Unverified Commit c0fbcd99 authored by Anup Patel's avatar Anup Patel Committed by Palmer Dabbelt
Browse files

RISC-V: Build flat and compressed kernel images 



This patch extends Linux RISC-V build system to build and install:
Image - Flat uncompressed kernel image
Image.gz - Flat and GZip compressed kernel image

Quiet a few bootloaders (such as Uboot, UEFI, etc) are capable of
booting flat and compressed kernel images. In case of Uboot, booting
Image or Image.gz is achieved using bootm command.

The flat and uncompressed kernel image (i.e. Image) is very useful
in pre-silicon developent and testing because we can create back-door
HEX files for RAM on FPGAs from Image.

Signed-off-by: default avatarAnup Patel <anup@brainfault.org>
Signed-off-by: default avatarPalmer Dabbelt <palmer@sifive.com>
parent 21f70d4a

arch/riscv/Makefile

+14 −1
Original line number Diff line number Diff line
@@ -71,6 +71,10 @@ KBUILD_CFLAGS += $(call cc-option,-mstrict-align) 
# arch specific predefines for sparse

CHECKFLAGS += -D__riscv -D__riscv_xlen=$(BITS)



# Default target when executing plain make

boot		:= arch/riscv/boot

KBUILD_IMAGE	:= $(boot)/Image.gz



head-y := arch/riscv/kernel/head.o



core-y += arch/riscv/kernel/ arch/riscv/mm/
@@ -81,4 +85,13 @@ PHONY += vdso_install 
vdso_install:

	$(Q)$(MAKE) $(build)=arch/riscv/kernel/vdso $@



all: vmlinux
 
all: Image.gz



Image: vmlinux

	$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@



Image.%: Image

	$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@



zinstall install:

	$(Q)$(MAKE) $(build)=$(boot) $@

arch/riscv/boot/.gitignore

0 → 100644
+2 −0
Original line number Diff line number Diff line 
Image

Image.gz

arch/riscv/boot/Makefile

0 → 100644
+33 −0
Original line number Diff line number Diff line 
#

# arch/riscv/boot/Makefile

#

# This file is included by the global makefile so that you can add your own

# architecture-specific flags and dependencies.

#

# This file is subject to the terms and conditions of the GNU General Public

# License.  See the file "COPYING" in the main directory of this archive

# for more details.

#

# Copyright (C) 2018, Anup Patel.

# Author: Anup Patel <anup@brainfault.org>

#

# Based on the ia64 and arm64 boot/Makefile.

#



OBJCOPYFLAGS_Image :=-O binary -R .note -R .note.gnu.build-id -R .comment -S



targets := Image



$(obj)/Image: vmlinux FORCE

	$(call if_changed,objcopy)



$(obj)/Image.gz: $(obj)/Image FORCE

	$(call if_changed,gzip)



install:

	$(CONFIG_SHELL) $(srctree)/$(src)/install.sh $(KERNELRELEASE) \

	$(obj)/Image System.map "$(INSTALL_PATH)"



zinstall:

	$(CONFIG_SHELL) $(srctree)/$(src)/install.sh $(KERNELRELEASE) \

	$(obj)/Image.gz System.map "$(INSTALL_PATH)"

arch/riscv/boot/install.sh

0 → 100644
+60 −0
Original line number Diff line number Diff line 
#!/bin/sh

#

# arch/riscv/boot/install.sh

#

# This file is subject to the terms and conditions of the GNU General Public

# License.  See the file "COPYING" in the main directory of this archive

# for more details.

#

# Copyright (C) 1995 by Linus Torvalds

#

# Adapted from code in arch/i386/boot/Makefile by H. Peter Anvin

# Adapted from code in arch/i386/boot/install.sh by Russell King

#

# "make install" script for the RISC-V Linux port

#

# Arguments:

#   $1 - kernel version

#   $2 - kernel image file

#   $3 - kernel map file

#   $4 - default install path (blank if root directory)

#



verify () {

	if [ ! -f "$1" ]; then

		echo ""                                                   1>&2

		echo " *** Missing file: $1"                              1>&2

		echo ' *** You need to run "make" before "make install".' 1>&2

		echo ""                                                   1>&2

		exit 1

	fi

}



# Make sure the files actually exist

verify "$2"

verify "$3"



# User may have a custom install script

if [ -x ~/bin/${INSTALLKERNEL} ]; then exec ~/bin/${INSTALLKERNEL} "$@"; fi

if [ -x /sbin/${INSTALLKERNEL} ]; then exec /sbin/${INSTALLKERNEL} "$@"; fi



if [ "$(basename $2)" = "Image.gz" ]; then

# Compressed install

  echo "Installing compressed kernel"

  base=vmlinuz

else

# Normal install

  echo "Installing normal kernel"

  base=vmlinux

fi



if [ -f $4/$base-$1 ]; then

  mv $4/$base-$1 $4/$base-$1.old

fi

cat $2 > $4/$base-$1



# Install system map file

if [ -f $4/System.map-$1 ]; then

  mv $4/System.map-$1 $4/System.map-$1.old

fi

cp $3 $4/System.map-$1

arch/riscv/kernel/head.S

+10 −0
Original line number Diff line number Diff line
@@ -44,6 +44,16 @@ ENTRY(_start) 
	amoadd.w a3, a2, (a3)

	bnez a3, .Lsecondary_start



	/* Clear BSS for flat non-ELF images */

	la a3, __bss_start

	la a4, __bss_stop

	ble a4, a3, clear_bss_done

clear_bss:

	REG_S zero, (a3)

	add a3, a3, RISCV_SZPTR

	blt a3, a4, clear_bss

clear_bss_done:



	/* Save hart ID and DTB physical address */

	mv s0, a0

	mv s1, a1

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