Initial Checkin

6 files changed, 295 insertions, 0 deletions

diff --git a/bootrom/bram.mk b/bootrom/bram.mk
new file mode 100644
index 0000000..2c7875a
--- /dev/null
+++ b/bootrom/bram.mk
@@ -0,0 +1,79 @@
+ifndef _BRAM_MK
+_BRAM_MK := # defined
+
+BRAM_ADDR := 0x1000
+
+BASEDIR := $(dir $(lastword $(MAKEFILE_LIST)))
+BASEDIR := $(BASEDIR:/=)
+DATADIR := $(BASEDIR)/common
+
+LDSCRIPT := $(DATADIR)/bram.ld
+MEMSCRIPT := $(DATADIR)/mem.awk
+
+BITFILEDIR := $(BASEDIR)/../bitfile
+BITFILE_VERSION ?= 0-1
+
+BITFILE := $(BITFILEDIR)/freedom-e300-arty-$(BITFILE_VERSION).bit
+CFGFILE := $(BITFILEDIR)/FreedomE-$(BITFILE_VERSION).cfg
+MEMINFO := $(BITFILEDIR)/freedom-e300-arty-$(BITFILE_VERSION).mmi
+BRAM_INST := `cat $(BITFILEDIR)/freedom-e300-arty-$(BITFILE_VERSION)-bootrom.txt`
+
+XLEN = 32
+BRAM_WIDTH=64
+
+all: mcs
+
+$(BITFILE):
+	@echo "In order to get Version $(BITFILE_VERSION) of the bitfile:"
+	@echo ""
+	@cat $(BITFILEDIR)/README.md
+
+CC := ../../toolchain/bin/riscv$(XLEN)-unknown-elf-gcc
+UPDATEMEM ?= updatemem
+
+CDEFINES += -DCFG_STRING=\"$(CFGFILE)\"
+
+CFLAGS ?= -m$(XLEN) -O2 -std=c11 -pedantic -Wall \
+	-nostartfiles -fno-common -mcmodel=medany -g \
+	$(CDEFINES)
+
+LDFLAGS ?= -T$(LDSCRIPT) -static -nostdlib
+OBJCOPY ?= objcopy
+elf: $(PROG).elf
+hex: $(PROG).hex
+mem: $(PROG).impl.mem
+mcs: $(PROG).mcs
+
+$(PROG).elf: $(SRCS) $(EXTRAS) $(CFGFILE)
+	$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $(SRCS)
+
+$(PROG).hex: $(PROG).elf
+	$(OBJCOPY) -S -O verilog --change-addresses -$(BRAM_ADDR) $< $@
+
+# Manually reverse the byte order due to limitations in UpdateMEM.
+# Per UG898: "When UpdateMEM inputs data, it takes data from data input
+# files in Bit Lane sized chunks from the most right value first to the
+# left most.  For example, if the first 64 bits of input data are
+# 0xB47DDE02826A8419 then the value 0xB4 is the first value to be set
+# into a Block RAM."
+$(PROG).impl.mem: $(PROG).hex $(MEMSCRIPT)
+	awk -v WIDTH=$(BRAM_WIDTH) -v REVERSE=1 -f $(MEMSCRIPT) $< > $@
+
+.PHONY: $(PROG).mcs
+$(PROG).mcs : $(BITFILE) $(PROG).impl.mem
+	@echo ""
+	@echo ""
+	@echo "TO COMPLETE THE BUILD OF $(PROG).mcs, "
+	@echo "ENTER THE FOLLOWING IN THE VIVADO TCL WINDOW:"
+	@echo ""
+	@echo "cd `pwd`"
+	@echo ""
+	@echo "exec $(UPDATEMEM) -meminfo $(MEMINFO) -data $(PROG).impl.mem -proc $(BRAM_INST) -bit $(BITFILE) --out $(PROG).bit -force"
+	@echo ""
+	@echo "write_cfgmem -format mcs -interface spix4 -size 16 -loadbit {up 0x0 $(PROG).bit} -file $(PROG).mcs -force"
+	@echo ""
+
+clean:
+	rm -f -- $(foreach ext,elf hex impl.mem bit mcs,$(PROG).$(ext))
+
+endif # _BRAM_MK
diff --git a/bootrom/common/bram.ld b/bootrom/common/bram.ld
new file mode 100644
index 0000000..45df67f
--- /dev/null
+++ b/bootrom/common/bram.ld
@@ -0,0 +1,40 @@
+OUTPUT_ARCH("riscv")
+ENTRY(_start)
+
+MEMORY
+{
+	rom (rx) : ORIGIN = 0x00001000, LENGTH = 4K
+	ram (rwx) : ORIGIN = 0x80000000, LENGTH = 256M
+}
+
+SECTIONS
+{
+	PROVIDE(_rom = ORIGIN(rom));
+	PROVIDE(_rom_end = _rom + LENGTH(rom));
+	PROVIDE(_ram = ORIGIN(ram));
+	PROVIDE(_ram_end = _ram + LENGTH(ram));
+
+	.text : {
+		PROVIDE(_ftext = .);
+		*(.text.init)
+		*(.text .text.* .gnu.linkonce.t.*)
+		PROVIDE(_etext = .);
+	} > rom
+
+	.rodata : {
+		*(.rodata .rodata.* .gnu.linkonce.r.*)
+	} > rom
+
+	.bss : ALIGN(8) {
+		PROVIDE(_fbss = .);
+		*(.bss .bss.* .gnu.linkonce.b.*)
+		*(.sbss .sbss.* .gnu.linkonce.sb.*)
+		. = ALIGN(8);
+		PROVIDE(_ebss = .);
+	} > ram
+
+	. += 0x1000;
+	PROVIDE(_sp = NEXT(0x1000));
+
+	PROVIDE(_end = .);
+}
diff --git a/bootrom/common/mem.awk b/bootrom/common/mem.awk
new file mode 100644
index 0000000..3003b56
--- /dev/null
+++ b/bootrom/common/mem.awk
@@ -0,0 +1,63 @@
+BEGIN {
+	RS = ORS = "\r\n"
+	addr = 0
+	buf = ""
+	limit = (WIDTH > 0 ? WIDTH / 4 : 16)
+	print "@00000000"
+}
+
+# Portable strtonum() replacement
+function atoi(str,	x, n, i, b, c) {
+	if (str ~ /^0[0-7]*$/) {
