System commands

This section describes the commands of MSIM. These commands can be used either in the interactive mode or in a configuration file.

`add`: Add a new device into the system 

Add a new device into the system under a specified name.

add device_type device_name [device_parameters...]

device_type: Specifies a device type. The list of available device types is in the Devices section.
device_name: An identifier of the newly created device. The name must not be equal to a system command and must be unique among already added devices.
device_parameters: Initial device parameters. The actual parameters depends on the device type.

Example

The first example adds a new printer p0 to the system. The printer register is located at physical address 0x0001000.

[msim] add dprinter p0 0x1000

The second example adds a read-only memory m0 mapped at physical address 0x00010000. The size of the memory is 16 KB.

[msim] add rom m0 0x10000 16k

`dumpmem`: Dump words from unmapped memory 

Print a part of a memory from an unmapped address.

dumpmem address count

address: Starting address of the memory block.
count: Number of words to print.

Example

The following example prints 10 words from the physical address 0x00001240.

[msim] dumpmem 0x1240 10
  00001240    265a45cd  2fefe111  11deadee  30957311
  00001250    7b218f9f  ffff2345  baba5555  deadbeaf
  00001260    29dc9aff  1298aa23
[msim]

`dumpins`: Dump instructions from unmapped memory 

Print disassembled instructions from the specified unmapped address.

dumpins cpu address count

cpu: CPU architecture instructions of which will be dumped. (r4k or rv)
address: Starting address of the memory block.
count: Number of instructions to print.

Example

The following example prints 10 MIPS R4000 instructions from the address 0x000012a8.

[msim] dumpins r4k 0x12a8 10
    000012A8    ori   s0, s0, 0x5427    # 0x5427h=21543
    000012AC    sw    s2, 0x18(sp)      # 0x18=24
    000012B0    lui   s2, 0x805a        # 0x805a=32858
    000012B4    ori   s2, s2, 0xce55
    000012B8    sw    s1, 0x14(sp)      # 0x14=20
    000012BC    lui   s1, 0x8100        # 0x8100=33024
    000012C0    sw    ra, 0x1c(sp)      # 0x1c=28
    000012C4    lw    a0, 0x1640(gp)    # 0x1640=5696
    000012C8    jal   +0x4009d4         # 0x4009d4=4196820
    000012CC    nop
[msim]

`dumpdev`: Dump all installed devices 

Print a list of devices with parameters configured in the environment.

Example

The following example prints all devices in the system.

[msim] dumpdev
[  name  ] [  type  ] [ parameters...
printer    dprinter   address:0x01000000
startmem   rom        start:0x1fc00000 size:1k type:mem
xxx        rwm        start:0x00400000 size:256k type:mem
mainmem    rwm        start:0x00000000 size:256k type:mem
mips1      dcpu       type:R4000.32
[msim]

`dumpphys`: Dump all installed memory blocks 

Print all configured memory blocks.

Example

The following example prints all installed memory blocks.

[msim] dumpphys
[  name  ] [  type  ] [ parameters...
startmem   rom        start:0x1fc00000 size:1k type:mem
xxx        rwm        start:0x00400000 size:256k type:mem
mainmem    rwm        start:0x00000000 size:256k type:mem
[msim]

`break`: Add memory breakpoint 

Add memory access breakpoint. If a read or write access on the the physical address of the breakpoint occurs, the simulator is immediately switched to interactive mode.

break address count type

address: Address of the breakpoint.
count: Size of the breakpoint (amount of bytes watched for the access).
type: Consider read accesses (r), write accesses (w) or both (rw).

`dumpbreak`: Dump memory breakpoints 

Print all configured memory access breakpoints.

`rembreak`: Remove memory breakpoint 

Remove previously configured memory breakpoint.

rembreak address

address: Address of the previously configured breakpoint.

`stat`: Dump available statistic information 

Print statistics of installed devices.

Example

The following example prints the statistics of all the installed devices.

