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

[Nikos Nikoleris <nikos.nikoleris@arm.com>]

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
>>>