BIOS: hello world

software/bios/Makefile

@@ -0,0 +1,30 @@
+M2DIR=../..
+include $(M2DIR)/software/include.mak
+
+OBJECTS=crt0.o isr.o main.o
+
+all: bios.bin
+
+# pull in dependency info for *existing* .o files
+-include $(OBJECTS:.o=.d)
+
+%.bin: %.elf
+	$(MAKE) -C $(M2DIR)/tools
+	$(OBJCOPY) -O binary $< $@
+	chmod -x $@
+	$(M2DIR)/tools/mkmmimg $@ write
+
+bios.elf: linker.ld $(OBJECTS) libs
+bios-rescue.elf: linker-rescue.ld $(OBJECTS) libs
+
+%.elf:
+	$(LD) $(LDFLAGS) -T $< -N -o $@ $(OBJECTS) -L$(M2DIR)/software/libbase -lbase
+	chmod -x $@
+
+libs:
+	make -C $(M2DIR)/software/libbase
+
+.PHONY: clean libs
+
+clean:
+	rm -f $(OBJECTS) $(OBJECTS:.o=.d) bios.elf bios.bin bios-rescue.elf bios-rescue.bin .*~ *~

software/bios/crt0.S

@@ -0,0 +1,167 @@
+/*
+ * LatticeMico32 C startup code.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/* Exception handlers - Must be 32 bytes long. */
+.section    .text, "ax", @progbits
+.global     _start
+_start:
+_reset_handler:
+	xor	r0, r0, r0
+	wcsr	IE, r0
+	mvhi	r1, hi(_reset_handler)
+	ori	r1, r1, lo(_reset_handler)
+	wcsr	EBA, r1
+	bi	_crt0
+	nop
+	nop
+
+_breakpoint_handler:
+	bi _breakpoint_handler
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+
+_instruction_bus_error_handler:
+	bi _instruction_bus_error_handler
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+
+_watchpoint_hander:
+	bi _watchpoint_hander
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+
+_data_bus_error_handler:
+	bi _data_bus_error_handler
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+
+_divide_by_zero_handler:
+	bi _divide_by_zero_handler
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+
+_interrupt_handler:
+	sw      (sp+0), ra
+	calli   .save_all
+	calli   isr
+	bi      .restore_all_and_eret
+	nop
+	nop
+	nop
+	nop
+
+macaddress:
+	.byte 0x10
+	.byte 0xe2
+	.byte 0xd5
+	.byte 0x00
+	.byte 0x00
+	.byte 0x00
+
+	/* padding to align to a 32-bit boundary */
+	.byte 0x00
+	.byte 0x00
+
+_crt0:
+	/* Setup stack and global pointer */
+	mvhi    sp, hi(_fstack)
+	ori     sp, sp, lo(_fstack)
+	mvhi    gp, hi(_gp)
+	ori     gp, gp, lo(_gp)
+
+	/* Clear BSS */
+	mvhi    r1, hi(_fbss)
+	ori     r1, r1, lo(_fbss)
+	mvhi    r3, hi(_ebss)
+	ori     r3, r3, lo(_ebss)
+.clearBSS:
+	be      r1, r3, .callMain
+	sw      (r1+0), r0
+	addi    r1, r1, 4
+	bi      .clearBSS
+
+.callMain:
+	bi      main
+
+.save_all:
+	addi    sp, sp, -56
+	sw      (sp+4), r1
+	sw      (sp+8), r2
+	sw      (sp+12), r3
+	sw      (sp+16), r4
+	sw      (sp+20), r5
+	sw      (sp+24), r6
+	sw      (sp+28), r7
+	sw      (sp+32), r8
+	sw      (sp+36), r9
+	sw      (sp+40), r10
+	sw      (sp+48), ea
+	sw      (sp+52), ba
+	/* ra needs to be moved from initial stack location */
+	lw      r1, (sp+56)
+	sw      (sp+44), r1
+	ret
+
+.restore_all_and_eret:
+	lw      r1, (sp+4)
+	lw      r2, (sp+8)
+	lw      r3, (sp+12)
+	lw      r4, (sp+16)
+	lw      r5, (sp+20)
+	lw      r6, (sp+24)
+	lw      r7, (sp+28)
+	lw      r8, (sp+32)
+	lw      r9, (sp+36)
+	lw      r10, (sp+40)
+	lw      ra, (sp+44)
+	lw      ea, (sp+48)
+	lw      ba, (sp+52)
+	addi    sp, sp, 56
+	eret

