You do not want to simulate a mkprom image in VHDL, trust me.
Even the smallest image will execute ~ 1,000,000 instructions
before entering main() in RAM. This is only ~ 30 ms on real
hardware at 50 MHz, but ~ 10 hours in VHDL (on a fast host).

You can easily see in TSIM how many instructions you will need:

sparc-elf-gcc -msoft-float hello.c -o hello.exe -lsmall
sparc-elf-mkprom hello.exe -nocomp -nomsg

tsim-leon3 prom.out
.
.
section: .text, addr: 0x0, size 34304 bytes
read 103 symbols
tsim> bre 0x40000000
breakpoint 1 at 0x40000000: .bdata
tsim> run
breakpoint 1 .bdata
tsim> per

Cycles : 1399497
Instructions : 906783
Overall CPI : 1.54

CPU performance (50.0 MHz) : 32.40 MOPS (32.40 MIPS, 0.00 MFLOPS)
Cache hit rate : 98.7 % (100.0 / 80.0)
AHB bandwidth utilisation : 33.7 % ( 0.4 / 33.3)
Simulated time : 27.99 ms
Processor utilisation : 100.00 %
Real-time performance : 11.86 %
Simulator performance : 3843.69 KIPS
Used time (sys + user) : 0.24 s


So even if we created the smallest possible binary using -lsmall
and fastest mkprom loading with -nomsg and -nocomp, you will need
to execute 906,783 instructions to get to RAM, and then maybe an
other 10,000 to get to main(). This is why the test bench in leon3
designs does NOT use mkprom, but a simple assembly reset sequence
and a pre-loaded RAM image...

Jiri.


sacliv wrote:
> Hey guys, I'm trying to load a test c program i wrote on the leon3 in
> the vhdl leon3 code and run it in modelsim to view the waveforms.
>
> I followed the bcc manual and did mkprom on my executable, and then i
> copied the .srec file to the testbench directory, and in the
> testbench.vhd, i changed the filename of the prom.srec to test.srec,
> which is my srec file.
>
> The test program is very simple and just prints out hello world, but
> in the modelsim simulation of the leon3, i'm watching the pc and
> instructions of the leon3 core, but i can't seem to get to my test
> program.
>
> Does anyone know either how long i have to simulate it until before i
> get to main() in my test program? Or if i'm doing it wrong, what's the
> correct procedure? Thanks!
>
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> Yahoo! Groups Links
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