Re: [Qemu-devel] [PATCH 5/8] Implement device tree support needed for Bamboo emulation

[Aurelien Jarno]

On Mon, Dec 15, 2008 at 10:44:16AM -0600, Hollis Blanchard wrote:
> To implement the -kernel, -initrd, and -append options, 4xx board emulation
> must load the guest kernel as if firmware had loaded it. Where u-boot would be
> the firmware, we must load the flat device tree into memory and set key fields
> such as /chosen/bootargs.
> 
> This patch introduces a dependency on libfdt for flat device tree support.
> 
> Signed-off-by: Hollis Blanchard <address@hidden>
> ---
>  Makefile.target |    4 ++
>  configure       |   18 +++++++++
>  device_tree.c   |  114 
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  device_tree.h   |   26 ++++++++++++
>  libfdt_env.h    |   41 ++++++++++++++++++++
>  5 files changed, 203 insertions(+), 0 deletions(-)
>  create mode 100644 device_tree.c
>  create mode 100644 device_tree.h
>  create mode 100644 libfdt_env.h
> 
> diff --git a/Makefile.target b/Makefile.target
> index 8229b4f..d80ce2c 100644
> --- a/Makefile.target
> +++ b/Makefile.target
> @@ -655,6 +655,10 @@ OBJS+= heathrow_pic.o grackle_pci.o ppc_oldworld.o
>  OBJS+= unin_pci.o ppc_chrp.o
>  # PowerPC 4xx boards
>  OBJS+= pflash_cfi02.o ppc4xx_devs.o ppc4xx_pci.o ppc405_uc.o ppc405_boards.o
> +ifdef FDT_LIBS
> +OBJS+= device_tree.o
> +LIBS+= $(FDT_LIBS)
> +endif
>  # virtio support
>  OBJS+= virtio.o virtio-blk.o virtio-balloon.o
>  endif
> diff --git a/configure b/configure
> index 455dbef..562f113 100755
> --- a/configure
> +++ b/configure
> @@ -119,6 +119,7 @@ kvm="yes"
>  kerneldir=""
>  aix="no"
>  blobs="yes"
> +fdt="yes"
>  
>  # OS specific
>  targetos=`uname -s`
> @@ -966,6 +967,18 @@ if $cc $ARCH_CFLAGS -o $TMPE $TMPC > /dev/null 2> 
> /dev/null ; then
>    iovec=yes
>  fi
>  
> +##########################################
> +# fdt probe
> +if test "$fdt" = "yes" ; then
> +    fdt=no
> +    cat > $TMPC << EOF
> +int main(void) { return 0; }
> +EOF
> +  if $cc $ARCH_CFLAGS -o $TMPE ${OS_CFLAGS} $TMPC -lfdt 2> /dev/null ; then
> +    fdt=yes
> +  fi
> +fi
> +
>  # Check if tools are available to build documentation.
>  if [ -x "`which texi2html 2>/dev/null`" ] && \
>     [ -x "`which pod2man 2>/dev/null`" ]; then
> @@ -1061,6 +1074,7 @@ echo "vde support       $vde"
>  echo "AIO support       $aio"
>  echo "Install blobs     $blobs"
>  echo "KVM support       $kvm"
> +echo "fdt support       $kvm"

This looks wrong, should probably be $fdt.
  
