Download Intro to SPIM - ECE Users Pages

Intro to SPIM
Justin Fiore
Nathan Parish
Installing SPIM on Windows
• Download pcspim.zip from the SPIM
website:
http://www.cs.wisc.edu/~larus/SPIM/pcspi
m.zip
– It is also linked to on Dr. Lee’s page for this
class
• Unzip it
• Run Setup.exe
Installing SPIM on Linux from
Source
• Download
http://www.cs.wisc.edu/~larus/SPIM/spim.tar.gz
• Unzip it: tar xvzf spim.tar.gz
• cd spim-7.3/spim
• make
• cd ../xspim
• kmkmf
• make
Installing SPIM on Ubuntu Linux
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Open the Synaptic Package Manager
Click Settings->Repositories
Select one of the Binary repositories and click Edit
Check Non-free (Multiverse), and click OK
Click Close
Click Reload
Search for “spim”
Select the spim program and install it (this will install
xspim also)
• NOTE: This was done on Ubuntu Linux 6.06 LTS
(Dapper Drake)
Text Segment
• Your instructions are displayed here
• From left to right:
– Address where the instruction is stored
– Binary machine code for the instruction
– Assembly instruction (with registers represented as
numbers)
– Line number in your assembly source
– Assembly instruction from your source (with registers
as $s0, $v0, etc)
• Pseudo Instructions will be converted to one or
more assembly instructions
Message Segment
• Prints messages from SPIM such as:
– Loading the exception handler
– Loading your assembly file
– Any errors that SPIM encounters
Register Segment
• Displays the register contents
• Displays PC, Stack Pointer, Frame
Pointer, etc.
• Very important when debugging your code
Data Segment
• Displays the Data segment of memory.
– Heap (starts at “Data”)
– Stack (starts at “Stack”)
• Addresses are Byte Addressed
• Data is stored in words
• Data is represented in hexidecimal
Data Segment Example
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[0x10010000]
[0x10010010]
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0x10010000 = 0x65704f0a
0x10010004 = 0x69746172
0x10010008 = 0x20736e6f
0x1001000c = 0x70707553
0x10010010 = 0x6574726f
0x10010014 = 0x6e612064
0x10010018 = 0x79532064
0x1001001c = 0x7861746e
0x65704f0a 0x69746172 0x20736e6f 0x70707553
0x6574726f 0x6e612064 0x79532064 0x7861746e
Console
Debugging
• Click the “Hand” button to
add a breakpoint
• Add the instruction
address to break on
• After breaking, can
– single step (F10)
– multiple step (F11)
– Set Value (Simulator->Set
Value)
– Continue Executing (F5)
Input/Output in SPIM
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Place proper arguments (e.g. system call code) to corresponding registers
and place a ‘syscall’
•
Print string
» li $v0, 4
» la $a0, var
» syscall
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Print integer
» li $v0, 1
» add $a0, $t0, $0
» syscall
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Read integer
» li $v0, 5
» syscall
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See Appendix A for more.
# result in $v0