Re: [PATCH] generic-loader: remove the ram_size limit when a loading binary file

[Philippe Mathieu-Daudé]

On 10/6/21 13:37, Damien Hedde wrote:
> Right now, we cannot load some binary file if it is bigger than the
> machine's ram size. This limitation only occurs when loading a
> binary file: we can load a corresponding elf file without this
> limitation.
> 
> This is an issue for machines that have small ram or do not use the
> ram_size feature at all.
> 
> Also get rid of "hw/boards.h" include, since we needed it only
> to access `current_machine`.
> 
> Fixes: e481a1f63c9 ("generic-loader: Add a generic loader")
> Signed-off-by: Damien Hedde <damien.hedde@greensocs.com>
> ---
> 
> Hi Alistair,
> 
> I found this while experimenting with a ram_size=0 machine.

Where are you loading your file?

> 
> I checked the original discussion: it seems to me there was no
> intention to specifically limit to the ram size but we had to
> put some limit.
> 
> See this:
> https://lists.gnu.org/archive/html/qemu-devel/2016-02/msg04668.html
> https://lists.gnu.org/archive/html/qemu-devel/2016-02/msg04681.html
> 
> Thanks for your feedback,
> Damien
> ---
>  hw/core/generic-loader.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/hw/core/generic-loader.c b/hw/core/generic-loader.c
> index d14f932eea..102605c07b 100644
> --- a/hw/core/generic-loader.c
> +++ b/hw/core/generic-loader.c
> @@ -34,7 +34,6 @@
>  #include "hw/core/cpu.h"
>  #include "sysemu/dma.h"
>  #include "sysemu/reset.h"
> -#include "hw/boards.h"
>  #include "hw/loader.h"
>  #include "hw/qdev-properties.h"
>  #include "qapi/error.h"
> @@ -153,8 +152,8 @@ static void generic_loader_realize(DeviceState *dev, 
> Error **errp)
>          }
>  
>          if (size < 0 || s->force_raw) {
> -            /* Default to the maximum size being the machine's ram size */
> -            size = load_image_targphys_as(s->file, s->addr, 
> current_machine->ram_size, as);
> +            /* Do not limit the file size */
> +            size = load_image_targphys_as(s->file, s->addr, -1, as);
>          } else {
>              s->addr = entry;
>          }
>