From: Sebastien Bourdeauducq Date: Sun, 5 Feb 2012 19:01:28 +0000 (+0100) Subject: BIOS: hello world X-Git-Tag: 24jan2021_ls180~3262 X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=45529d5941f50870b91cfeea19f04f0824f2d0bd;p=litex.git BIOS: hello world --- diff --git a/software/bios/Makefile b/software/bios/Makefile new file mode 100644 index 00000000..5a5ac66d --- /dev/null +++ b/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 .*~ *~ diff --git a/software/bios/crt0.S b/software/bios/crt0.S new file mode 100644 index 00000000..62797209 --- /dev/null +++ b/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 diff --git a/software/bios/isr.c b/software/bios/isr.c new file mode 100644 index 00000000..25badec3 --- /dev/null +++ b/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 . + */ + +#include +#include + +void isr(void) +{ + unsigned int irqs; + irqs = irq_pending() & irq_getmask(); +} diff --git a/software/bios/linker.ld b/software/bios/linker.ld new file mode 100644 index 00000000..f1d4cc1b --- /dev/null +++ b/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); diff --git a/software/bios/main.c b/software/bios/main.c new file mode 100644 index 00000000..c479dfcf --- /dev/null +++ b/software/bios/main.c @@ -0,0 +1,16 @@ +#include + +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); +} diff --git a/software/include.mak b/software/include.mak index f417bba0..e7129063 100644 --- a/software/include.mak +++ b/software/include.mak @@ -34,8 +34,8 @@ endif # Toolchain options # -INCLUDES_NOLIBC ?= -nostdinc -I$(MMDIR)/software/include/base -INCLUDES = $(INCLUDES_NOLIBC) -I$(MMDIR)/software/include -I$(MMDIR)/tools +INCLUDES_NOLIBC ?= -nostdinc -I$(M2DIR)/software/include/base +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 \ diff --git a/software/libbase/Makefile b/software/libbase/Makefile index b01fc7f9..0ee64cc6 100644 --- a/software/libbase/Makefile +++ b/software/libbase/Makefile @@ -1,13 +1,13 @@ -MMDIR=../.. -include $(MMDIR)/software/include.mak +M2DIR=../.. +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 .*~ *~