On 19/11/15 16:22, Eric Auger wrote:
> This function returns the host device tree blob from sysfs
> (/sys/firmware/devicetree/base).
>
> This has a runtime dependency on the dtc binary. This functionality
> is useful for platform device passthrough where the host device tree
> needs to be parsed to feed information into the guest device tree.
>
> Signed-off-by: Eric Auger <eric.au...@linaro.org>
> ---
> device_tree.c | 40 ++++++++++++++++++++++++++++++++++++++++
> include/sysemu/device_tree.h | 1 +
> 2 files changed, 41 insertions(+)
>
> diff --git a/device_tree.c b/device_tree.c
> index a9f5f8e..58a5329 100644
> --- a/device_tree.c
> +++ b/device_tree.c
> @@ -117,6 +117,46 @@ fail:
> return NULL;
> }
>
> +/**
> + * load_device_tree_from_sysfs
> + *
> + * extract the dt blob from host sysfs
> + * this has a runtime dependency on the dtc binary
> + */
> +void *load_device_tree_from_sysfs(void)
> +{
> + char cmd[] = "dtc -I fs -O dtb /sys/firmware/devicetree/base";
> + FILE *pipe;
> + void *fdt;
> + int ret, actual_dt_size;
> +
> + pipe = popen(cmd, "r");
> + if (!pipe) {
> + error_report("%s: Error when executing dtc", __func__);
> + return NULL;
> + }
The Device Tree Compiler binary is normally only installed on
developer's machines, so I somewhat doubt that it is a good idea to rely
on the availability of that binary in QEMU? Maybe you should rather
extend libfdt to support such a feature?
Thomas
