, [<src>, <off>]
----
+
Where:
[horizontal]
dst::: Destination register.
src::: Source register.
off::: Offset register.
Examples::
+
[source]
----
ldrc r1, [sp, r0] <1>
----
<1> Reads a character from the memory address in sp into r1, using the value of r0 as an offset.
Privileged instruction:: No.
Updates program state flags:: No.
Exceptions::
MemFault.

106
src/execution-engine-spec/instructions/ldrh.adoc Normal file
View File

@ -0,0 +1,106 @@
===== LDRH: Load Register Halfword
[wavedrom, ,svg]
....
{reg: [
{bits: 7, name: 0x2, type: 8, attr: '0x02'},
{bits: 4, name: 'off[3:0]', type: 5},
{bits: 5, name: 'dst', type: 2},
{bits: 5, name: 'src', type: 4},
{bits: 11, name: 'off[14:4]', type: 5}
], config: {label: {right: 'LDRHI'}}}
....
[wavedrom, ,svg]
....
{reg: [
{bits: 7, name: 0x5, type: 8, attr: '0x05'},
{bits: 4, name: 'unused'},
{bits: 5, name: 'dst', type: 2},
{bits: 5, name: 'src', type: 4},
{bits: 5, name: 'off', type: 4},
{bits: 6, name: 'unused'}
], config: {label: {right: 'LDRHR'}}}
....
[frame=ends,grid=rows,cols="1,1"]
|===
|Instruction variant | Description
|LDRHI
|<<LDRHI>>
|LDRHR
|<<LDRHR>>
|===
<<<
[id=LDRHI]
====== LDRHI: Load Halfword Register+Immediate
Description::
Loads a halfword from memory into a register.
The immediate offset `off` is added to the address in the `src` register before reading memory.
Encoding:: B1-Type
Assembler syntax::
+
[source]
----
ldrh <dst>, [<src>, <off?>]
----
+
Where:
[horizontal]
dst::: Destination register.
src::: Source register.
off:::
Optional offset immediate.
Must be a multiple of 2 and in the range -32768..32766.
If omitted, then 0 is used.
Examples::
+
[source]
----
ldrh r1, [r0] <1>
ldrh r3, [r2, 8] <2>
----
<1> Reads a halfword from the memory address in r0 into r1.
<2> Reads a halfword from the memory address in r2, with an 8 bytes offset, into r3.
Privileged instruction:: No.
Updates program state flags:: No.
Exceptions::
MemFault.
<<<
[id=LDRHR]
====== LDRHR: Load Halfword Register+Register
Description::
Loads a halfword from memory into a register.
The value in the register `off` is added to the address in the `src` register before reading memory.
Encoding:: A1-Type
Assembler syntax::
+
[source]
----
ldrh <dst>, [<src>, <off>]
----
+
Where:
[horizontal]
dst::: Destination register.
src::: Source register.
off::: Offset register.
Examples::
+
[source]
----
ldrh r1, [sp, r0] <1>
----
<1> Reads a halfword from the memory address in sp into r1, using the value of r0 as an offset.
Privileged instruction:: No.
Updates program state flags:: No.
Exceptions::
MemFault.

16
src/execution-engine-spec/instructions/mov.adoc
View File

@ -3,7 +3,7 @@
....
{reg: [
{bits: 7, name: 0xd, type: 8, attr: '0x0d'},
{bits: 4, name: 'cond', type: 6},
{bits: 4, name: 'unused'},
{bits: 5, name: 'dst', type: 2},
{bits: 5, name: 'src', type: 4},
{bits: 11, name: 'unused'}
@ -14,9 +14,9 @@
....
{reg: [
{bits: 7, name: 0xe, type: 8, attr: '0x0e'},
{bits: 4, name: 'cond', type: 6},
{bits: 4, name: 'val[3:0]', type: 5},
{bits: 5, name: 'dst', type: 2},
{bits: 16, name: 'val', type: 5}
{bits: 16, name: 'val[19:4]', type: 5}
], config: {label: {right: 'MOVI'}}}
....
@ -41,12 +41,11 @@ Assembler syntax::
+
[source]
----
mov<cond?> <dst>, <src>
mov <dst>, <src>
----
+
Where:
[horizontal]
cond::: Optional condition.
dst::: Destination register.
src::: Source register.
@ -55,10 +54,8 @@ Examples::
[source]
----
mov r1, r0 <1>
mov.lt r3, lr <2>
----
<1> Copies the value from r0 into r1.
<2> If the last comparison resulted in an 'lt' condition status, copies the value from lr into r3. Else, does nothing.
Privileged instruction:: No.
Updates program state flags:: No.
@ -76,12 +73,11 @@ Assembler syntax::
+
[source]
----
mov<cond?> <dst>, <val>
mov <dst>, <val>
----
+
Where:
[horizontal]
cond::: Optional condition.
dst::: Destination register.
val::: Immediate value.
@ -90,10 +86,8 @@ Examples::
[source]
----
mov r0, 42 <1>
mov.eq r1, 1337 <2>
----
<1> Sets r0 to 42.
<2> If the last comparison resulted in an 'eq' condition status, sets r1 to 1337. Else, does nothing.
Privileged instruction:: No.
Updates program state flags:: No.

15
src/execution-engine-spec/instructions/movn.adoc
View File

@ -4,33 +4,32 @@
....
{reg: [
{bits: 7, name: 0x13, type: 8, attr: '0x13'},
{bits: 4, name: 'cond', type: 6},
{bits: 4, name: 'val[3:0]', type: 5},
{bits: 5, name: 'dst', type: 2},
{bits: 16, name: 'val', type: 5}
{bits: 16, name: 'val[19:4]', type: 5}
], config: {label: {right: 'MOVNI'}}}
....
Description::
Sets a destination register to the implied negative value given in the immediate field. +
The immediate value encoded in the instruction is a 16-bits absolute value.
The sign bit is implied to be set, making it a 17-bits signed integer with the last bit always set.
The immediate value encoded in the instruction is a 20-bits absolute value.
The sign bit is implied to be set, making it a 21-bits signed integer with the last bit always set.
The value is sign extended to fit in the 32-bits destination register.
Encoding:: C-Type
Assembler syntax::
+
[source]
----
movn<cond?> <dst>, <val>
movn <dst>, <val>
----
+
Where:
[horizontal]
cond::: Optional condition.
dst::: Destination register.
val:::
Immediate value.
The minus sign can be omitted as the value is always negative.
The value must be in the range -65636..-1.
The value must be in the range -1048576..-1.
Examples::
+
@ -38,11 +37,9 @@ Examples::
----
movn r0, -42 <1>
movn r0, 0x10 <2>
movn.eq r1, -1337 <3>
----
<1> Sets r0 to -42.
<2> Sets r0 to -0x10. The minus sign is omitted but the immediate value is still treated as being negative.
<3> If the last comparison resulted in an 'eq' condition status, sets r1 to -1337. Else, does nothing.
Privileged instruction:: No.
Updates program state flags:: No.