Help to run Hello Example

I'm new in community, i'd like some help!

I'm trying to run the Hello example from "" in my Nexys Video FPGA using the bitstream of Pulpissimo.

Until now i'm just following the instructions from file from "".

I had download and install the Toolchain from pulp-riscv-gnu-toolchain as "Newlib", could someone confirm that it is not necessary install the "Linux" version of this toolchain?

Then i installed the Standard Pulp SDK from ""

I had some issues following the steps, most of them are related with missing steps, like configuring bashrc or some ambient variable, but i was able to solve all of them i believe. I miss some kind of step-by-step, from rtl to running example on FPGA, is it possible create something like that? I think it could be done as a new Thread in forum for the communty, it could help a lot.

I was able to generate the bitstream of Pulpissimo and configure it in Nexys Video FPGA using the JTAG-USB connection. When i run the specific OpenOCD from Pulp-SDK, the OpenOCD is able to identify the Pulpissimo processor in FPGA.

Then i compiled the Hello Example after adding the two weakly defined variables as suggested to configure core and peripherics frequencies. It was compiled with success, the ELF file was properly generate in the build directory.

My problem happen when i had try to use GDB with ELF file to load it to L2 memory of Pulpissimo, the connection between the GDB and OpenOCD looks fine, when i use the Load command it copy the elf file to memory it looks to work fine too, but when i use the Continue command it stops and never end the execution, but it print some kind of assembly commands like;
# j    1c0080ec <__rt_illegal_instr>

So i did the check with gcc in the ELF file to check the Assembly, as suspected it was printing the assembly that has some kind of error i believe, the first piece of assembly code is like that;

test:     file format elf32-littleriscv

Disassembly of section .vectors:

1c008000 <__irq_vector_base>:
1c008000:    0ec0006f              j    1c0080ec <__rt_illegal_instr>
1c008004:    0900006f              j    1c008094 <__rt_no_irq_handler>
1c008008:    08c0006f              j    1c008094 <__rt_no_irq_handler>
1c00800c:    0880006f              j    1c008094 <__rt_no_irq_handler>
1c008010:    0840006f              j    1c008094 <__rt_no_irq_handler>
1c008014:    0800006f              j    1c008094 <__rt_no_irq_handler>
1c008018:    07c0006f              j    1c008094 <__rt_no_irq_handler>
1c00801c:    0780006f              j    1c008094 <__rt_no_irq_handler>
1c008020:    0740006f              j    1c008094 <__rt_no_irq_handler>
1c008024:    0700006f              j    1c008094 <__rt_no_irq_handler>
1c008028:    06c0006f              j    1c008094 <__rt_no_irq_handler>
1c00802c:    0680006f              j    1c008094 <__rt_no_irq_handler>
1c008030:    0640006f              j    1c008094 <__rt_no_irq_handler>
1c008034:    0600006f              j    1c008094 <__rt_no_irq_handler>
1c008038:    05c0006f              j    1c008094 <__rt_no_irq_handler>
1c00803c:    0580006f              j    1c008094 <__rt_no_irq_handler>
1c008040:    0540006f              j    1c008094 <__rt_no_irq_handler>
1c008044:    0500006f              j    1c008094 <__rt_no_irq_handler>
1c008048:    04c0006f              j    1c008094 <__rt_no_irq_handler>
1c00804c:    0480006f              j    1c008094 <__rt_no_irq_handler>
1c008050:    0440006f              j    1c008094 <__rt_no_irq_handler>
1c008054:    0400006f              j    1c008094 <__rt_no_irq_handler>
1c008058:    03c0006f              j    1c008094 <__rt_no_irq_handler>
1c00805c:    0380006f              j    1c008094 <__rt_no_irq_handler>
1c008060:    0340006f              j    1c008094 <__rt_no_irq_handler>
1c008064:    0300006f              j    1c008094 <__rt_no_irq_handler>
1c008068:    02c0006f              j    1c008094 <__rt_no_irq_handler>
1c00806c:    0280006f              j    1c008094 <__rt_no_irq_handler>
1c008070:    0240006f              j    1c008094 <__rt_no_irq_handler>
1c008074:    0200006f              j    1c008094 <__rt_no_irq_handler>
1c008078:    01c0006f              j    1c008094 <__rt_no_irq_handler>
1c00807c:    0180006f              j    1c008094 <__rt_no_irq_handler>

