Re: [PATCH v4 16/17] libxl: build a device tree for ARM guests

[Julien Grall <julien.grall@linaro.org>]

On 11/12/2013 05:39 PM, Ian Campbell wrote:
> Uses xc_dom_devicetree_mem which was just added. The call to this needs to be
> carefully sequenced to be after xc_dom_parse_image (so we can tell which kind
> of guest we are building, although we don't use this yet) and before
> xc_dom_mem_init which tries to decide where to place the FDT in guest RAM.
>
> Removes libxl_noarch which would only have been used by IA64 after this
> change. Remove IA64 as part of this patch.
>
> There is no attempt to expose this as a configuration setting for the user.
>
> Includes a debug hook to dump the dtb to a file for inspection.
>
> TODO:
> - v7 CPU compat is hardcoded to cortex-a15 -- may need to define something more
>    generic via mach-virt dt bindngs?
>
> Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
> Cc: Ian Jackson <ian.jackson@eu.citrix.com>
> ---
> v4: Drop spurious comment in header
>      s/__be32/be32/ and s/gic_interrupt_t/gic_interrupt/ to avoid reserved names
>      Coding style fixes
>      Use GCSPRINTF
>      use for(;;) around FDT creation loop, undef FDT when done
>      use libxl__realloc for fdt size increase
>      Refactor debug dump into its own function, remove NDEBUG ifdef
> v2: base addresses, irq, evtchn etc stuff is now from public API headers,
>      avoiding the need to introduce domctls etc until we want to make them
>      dynamic.
>      fix memory node
>      Improve libfdt error handling, especially for FDT_ERR_NOSPACE.
>      Derive guest CPU and timer compatiblity nodes from the guest type.
> ---
>   tools/libxl/Makefile       |    6 +-
>   tools/libxl/libxl_arch.h   |    3 +
>   tools/libxl/libxl_arm.c    |  516 ++++++++++++++++++++++++++++++++++++++++++++
>   tools/libxl/libxl_dom.c    |    4 +
>   tools/libxl/libxl_noarch.c |    8 -
>   tools/libxl/libxl_x86.c    |    7 +
>   6 files changed, 534 insertions(+), 10 deletions(-)
>   create mode 100644 tools/libxl/libxl_arm.c
>   delete mode 100644 tools/libxl/libxl_noarch.c

[..]

> diff --git a/tools/libxl/libxl_arm.c b/tools/libxl/libxl_arm.c
> new file mode 100644
> index 0000000..9fe9a81
> --- /dev/null
> +++ b/tools/libxl/libxl_arm.c
> @@ -0,0 +1,516 @@
> +#include "libxl_internal.h"
> +#include "libxl_arch.h"
> +
> +#include <xc_dom.h>
> +#include <libfdt.h>
> +#include <assert.h>
> +
> +int libxl__arch_domain_create(libxl__gc *gc, libxl_domain_config *d_config,
> +                              uint32_t domid)
> +{
> +    return 0;
> +}
> +
> +static struct arch_info {
> +    const char *guest_type;
> +    const char *timer_compat;
> +    const char *cpu_compat;
> +} arch_info[] = {
> +    {"xen-3.0-armv7l",  "arm,armv7-timer", "arm,cortex-a15" },

What about "arm,armv7" instead arm,cortex-a15? It's more accurate as 
it's possible to boot Xen on cortex-a7 core.

-- 
Julien Grall