+		i = 2
+		b = 8
+	} else if (str ~ /^0[xX][[:xdigit:]]+$/) {
+		i = 3
+		b = 16
+	} else {
+		return str
+	}
+
+	x = 0
+	n = length(str)
+	for (; i <= n; i++) {
+		c = tolower(substr(str, i , 1))
+		c = index("123456789abcdef", c)
+		x = (x * b) + c
+	}
+	return x
+}
+
+function out(x) {
+	addr++
+	buf = (REVERSE ? buf x : x buf)
+	if (length(buf) >= limit) {
+		print buf
+		buf = ""
+	}
+}
+
+function pad(n) {
+	while (addr < n) {
+		out("00")
+	}
+}
+
+match($1, /^@[[:xdigit:]]+/) {
+	pad(atoi("0x" substr($1, RSTART+1, RLENGTH-1)))
+	next
+}
+
+{
+	for (i = 1; i <= NF; i++) {
+		out($i)
+	}
+}
+
+END {
+	align = limit / 2
+	pad(int((addr + align - 1) / align) * align)
+	if (length(buf) > 0) {
+		print buf;
+	}
+}
diff --git a/bootrom/demo/Makefile b/bootrom/demo/Makefile
new file mode 100644
index 0000000..dfe3663
--- /dev/null
+++ b/bootrom/demo/Makefile
@@ -0,0 +1,5 @@
+PROG := demo
+SRCS := demo.S
+EXTRAS := hello_msg.txt
+
+include ../bram.mk
diff --git a/bootrom/demo/demo.S b/bootrom/demo/demo.S
new file mode 100644
index 0000000..c6f2618
--- /dev/null
+++ b/bootrom/demo/demo.S
@@ -0,0 +1,71 @@
+#define UART_BASE	0x48000000
+#define SPI_BASE	0x48001000
+#define GPIO_BASE	0x48002000
+
+#ifndef CFG_STRING
+#error Must define CFG_STRING
+#endif	
+        
+	.globl _start
+_start:
+	j uart_init
+	nop
+	nop
+	.word cfgstr
+
+uart_init:
+        // a1 = UART_TX
+        // a2 = hello_msg_end
+        // for (a0 = hello_msg_start; a0 != a2; ++ a0){
+        //   while (a3 = TX_READY == 0);
+        //   a3 = *a0
+        //   *a1 = a3
+        // }
+
+        la a0, hello_msg_start
+        la a2, hello_msg_end
+        li a1, UART_BASE
+                
+uart_loop:      
+        lw a3, 4(a1) // Wait until non-zero (uart can send data).
+        beqz a3, uart_loop
+
+        lb a3, 0(a0) // read the next character in hello_msg
+        sw a3, 0(a1) // Write the current character.
+        addi a0, a0, 1 // increment the pointer.
+        bne  a0, a2, uart_loop
+
+gpio_init:   
+	li a0, GPIO_BASE
+        li t0, 0xFFFF0000
+        sw t0, 4(a0)
+        
+gpio_loop:
+        // For Red LEDs, increment manually.
+	li t0, 0x1
+	sw t0, (a0)
+	li t0, 0x2
+	sw t0, (a0)
+	li t0, 0x4
+	sw t0, (a0)
+	li t0, 0x8
+	sw t0, (a0)
+
+        // For Blue and Green LEDs, sample the switches & buttons
+
+        lw   t0, (a0)
+        srli t0, t0, 16
+	andi t0, t0, 0xFF
+        slli t0, t0, 4
+        sw   t0, (a0)
+
+        j gpio_loop
+
+	.section .rodata
+
+hello_msg_start:
+        .incbin "hello_msg.txt"
+hello_msg_end:  
+                
+cfgstr:
+	.incbin CFG_STRING
diff --git a/bootrom/demo/hello_msg.txt b/bootrom/demo/hello_msg.txt
new file mode 100644
index 0000000..c3cb3f2
--- /dev/null
+++ b/bootrom/demo/hello_msg.txt
@@ -0,0 +1,37 @@
+

+                SIFIVE, INC.

+

+         5555555555555555555555555

+        5555                   5555

+       5555                     5555

+      5555                       5555

+     5555       5555555555555555555555

+    5555       555555555555555555555555

+   5555                             5555

+  5555                               5555

+ 5555                                 5555

+5555555555555555555555555555          55555

+ 55555           555555555           55555

+   55555           55555           55555

+     55555           5           55555

+       55555                   55555

+         55555               55555

+           55555           55555

+             55555       55555

+               55555   55555

+                 555555555

+                   55555

+                     5

+

+           SiFive RISC-V Coreplex

+

+Welcome to the Arty FPGA Freedom E Dev Kit. 

+The red LEDs are blinking very fast and appear

+dim. Try pressing the buttons and switches to control

+the blue and green LEDs. You can try using the

+debugger to step through the boot code.

+

+

+

+

+