Hi Rob, On 02/01/2016 05:15 PM, Rob Herring wrote: > On Mon, Feb 1, 2016 at 7:51 AM, Eric Auger <eric.au...@linaro.org> wrote: >> This function returns the host device tree blob from sysfs >> (/proc/device-tree). It uses a recursive function inspired >> from dtc read_fstree. >> >> Signed-off-by: Eric Auger <eric.au...@linaro.org> >> >> --- >> v5 -> v6: >> - fix some spelling mistakes >> - error_report + exit replaced by error_setg >> - const char *parent_node; >> - use g_strdup_printf instead of g_strjoin >> - add a doc comment for load_device_tree_from_sysfs >> v1 -> v2: >> - do not implement/expose read_fstree and load_device_tree_from_sysfs >> if CONFIG_LINUX is not defined (lstat is not implemeted in mingw) >> - correct indentation in read_fstree >> - use /proc/device-tree symlink instead of /sys/firmware/devicetree/base >> path (kernel.org/doc/Documentation/ABI/testing/sysfs-firmware-ofw) >> - use g_file_get_contents in read_fstree >> - introduce SYSFS_DT_BASEDIR macro and use strlen >> - exit on error in load_device_tree_from_sysfs >> - user error_setg >> >> RFC -> v1: >> - remove runtime dependency on dtc binary and introduce read_fstree >> --- >> device_tree.c | 99 >> ++++++++++++++++++++++++++++++++++++++++++++ >> include/sysemu/device_tree.h | 8 ++++ >> 2 files changed, 107 insertions(+) >> >> diff --git a/device_tree.c b/device_tree.c >> index a9f5f8e..3797182 100644 >> --- a/device_tree.c >> +++ b/device_tree.c >> @@ -17,6 +17,9 @@ >> #include <fcntl.h> >> #include <unistd.h> >> #include <stdlib.h> >> +#ifdef CONFIG_LINUX >> +#include <dirent.h> >> +#endif >> >> #include "qemu-common.h" >> #include "qemu/error-report.h" >> @@ -117,6 +120,102 @@ fail: >> return NULL; >> } >> >> +#ifdef CONFIG_LINUX >> + >> +#define SYSFS_DT_BASEDIR "/proc/device-tree" > > Use the sysfs path (/sys/firmware/device-tree/ IIRC) as this is just a > symlink to sysfs and /proc is considered the legacy path. I used the sysfs originally but I eventually found: https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-firmware-ofw which states:
"Userspace must not use the /sys/firmware/devicetree/base path directly, but instead should follow /proc/device-tree symlink. It is possible that the absolute path will change in the future, but the symlink is the stable ABI. " Do you confirm this statement is outdated. Thank you in advance Best Regards Eric > > Rob >