>  if test $sdl_too_old = "yes"; then
>  echo "-> Your SDL version is too old - please upgrade to have SDL support"
> @@ -1350,6 +1364,10 @@ fi
>  if test "$iovec" = "yes" ; then
>    echo "#define HAVE_IOVEC 1" >> $config_h
>  fi
> +if test "$fdt" = "yes" ; then
> +  echo "#define HAVE_FDT 1" >> $config_h
> +  echo "FDT_LIBS=-lfdt" >> $config_mak
> +fi
>  
>  # XXX: suppress that
>  if [ "$bsd" = "yes" ] ; then
> diff --git a/device_tree.c b/device_tree.c
> new file mode 100644
> index 0000000..2238682
> --- /dev/null
> +++ b/device_tree.c
> @@ -0,0 +1,114 @@
> +/*
> + * Functions to help device tree manipulation using libfdt.
> + * It also provides functions to read entries from device tree proc
> + * interface.
> + *
> + * Copyright 2008 IBM Corporation.
> + * Authors: Jerone Young <address@hidden>
> + *          Hollis Blanchard <address@hidden>
> + *
> + * This work is licensed under the GNU GPL license version 2 or later.
> + *
> + */
> +
> +#include <stdio.h>
> +#include <sys/types.h>
> +#include <sys/stat.h>
> +#include <fcntl.h>
> +#include <unistd.h>
> +#include <stdlib.h>
> +
> +#include "config.h"
> +#include "qemu-common.h"
> +#include "sysemu.h"
> +#include "device_tree.h"
> +
> +#include <libfdt.h>
> +
> +void *load_device_tree(const char *filename_path, void *load_addr)
> +{
> +    int dt_file_size;
> +    int dt_file_load_size;
> +    int new_dt_size;
> +    int ret;
> +    void *dt_file = NULL;
> +    void *fdt;
> +
> +    dt_file_size = get_image_size(filename_path);
> +    if (dt_file_size < 0) {
> +        printf("Unable to get size of device tree file '%s'\n",
> +            filename_path);
> +        goto fail;
> +    }
> +
> +    /* First allocate space in qemu for device tree */
> +    dt_file = qemu_mallocz(dt_file_size);
> +    if (dt_file == NULL) {
> +        printf("Unable to allocate memory in qemu for device tree\n");
> +        goto fail;
> +    }
> +
> +    dt_file_load_size = load_image(filename_path, dt_file);
> +
> +    /* Second we place new copy of 2x size in guest memory
> +     * This give us enough room for manipulation.
> +     */
> +    new_dt_size = dt_file_size * 2;
> +
> +    fdt = load_addr;
> +    ret = fdt_open_into(dt_file, fdt, new_dt_size);
> +    if (ret) {
> +        printf("Unable to copy device tree in memory\n");
> +        goto fail;
> +    }
> +
> +    /* Check sanity of device tree */
> +    if (fdt_check_header(fdt)) {
> +        printf ("Device tree file loaded into memory is invalid: %s\n",
> +            filename_path);
> +        goto fail;
> +    }
> +    /* free qemu memory with old device tree */
> +    qemu_free(dt_file);
> +    return fdt;
> +
> +fail:
> +    qemu_free(dt_file);
> +    return NULL;
> +}
> +
> +int qemu_devtree_setprop(void *fdt, const char *node_path,
> +                         const char *property, uint32_t *val_array, int size)
> +{
> +    int offset;
> +
> +    offset = fdt_path_offset(fdt, node_path);
> +    if (offset < 0)
> +        return offset;
> +
> +    return fdt_setprop(fdt, offset, property, val_array, size);
> +}
> +
> +int qemu_devtree_setprop_cell(void *fdt, const char *node_path,
> +                              const char *property, uint32_t val)
> +{
> +    int offset;
> +
> +    offset = fdt_path_offset(fdt, node_path);
> +    if (offset < 0)
> +        return offset;
> +
> +    return fdt_setprop_cell(fdt, offset, property, val);
> +}
> +
> +int qemu_devtree_setprop_string(void *fdt, const char *node_path,
> +                                const char *property, const char *string)
> +{
> +    int offset;
> +
> +    offset = fdt_path_offset(fdt, node_path);
> +    if (offset < 0)
> +        return offset;
> +
> +    return fdt_setprop_string(fdt, offset, property, string);
> +}
> diff --git a/device_tree.h b/device_tree.h
> new file mode 100644
> index 0000000..9e6ef3d
> --- /dev/null
> +++ b/device_tree.h
> @@ -0,0 +1,26 @@
> +/*
> + * Header with function prototypes to help device tree manipulation using
> + * libfdt. It also provides functions to read entries from device tree proc
> + * interface.
> + *
> + * Copyright 2008 IBM Corporation.
> + * Authors: Jerone Young <address@hidden>
> + *          Hollis Blanchard <address@hidden>
> + *
> + * This work is licensed under the GNU GPL license version 2 or later.
> + *
> + */
> +
> +#ifndef __DEVICE_TREE_H__
> +#define __DEVICE_TREE_H__
> +
> +void *load_device_tree(const char *filename_path, void *load_addr);
> +
> +int qemu_devtree_setprop(void *fdt, const char *node_path,
> +                         const char *property, uint32_t *val_array, int 
> size);
> +int qemu_devtree_setprop_cell(void *fdt, const char *node_path,
> +                              const char *property, uint32_t val);
> +int qemu_devtree_setprop_string(void *fdt, const char *node_path,
> +                                const char *property, const char *string);
> +
> +#endif /* __DEVICE_TREE_H__ */
> diff --git a/libfdt_env.h b/libfdt_env.h
> new file mode 100644
> index 0000000..e154b8e
> --- /dev/null
> +++ b/libfdt_env.h
> @@ -0,0 +1,41 @@
> +/*
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License, version 2, as
> + * published by the Free Software Foundation.
> + *
> + * 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, write to the Free Software
> + * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
> + *
> + * Copyright IBM Corp. 2008
> + * Authors: Hollis Blanchard <address@hidden>
> + *
> + */
> +
> +#ifndef _LIBFDT_ENV_H
> +#define _LIBFDT_ENV_H
> +
> +#include <stddef.h>
> +#include <stdint.h>
> +#include <string.h>
> +#include <endian.h>
> +#include <byteswap.h>
> +
> +#if __BYTE_ORDER == __BIG_ENDIAN
> +#define fdt32_to_cpu(x)              (x)
> +#define cpu_to_fdt32(x)              (x)
> +#define fdt64_to_cpu(x)              (x)
> +#define cpu_to_fdt64(x)              (x)
> +#else
> +#define fdt32_to_cpu(x)              (bswap_32((x)))
> +#define cpu_to_fdt32(x)              (bswap_32((x)))
> +#define fdt64_to_cpu(x)              (bswap_64((x)))
> +#define cpu_to_fdt64(x)              (bswap_64((x)))
> +#endif
> +
> +#endif /* _LIBFDT_ENV_H */
> -- 
> 1.5.6.5
> 
> 
> 
> 

-- 
  .''`.  Aurelien Jarno             | GPG: 1024D/F1BCDB73
 : :' :  Debian developer           | Electrical Engineer
 `. `'   address@hidden         | address@hidden
   `-    people.debian.org/~aurel32 | www.aurel32.net