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From: Jeremy Bennett<jeremy.bennett@e...>
Date: Mon Sep 22 09:46:26 CEST 2008
Subject: [openrisc] problem with running "hello uart" in v2pro

On Sun, 2008-09-21 at 21:52 -0700, wuxian wrote: > Hello,everybady. > I'm new here. > For the last few weeks I try to run the "hello uart" program in v2pro. I > built a program using the openrisc-HW-tutorial-Xilinx and > openrisc-SW-tutorial. > Then I tryed to run the program > download the .bit file > run jtag > -cd ... //location of jtag > -./jp1 xpc3 9999 > > run gdb > -cd ... //location of hello-uart > -or32-uclinux-gdb hello.or32 > -target jtag jtag://localhost:9999 > -load > -set $pc=0x100 > -run > And there came the problem, the openrisc CPU didn't send control signal to > URAT union. > In the hello.or32 file, I found the reset.S instruction in 2100h and the > uart_init instruction in 4000h. > By using the JTAG ,I get the instruction which I have just download from the > ram. But I couldn't find the reset.S instruction which supposed to begin at > 0x100 any where.And the uart_init instruction which is supposed to begin > after address 0x100 is founded in 0x00. > So I restart the system,set the PC 0x00,run the program. And it doesn't work > either. > Is there anyone met this problem before.Do you think there is something > wrong with my tool chain? > Because the tutorial I use is too old , I had to do something different from > what it tells.I downloaded the gdb5.3.patch from the > http://www.eecg.utoronto.ca/~jarvin/or32/gdb-5.3.patch.bz2. Hi Wuxian, These tutorials are very out of date, particularly the software one. I don't have physical Virtex-II hardware here, so I can't check that end. Are you using a Xilinx Parallel Cable 3? On the software side, I strongly recommend you change to GDB 6.8, as described on the OpenRISC software site. At a first glance, I'm not sure that you are using GDB correctly to load your program on the remote machine. Try instead: or32-uclinux-gdb file hello.or32 <---- You need a local symbol table target jtag jtag://localhost:9999 <---- Connect to the target load hello.or32 <---- This will load on the target x/i 0x100 <---- Has it loaded correctly set $pc=0x100 <---- Is this necessary? run GDB 6.8 should set $pc automatically to the entry point specified in the binary, which I would hope is 0x100. I have heard of a problem with the Igor Mohor debug unit, which will not allow the PC to be set via JTAG. Which Verilog source are you using? ORPSoC? (this has a different debug unit, not the Igor Mohor one). I would recommend that you recompile the software example, using the current version of the tool chain, and verify that it works using Or1ksim first. If you can get the program to run with Or1ksim, then the problem is somewhere in the interface between the hardware and the debugger. You should check that the expected sequence of commands are being sent across the OpenRISC Remote JTAG protocol. This is a very simple protocol with commands to read & write single JTAG registers, or blocks of JTAG registers and to change the JTAG scan chain being addressed. The debug unit has 3 scan chains of relevance, 1 to access the SPRs, one to access main memory, and one to control the CPU by stalling or resetting the processor. The functions which drive this in GDB (assuming GDB 6.8) are in the file gdb/or1k-jtag.c. You can either modify these functions to print out messages as each protocol command is sent, or you can run OpenRISC GDB under GDB. For example, start up GDB as above, and note its process ID (say 12345). Then debug it from a separate window using: gdb or32-uclinux-gdb 12345 break or1k_jtag_init break or1k_jtag_close break or1k_jtag_read_spr break or1k_jtag_write_spr break or1k_jtag_read_mem break or1k_jtag_write_mem break or1k_jtag_stall break or1k_jtag_unstall break or1k_jtag_wait cont Then issue the commands to OpenRISC GDB in its window as above. The local GDB will break as it encounters each of the JTAG protocol functions, and you can examine what is being requested, step through the code etc, to verify the JTAG commands being transmitted. You may find it useful to build OpenRISC GDB with debugging info in for this. Follow the usual instructions, but use make all CFLAGS+=-ggdb instead of "make all" You'll need to look at the code in gdb/or1k-jtag.c to understand what is happening for each of these functions. It is well commented, and there is a description in: http://www.embecosm.com/download/ean3.html If this is all working correctly, then the problem must be in the jp1 side. You'll need to debug this, and check that it is receiving the OpenRISC JTAG protocol commands properly and generating the correct JP1 interface commands. If this is not the source of the problem, then you have a problem in the hardware of the debug unit. You'll need to run under simulation to work out where that problem is. Hope you can get the system working. You can ensure your everlasting fame, by writing a new paper on how to use OpenRISC with a Virtex-II FPGA, which we could post on the website. HTH, Jeremy -- Tel: +44 (1202) 416955 Cell: +44 (7970) 676050 SkypeID: jeremybennett Email: jeremy.bennett@e... Web: www.embecosm.com

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[openrisc] problem with running "hello uart" in v2pro Wuxian