Re: [Qemu-devel] [PATCH 0/5] hw/arm/boot: Support DTB autoload for firmware-only boots

[Igor Mammedov <imammedo@redhat.com>]

On Thu, 31 Jan 2019 11:22:35 +0000
Peter Maydell <peter.maydell@linaro.org> wrote:

> The arm_boot_info struct has a skip_dtb_autoload flag: if this is
> set to true by the board code then arm_load_kernel() will not
> load the DTB itself, but will leave this for the board code to
> do itself later. However, the check for this is done in a
> code path which is only executed for the case where we load
> a kernel image file. If we're taking the "boot via firmware"
> code path then the flag isn't honoured and the DTB is never
> loaded.
>     
> We didn't notice this because the only real user of "boot
> via firmware" that cares about the DTB is the virt board
> (for UEFI boot), and that always wants skip_dtb_autoload
> anyway. But the SBSA reference board model we're planning to
> add will want the flag to behave correctly.
> 
> The first four patches in this set are just refactoring,
> splitting the code in arm_load_kernel() out into a
> couple of sub-functions for "direct kernel boot" and
> "firmware boot". The last patch that fixes the issue is
> then just a one-liner. (Without the refactoring we'd
> need to use a goto, which is what I wanted to avoid.)
> 
> thanks
> -- PMM
> 
> Peter Maydell (5):
>   hw/arm/boot: Fix block comment style in arm_load_kernel()
>   hw/arm/boot: Factor out "direct kernel boot" code into its own
>     function
>   hw/arm/boot: Factor out "set up firmware boot" code
>   hw/arm/boot: Clarify why arm_setup_firmware_boot() doesn't set
>     env->boot_info
>   hw/arm/boot: Support DTB autoload for firmware-only boots
> 
>  hw/arm/boot.c | 166 +++++++++++++++++++++++++++++---------------------
>  1 file changed, 96 insertions(+), 70 deletions(-)
> 

Reviewed-by: Igor Mammedov <imammedo@redhat.com>