[PATCH] cmd: fdt: use U-Boot's FDT by default

[Caleb Connolly]

On 03/09/2024 20:14, Tom Rini wrote:
> On Sat, Aug 31, 2024 at 05:46:19PM +0100, Caleb Connolly wrote:
> 
>> When using the FDT command to inspect an arbitrary FDT in memory, it
>> will always be necessary to explicitly set the FDT address. However it
>> is also quite likely that the command is being used to inspect U-Boot's
>> own FDT. Simplify that common workflow of running "fdt addr -c" to get
>> the control address and set it by just making $fdtcontroladdr the
>> default FDT if there isn't one.
>>
>> Signed-off-by: Caleb Connolly <caleb.connolly at linaro.org>
>> ---
>>   cmd/fdt.c | 9 +++++++++
>>   1 file changed, 9 insertions(+)
>>
>> diff --git a/cmd/fdt.c b/cmd/fdt.c
>> index d16b141ce32d..8909706e2483 100644
>> --- a/cmd/fdt.c
>> +++ b/cmd/fdt.c
>> @@ -276,8 +276,17 @@ static int do_fdt(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
>>   
>>   		return CMD_RET_SUCCESS;
>>   	}
>>   
>> +	/* Try using U-Boot's FDT by default */
>> +	if (!working_fdt) {
>> +		struct fdt_header *addr;
>> +
>> +		addr = (void *)env_get_hex("fdtcontroladdr", 0);
>> +		if (addr && fdt_check_header(&addr))
>> +			set_working_fdt_addr((phys_addr_t)addr);
>> +	}
>> +
>>   	if (!working_fdt) {
>>   		puts("No FDT memory address configured. Please configure\n"
>>   		     "the FDT address via \"fdt addr <address>\" command.\n"
>>   		     "Aborting!\n");
> 
> Setting aside the behavior change (which I am thinking about), this
> makes the next check of !working_fdt dead code which should be removed.

I wasn't sure if we could safely assume that fdtcontroladdr always 
points to a valid FDT, if that's true then yes this can be dropped.
> 

-- 
// Caleb (they/them)