[msim] stat
[  name  ] [  type  ] [ statistics...
printer    dprinter   count:42248
startmem   rom        no statistics
xxx        rwm        no statistics
mainmem    rwm        no statistics
mips1      dcpu       cycles total:1373061 in kernel:1373061 in user:0
                      in stdby:0 tlb refill:0 invalid: 0 modified:0
                      interrupts 0:0 1:0 2:0 3:0 4:0 5:0 6:0 7:0
[msim]

`echo`: Print user message 

Print user message. The echo command is usually used for debugging purposes, mainly in the configuration file.

echo message

message: String which will be printed.

Example

The following example prints the message “The point A has been reached”.

[msim] echo "The point A has been reached"
The point A has been reached
[msim]

`continue`: Continue simulation 

Continue in the simulation. The interactive mode is leaved.

Example

In the following example, the execution is terminated by pressing Ctrl+C and later restarted by the continue command. The trace mode in still on:

...

 0  80400ED4    subu  v0, v0, a1        # v0: 0x24640->0x245b7
 0  80400ED8    sll   v1, v0, 0x02      # v1: 0xb71d6a00->0x916dc
<Ctrl+C>
[msim] continue
 0  80400EDC    addu  v0, v0, v1        # v0: 0x245b7->0xb5c93
 0  80400EE0    sll   v0, v0, 0x04      # v0: 0xb5c93->0xb5c930
 0  80400EE4    addu  v0, v0, a1        # v0: 0xb5c930->0xb5c9b9

...

`step`: Simulate one or a specified number of instructions 

Execute one or a specified number of cycles. The step command is default (it is executed if a blank command line entered).

step [count]

count: Optional number of cycles to execute.

Example

In the following example, the user executes 3 steps on a 2-processor machine:

[msim] s 3
80400ACC    mfc0  v0, status        # v0: 0x0->0x8001
80400EC4    srl   a1, a1, 0x18      # 0x18=24, a1: 0x6538b04f->0x65
80400AD0    addiu v1, 0, 0xfffe     # v1: 0x0->0xfffffffe
80400EC8    sll   v0, a1, 0x04      # v0: 0x219dad69->0x650
80400AD4    and   v0, v0, v1        # v0: 0x8001->0x8000
80400ECC    addu  v0, v0, a1        # v0: 0x650->0x6b5
[msim]

`set`: Set environment variable 

Set an internal variable on or to a specified value or print a list of all variables.

set [variable [= value]]

variable: Name of the internal variable name to be set (if not specified, list of all variables is printed).
value: Value to be assigned to the variable (if not specified, logical true is assumed).

Refer to the Internal variables section for a list and a description of available variables. If value is not specified, the variable is set to the logical true. Note that not all variables can hold a logical values.

For boolean variables, there are several synonyms for true: true, on, yes. Similarly the synonyms for false are: false, off, no and their prefixes.

Example

In the first example, we list all the variables:

[msim] set
Group                  Variable   Value
---------------------- ---------- ----------
Disassembling features
                       iaddr      on
                       iopc       off
                       icmt       on
                       iregch     on
                       r4k_ireg   2
                       rv_ireg    1
Debugging features
                       trace      off
[msim]

In the second example, we switch to trace mode:

[msim] s
[msim] set trace
[msim] s
    0  80401378    addiu a0, a0, 0x40      # 0x40=64, a0: 0xb7b8->0xf8
[msim]

And in the third example, we set the type of register names:

[msim] set r4k_ireg = 2
[msim] id 0x00401330 1
    00401330    srl   v0, v0, 0x01
[msim] set r4k_ireg = 0
[msim] id 0x00401330 1
    00401330    srl   r2, r2, 0x01
[msim]

`unset`: Unset environment variable 

Unset a logical internal variable.

unset variable

variable: Internal variable name to be unset.

Specified variable must hold a logical value. Refer to the Internal variables section for the list and description of available variables.

Example

In the following example, the trace mode is switched off:

[msim] s
    0  80401334    addu  r5, r5, r2        # r5: 0x6512c4be->0x9754a5b8
[msim] unset trace
[msim] s
[msim]

`help`: Display a help text 

Show the help for the specified system command or print the list of available system commands.

help [command]

command: Command name (if omited, the list of available system commands is printed).