riscvp2 _clkset not working
n_ermosh
Posts: 294
Trying to get riscvp2 running from https://github.com/totalspectrum/riscvp2 and the loader from https://github.com/totalspectrum/loadp2. I'm able to compile and load programs, but it seems like _clkset() doesn't work. Below is my code and Makefile.
code:
Makefile:
The result printed is:
I also tried patching in the clock frequency and mode, and the I get the following error from the loader:
am I doing something wrong or is this a bug? Also should mention I tried including "-PATCH" option to the loader and no difference in result.
And tangentially related, is there a way to change the serial baudrate during runtime or does it have to be patched in via the loader?
code:
#include <propeller.h>
#include <sys/p2_clock.h> // must be inluded in top level for defining _SETFREQ and _CLOCKFREQ based on defined clock frequency in makefile
#include <stdio.h>
#include <stdint.h>
void main() {
_clkset(_SETFREQ, _CLOCKFREQ);
printf("clock set 0x%x, should be 0x%x\n", *(int*)0x18, _SETFREQ);
printf("clock frequency %u Hz, should be %d\n", _clkfreq, _CLOCKFREQ);
while(1);
}
Makefile:
TOOLCHAIN = /opt/riscvp2 CC = $(TOOLCHAIN)/bin/riscv-none-embed-gcc LOAD = $(TOOLCHAIN)/bin/loadp2 # hardware and project config PORT = /dev/cu.usbserial-* OBJDIR = build LOAD_MODE = load TARGET_FREQ = 200 # in MHz XTALFREQ = 20000000 # in Hz XOSC = 2 # CLKFREQ = 160000000 # CLKMODE = 010009f8 CFLAGS = -Wl,-Tfastmath.ld CLK_CFG = -DP2_TARGET_MHZ=$(TARGET_FREQ) -D_XTALFREQ=$(XTALFREQ) -D_XOSC=$(XOSC) LOADFLAGS = -t -b 230400 #-f $(CLKFREQ) -m $(CLKMODE) .PHONY: all setup load clean all: setup $(OBJDIR)/main.elf $(LOAD_MODE) setup: $(shell pkill loadp2) mkdir -p $(OBJDIR) $(OBJDIR)/main.elf: $(OBJDIR)/main.o $(CC) -T riscvp2.ld -o $@ $(CFLAGS) $^ $(OBJDIR)/main.o: main.c $(CC) -T riscvp2.ld -c $(INCLUDES) -o $@ $(CFLAGS) $(CLK_CFG) $< load: $(OBJDIR)/main.elf $(LOAD) $(LOADFLAGS) -p $(PORT) $< clean: rm -rf ./$(OBJDIR)/*
The result printed is:
clock set 0x10007f8, should be 0x10009f8 clock frequency 160000000 Hz, should be 200000000
I also tried patching in the clock frequency and mode, and the I get the following error from the loader:
/opt/riscvp2/bin/loadp2 -t -b 230400 -f 160000000 -m 010009f8 -p /dev/cu.usbserial-* build/main.elf ERROR: timeout waiting for initial checksum: got -1
am I doing something wrong or is this a bug? Also should mention I tried including "-PATCH" option to the loader and no difference in result.
And tangentially related, is there a way to change the serial baudrate during runtime or does it have to be patched in via the loader?
Comments
When _clkset() is called the serial baud rate is updated based on whatever value is in *(unsigned *)0x1c. So you could patch that manually before calling _clkset() in order to change the baud.
Thanks for the bug report,
Eric
On an unrelated note, is there a way to start native PASM cogs with risvp2? I have a PASM driver I want to load. In propgcc, there was a special way to compile these with the cog mode memory model, does riscvp2 have something similar?
Yes, there is. I used the micropython source to figure it out. https://github.com/totalspectrum/micropython/tree/totalspectrum/ports/riscv-p2
The process goes like this:
1. Write spin object.
2. Run spin2cpp. It will generate .c and .h files from the spin source. Spin2cpp records the actual command used at the top of the .c and .h files. PASM code is converted to a byte array.
3. Incorporate the spin2cpp output .c and .h files into the gcc project.
A simple PASM program:
DAT org 0 mov pin, ptra led_loop drvnot pin waitx wait jmp #led_loop wait long 100000000 pin long 0build it with fastspin to make a binary (led.bin), then compile a wrapper assembly program with the riscvp2 gcc:
.text .globl _cog_led_start _cog_led_start: .incbin "build/led.bin"and link it with the main program
#include <propeller.h> #include <stdio.h> #include <stdint.h> #define PIN 56 extern uint32_t _cog_led_start[]; void main() { _cognew(_cog_led_start, PIN); //printf("starting...\n"); while(1); }This seems to mirror how propgcc did it on P1.
What I am now having trouble with is starting a cog that's just another C function, i.e:
#include <propeller.h> #include <stdio.h> #include <stdint.h> #define PIN 56 #define PIN2 57 extern uint32_t _cog_led_start[]; void led_start() { _dirh(PIN2); _outh(PIN2); while(1); } void main() { _cognew(_cog_led_start, PIN); _cognew(led_start, 0); while(1); }But pin 57 does not go high. Does riscvp2 support starting other cogs that aren't native code (similar to starting other cmm cogs in propgcc)?
BTW there was a conflict between _clkset and the FPU code, which I've just pushed a fix for, so you may want to grab a newer copy.
Okay, so sounds like the only options for multiple cogs is to compile binaries with fastspin? and I'm assuming that it will need to fit into the 496 longs of cog memory?
Yeah was just testing the clkset fix and noticed it wasn't working, and then saw a new commit. Works now, thanks!
You do have to compile with fastspin (or PNut, or spin2cpp), but the code doesn't have to fit in cog memory. It's quite OK to do hubexec or to load code into LUT. The tricky part is finding the addresses of the code in hub memory. You'll either have to make everything position independent, or else use spin2cpp to convert some PASM to hex bytes; in that case spin2cpp also produces a relocation table for the PASM code and a constructor to perform the relocation.