1c008080 <_start>:
1c008080:    0200006f              j    1c0080a0 <_entry>
1c008084:    0680006f              j    1c0080ec <__rt_illegal_instr>

1c008090 <__rt_debug_struct_ptr>:
1c008090:    0cf4                    addi    a3,sp,604
1c008092:    1c00                    addi    s0,sp,560

1c008094 <__rt_no_irq_handler>:
1c008094:    0000006f              j    1c008094 <__rt_no_irq_handler>

1c008098 <__rt_semihosting_call>:
1c008098:    00100073              ebreak
1c00809c:    00008067              ret

Disassembly of section .text:

1c0080a0 <_entry>:
1c0080a0:    7a101073              csrw    pcmr,zero
1c0080a4:    ffff9297              auipc    t0,0xffff9
1c0080a8:    d2c28293              addi    t0,t0,-724 # 1c000dd0 <_bss_start>
1c0080ac:    ffff9317              auipc    t1,0xffff9
1c0080b0:    e0030313              addi    t1,t1,-512 # 1c000eac <__l2_priv0_end>
1c0080b4:    0002a023              sw    zero,0(t0)
1c0080b8:    0291                    addi    t0,t0,4
1c0080ba:    fe62ede3              bltu    t0,t1,1c0080b4 <_entry+0x14>
1c0080be:    ffff9117              auipc    sp,0xffff9
1c0080c2:    c0210113              addi    sp,sp,-1022 # 1c000cc0 <stack>
1c0080c6:    292000ef              jal    ra,1c008358 <__rt_init>
1c0080ca:    00000513              li    a0,0
1c0080ce:    00000593              li    a1,0
1c0080d2:    00000397              auipc    t2,0x0
1c0080d6:    26438393              addi    t2,t2,612 # 1c008336 <main>
1c0080da:    000380e7              jalr    t2
1c0080de:    842a                    mv    s0,a0
1c0080e0:    350000ef              jal    ra,1c008430 <__rt_deinit>
1c0080e4:    8522                    mv    a0,s0
1c0080e6:    330010ef              jal    ra,1c009416 <exit>

1c0080ea <_fini>:
1c0080ea:    8082                    ret

1c0080ec <__rt_illegal_instr>:
1c0080ec:    fe112e23              sw    ra,-4(sp)
1c0080f0:    fea12c23              sw    a0,-8(sp)
1c0080f4:    00000517              auipc    a0,0x0
1c0080f8:    3ba50513              addi    a0,a0,954 # 1c0084ae <__rt_handle_illegal_instr>
1c0080fc:    010000ef              jal    ra,1c00810c <__rt_call_c_function>
1c008100:    ffc12083              lw    ra,-4(sp)
1c008104:    ff812503              lw    a0,-8(sp)
1c008108:    30200073              mret

1c00810c <__rt_call_c_function>:
1c00810c:    7119                    addi    sp,sp,-128
1c00810e:    c006                    sw    ra,0(sp)
1c008110:    c20e                    sw    gp,4(sp)
1c008112:    c412                    sw    tp,8(sp)
1c008114:    c616                    sw    t0,12(sp)

What could i have done to generate some kind of illegal instruction during the compiling process? is it not wrong after all?

When i use the gdb command "disas" it print the C code properly...

If you need any more information, just ask

Any help will be very helpful

Best Regards, Igor Ruschi

Messages In This Thread
Help to run Hello Example - by igor.lima - 12-01-2020, 08:05 PM
RE: Help to run Hello Example - by LPLA - 12-02-2020, 10:46 AM
RE: Help to run Hello Example - by zealshah29 - 03-28-2024, 06:31 AM
RE: Help to run Hello Example - by meggiman - 12-02-2020, 06:19 PM
RE: Help to run Hello Example - by igor.lima - 01-11-2021, 08:00 PM
RE: Help to run Hello Example - by igor.lima - 01-12-2021, 07:00 PM

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