Merge pull request #1013 from rosethompson/main

Restored fpga file I should not have deleted

fpga/README.md

@@ -1,46 +1,57 @@
-The FPGA currently only targets the VCU118 board.
+Wally supports the following boards
 
-* Build Process
+1. ArtyA7
+2. vcu108
+3. vcu118 (Do not recommend.)
 
-cd generator
+# Quick Start
-make 
 
-* Description
+## build FPGA
 
-The generator makefile creates 4 IP blocks; proc_sys_reset, ddr4,
+`cd generator
-axi_clock_converter, and ahblite_axi_bridge.  Then it reads in the 4 IP blocks
+make <board name>`
-and builds wally.  fpga/src/fpgaTop.v is the top level which instanciates
-wallypipelinedsoc.sv and the 4 IP blocks.  The FPGA include and ILA (In logic
-analyzer) which provides the current instruction PCM, instrM, etc along with
-a large number of debuging signals.
 
-* Programming the flash card
+example
-You'll need to write the linux image to the flash card.  Use the convert2bin.py 
+`make vcu108`
-script in linux-testgen/linux-testvectors/ [*** moved?] to convert the ram.txt 
-file from QEMU's preload to generate the binary.  Then to copy
- sudo dd if=ram.bin of=<path to flash card>.
 
-* Loading the FPGA
+## Make flash card image
+ls /dev/sd* or ls /dev/mmc* to see which flash card devices you have.
+Insert the flash card into the reader and ls /dev/sd* or /dev/mmc* again.  The new device is the one you want to use.  Make sure you select the root device (i.e. /dev/sdb) not the partition (i.e. /dev/sdb1).
 
-After the build process is complete about 2 hrs on an i9-7900x. Launch vivado's
+`cd $WALLY/linux/sd-card`
-gui and open the WallyFPGA.xpr project file.  Open the hardware manager under
-program and debug. Open target and then program with the bit file.
 
-* Test Run
+This following script requires root.
 
-Once the FPGA is programed the 3 MSB LEDs in the upper right corner provide
+`./flash-sd.sh -b <path to buildroot> -d <path to compiled device tree file> <flash card device>`
-status of the reset and ddr4 calibration.  LED 7 should always be lit.
-LED 6 will light if the DDR4 is not calibrated.  LED 6 will be lit once
-wally begins running.
 
-Next the bootloader program will copy the flash card into the DDR4 memory.
+example with vcu108, buildroot installed to /opt/riscv/buildroot, and the flash card is device /dev/sdc
-When this done the lower 5 LEDs will blink 5 times and then try to boot
-the program loaded in the DDR4 memory at physical address 0x8000_0000.
 
-* Connecting uart
+`./flash-sd.sh -b /opt/riscv/buildroot -d /opt/riscv/buildroot/output/images/wally-vcu108.dtb /dev/sdc`
-You'll need to connect both usb cables.  The first connects the FPGA programer
-while the connect connects UART.  UART is configured to use 57600 baud with 
-no parity, 8 data bits, and 1 stop bit.  sudo screen /dev/ttyUSB1 57600 should
-let you view the com port.
 
+Wait until the the script completes then remove the car.
+
+## FPGA setup
+
+For the Arty A7 insert the PMOD daughter board into the right most slot and insert the sd card.
+
+For the VCU108 and VCU118 boards insert the PMOD daughter board into the only PMOD slot on the right side of the boards.
+
+Power on the boards. Arty A7 just plug in the USB connector. For the VCU boards make sure the power supply is connected and the two usb cables are connected. Flip on the switch.
+The VCU118's on board UART converter does not work. Use a spark fun FTDI usb to UART adapter and plug into the mail PMOD on the right side of the board.  Also the level sifters on the
+VCU118 do not work correctly with the digilent sd PMOD board.  We have a custom board which works instead.
+
+`cd $WALLY/fpga/generator
+vivado &`
+
+open the design in the current directory WallyFPGA.xpr.
+
+Then click "Open Target" under "PROGRAM AND DEBUG".  Then Program the device.
+
+## Connect to UART
+
+In another terminal ls /dev/ttyUSB*. One of these devices will be the UART connected to Wally. You may have to experiment by the running the following command multiple times.
+
+`screen /dev/ttyUSB1 115200`
+
+Swap out the USB1 for USB0 or USB1 as needed.
 

fpga/zsbl/bios.S

@@ -0,0 +1,102 @@
+#include "system.h"
+
+PERIOD = (SYSTEMCLOCK / 2)
+
+.section .init
+.global _start
+.type _start, @function
+
+		
+_start:
+	  # Initialize global pointer
+	.option push
+	.option norelax
+	1:auipc gp, %pcrel_hi(__global_pointer$)
+	addi  gp, gp, %pcrel_lo(1b)
+	.option pop
+	
+	li x1, 0
+	li x2, 0
+	li x4, 0
+	li x5, 0
+	li x6, 0
+	li x7, 0
+	li x8, 0
+	li x9, 0
+	li x10, 0
+	li x11, 0
+	li x12, 0
+	li x13, 0
+	li x14, 0
+	li x15, 0
+	li x16, 0
+	li x17, 0
+	li x18, 0
+	li x19, 0
+	li x20, 0
+	li x21, 0
+	li x22, 0
+	li x23, 0
+	li x24, 0
+	li x25, 0
+	li x26, 0
+	li x27, 0
+	li x28, 0
+	li x29, 0
+	li x30, 0
+	li x31, 0
+
+
+	# set the stack pointer to the top of memory - 8 bytes (pointer size)
+	li sp, (EXT_MEM_END - 8)
+
+	li a0, 0x00000000
+	li a1, EXT_MEM_BASE
+	#li a2, 128*1024*1024/512 # copy 128MB
+	li a2, 127*1024*1024/512 # copy 127MB upper 1MB contains the return address (ra)
+	#li a2, 800 # copy 400KB
+	jal ra, copyFlash
+	
+	fence.i
+	# now toggle led so we know the copy completed.
+
+	# write to gpio
+	li	t2, 0xFF
+	la	t3, 0x1006000C
+	li	t4, 5
+
+loop:
+
+	# delay
+	li	t0, PERIOD/2
+delay1:	
+	addi	t0, t0, -1
+	bge	t0, x0, delay1
+	sw	t2, 0x0(t3)
+
+	li	t0, PERIOD/2
+delay2:	
+	addi	t0, t0, -1
+	bge	t0, x0, delay2
+	sw	x0, 0x0(t3)
+
+	addi	t4, t4, -1
+	bgt	t4, x0, loop
+
+
+	# now that the card is copied and the led toggled we
+	# jump to the copied contents of the sd card.
+
+jumpToLinux:	
+	csrrs	a0, 0xF14, x0   # copy hart ID to a0
+	li	a1, FDT_ADDRESS  # This is the device tree address
+	la	a2, end_of_bios
+	li	t0, EXT_MEM_BASE  # start of code
+	
+	jalr	x0, t0, 0
+
+end_of_bios:	
+
+	
+
+