[PATCH v7 1/8] efi_loader: remove unused code from copy_fdt()

[Heinrich Schuchardt]

On 11.03.25 14:21, Ilias Apalodimas wrote:
> Heinrich, do you remember why this was originally here?
>   I looked at 6422820ac3e59 which moved that code around, but the same
> code was there as well
> 
> On Mon, 10 Mar 2025 at 13:58, Sughosh Ganu <sughosh.ganu at linaro.org> wrote:
>>
>> There is logic in the copy_fdt() function which is iterating over the
>> platform's DRAM banks and setting the fdt_ram_start variable. However,
>> this variable is not used subsequently in the function. Remove this
>> superfluous code.
>>
>> Signed-off-by: Sughosh Ganu <sughosh.ganu at linaro.org>
>> ---
>> Changes since V6: New patch
>>
>>   lib/efi_loader/efi_helper.c | 14 +-------------
>>   1 file changed, 1 insertion(+), 13 deletions(-)
>>
>> diff --git a/lib/efi_loader/efi_helper.c b/lib/efi_loader/efi_helper.c
>> index 04b2efc4a3b..15ad042bc61 100644
>> --- a/lib/efi_loader/efi_helper.c
>> +++ b/lib/efi_loader/efi_helper.c
>> @@ -454,23 +454,11 @@ efi_status_t efi_env_set_load_options(efi_handle_t handle,
>>    */
>>   static efi_status_t copy_fdt(void **fdtp)
>>   {
>> -       unsigned long fdt_ram_start = -1L, fdt_pages;
>> +       unsigned long fdt_pages;
>>          efi_status_t ret = 0;
>>          void *fdt, *new_fdt;
>>          u64 new_fdt_addr;
>>          uint fdt_size;
>> -       int i;
>> -
>> -       for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) {
>> -               u64 ram_start = gd->bd->bi_dram[i].start;
>> -               u64 ram_size = gd->bd->bi_dram[i].size;
>> -
>> -               if (!ram_size)
>> -                       continue;
>> -
>> -               if (ram_start < fdt_ram_start)
>> -                       fdt_ram_start = ram_start;
>> -       }

The removed code was introduced by Alex in 2016 with patch
ad0c1a3d2cea ("efi_loader: Put fdt into convenient location").

Writing the device-tree at the start of RAM may have worked for some 
boards at the time but on many others this would be inside reserved memory.

Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>

>>
>>          /*
>>           * Give us at least 12 KiB of breathing room in case the device tree
>> --
>> 2.34.1
>>
> 
> Reviewed-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>