Re: [kvm-unit-tests PATCH v6 19/32] lib/efi: Add support for reading an FDT

[Nikos Nikoleris <nikos.nikoleris@xxxxxxx>]

On 08/06/2023 07:55, Andrew Jones wrote:
> On Wed, Jun 07, 2023 at 06:58:22PM +0200, Andrew Jones wrote:
> > On Tue, May 30, 2023 at 05:09:11PM +0100, Nikos Nikoleris wrote:
> > ...
> > > +static void* efi_get_var(efi_handle_t handle, struct efi_loaded_image_64 *image, efi_char16_t *var)
> > > +{
> > > +	efi_status_t status = EFI_SUCCESS;
> > > +	void *val = NULL;
> > > +	uint64_t val_size = 100;
> > > +	efi_guid_t efi_var_guid = EFI_VAR_GUID;
> > > +
> > > +	while (efi_grow_buffer(&status, &val, val_size))
> > > +		status = efi_rs_call(get_variable, var, &efi_var_guid, NULL, &val_size, val);
> > > +
> > > +	return val;
> > > +}
> >
> > I made the following changes to the above function
> >
> >      @@ lib/efi.c: static char *efi_convert_cmdline(struct efi_loaded_image_64 *image, i
> >       +  uint64_t val_size = 100;
> >       +  efi_guid_t efi_var_guid = EFI_VAR_GUID;
> >       +
> >      -+  while (efi_grow_buffer(&status, &val, val_size))
> >      ++  while (efi_grow_buffer(&status, &val, val_size + 1))
>
> I just fixed this fix by changing the '+ 1' to '+ sizeof(efi_char16_t)'
> and then force pushed arm/queue.
>
> Thanks,
> drew

Thanks Drew, I missed this.

Thanks,

Nikos

> >       +          status = efi_rs_call(get_variable, var, &efi_var_guid, NULL, &val_size, val);
> >       +
> >      ++  if (val)
> >      ++          ((efi_char16_t *)val)[val_size / sizeof(efi_char16_t)] = L'\0';
> >      ++
> >       +  return val;
> >       +}
> >       +
> >
> > Before ensuring the dtb pathname was nul-terminated efi_load_image()
> > was reading garbage and unable to find the dtb file.
> >
> > Thanks,
> > drew
> >
> >
> > > +
> > > +static void *efi_get_fdt(efi_handle_t handle, struct efi_loaded_image_64 *image)
> > > +{
> > > +	efi_char16_t var[] = ENV_VARNAME_DTBFILE;
> > > +	efi_char16_t *val;
> > > +	void *fdt = NULL;
> > > +	int fdtsize;
> > > +
> > > +	val = efi_get_var(handle, image, var);
> > > +	if (val)
> > > +		efi_load_image(handle, image, &fdt, &fdtsize, val);
> > > +
> > > +	return fdt;
> > > +}
> > > +
> > >   efi_status_t efi_main(efi_handle_t handle, efi_system_table_t *sys_tab)
> > >   {
> > >   	int ret;
> > > @@ -211,6 +330,7 @@ efi_status_t efi_main(efi_handle_t handle, efi_system_table_t *sys_tab)
> > >   	}
> > >   	setup_args(cmdline_ptr);
> > >   
> > > +	efi_bootinfo.fdt = efi_get_fdt(handle, image);
> > >   	/* Set up efi_bootinfo */
> > >   	efi_bootinfo.mem_map.map = ↦
> > >   	efi_bootinfo.mem_map.map_size = &map_size;
> > > --
> > > 2.25.1