software/bios/isr.c

@@ -0,0 +1,25 @@
+/*
+ * Milkymist SoC (Software)
+ * Copyright (C) 2007, 2008, 2009, 2010 Sebastien Bourdeauducq
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 3 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <hw/interrupts.h>
+#include <irq.h>
+
+void isr(void)
+{
+	unsigned int irqs;
+	irqs = irq_pending() & irq_getmask();
+}

software/bios/linker.ld

@@ -0,0 +1,57 @@
+OUTPUT_FORMAT("elf32-lm32")
+ENTRY(_start)
+
+__DYNAMIC = 0;
+
+MEMORY {
+	flash : ORIGIN = 0x00860000, LENGTH = 0x20000 /* 128K */
+	sram  : ORIGIN = 0x10000000, LENGTH = 0x01000 /* 4K */
+}
+
+SECTIONS
+{
+	.text :
+	{
+		_ftext = .;
+		*(.text .stub .text.* .gnu.linkonce.t.*)
+		_etext = .;
+	} > flash
+
+	.rodata :
+	{
+		. = ALIGN(4);
+		_frodata = .;
+		*(.rodata .rodata.* .gnu.linkonce.r.*)
+		*(.rodata1)
+		_erodata = .;
+	} > flash
+
+	/* We shouldn't have a .data section, but the GNU crapchain whines if we don't */
+	.data :
+	{
+		. = ALIGN(4);
+		_fdata = .;
+		*(.data .data.* .gnu.linkonce.d.*)
+		*(.data1)
+		_gp = ALIGN(16);
+		*(.sdata .sdata.* .gnu.linkonce.s.*)
+		_edata = .;
+	} > flash
+
+	.bss :
+	{
+		. = ALIGN(4);
+		_fbss = .;
+		*(.dynsbss)
+		*(.sbss .sbss.* .gnu.linkonce.sb.*)
+		*(.scommon)
+		*(.dynbss)
+		*(.bss .bss.* .gnu.linkonce.b.*)
+		*(COMMON)
+		. = ALIGN(4);
+		_ebss = .;
+		_end = .;
+	} > sram
+}
+
+PROVIDE(_fstack = ORIGIN(sram) + LENGTH(sram) - 4);

software/bios/main.c

@@ -0,0 +1,16 @@
+#include <hw/uart.h>
+
+static void print(const char *s)
+{
+	while(*s) {
+		while(!(CSR_UART_STAT & UART_STAT_THRE));
+		CSR_UART_RXTX = *s;
+		s++;
+	}
+}
+
+int main(void)
+{
+	print("Hello World\n");
+	while(1);
+}

software/include.mak

@@ -34,8 +34,8 @@ endif
 
 # Toolchain options
 #
-INCLUDES_NOLIBC ?= -nostdinc -I$(MMDIR)/software/include/base
+INCLUDES_NOLIBC ?= -nostdinc -I$(M2DIR)/software/include/base
-INCLUDES = $(INCLUDES_NOLIBC) -I$(MMDIR)/software/include -I$(MMDIR)/tools
+INCLUDES = $(INCLUDES_NOLIBC) -I$(M2DIR)/software/include -I$(M2DIR)/tools
 ASFLAGS = $(INCLUDES) -nostdinc
 # later: -Wmissing-prototypes
 CFLAGS = -O9 -Wall -Wstrict-prototypes -Wold-style-definition -Wshadow \

software/libbase/Makefile

@@ -1,13 +1,13 @@
-MMDIR=../..
+M2DIR=../..
-include $(MMDIR)/software/include.mak
+include $(M2DIR)/software/include.mak
 
 OBJECTS=divsi3.o libc.o console.o system.o board.o uart.o softfloat.o softfloat-glue.o vsnprintf.o atof.o
 
+all: libbase.a
+
 # pull in dependency info for *existing* .o files
 -include $(OBJECTS:.o=.d)
 
-all: libbase.a
-
 libbase.a: $(OBJECTS)
 	$(AR) clr libbase.a $(OBJECTS)
 	$(RANLIB) libbase.a
@@ -15,4 +15,4 @@ libbase.a: $(OBJECTS)
 .PHONY: clean
 
 clean:
-	rm -f $(OBJECTS) $(OBJECTS:.o=.d) libbase.a .*~ *~ Makefile.bak
+	rm -f $(OBJECTS) $(OBJECTS:.o=.d) libbase.a .*~ *~