Re: [PATCH 2/3] blspec: add new blspec.compatible.extra variable

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

Hi,

On 21.09.23 14:37, Ahmad Fatoum wrote:
> On 20.09.23 14:37, Rouven Czerwinski wrote:
>> The blspec.compatible.extra variable will be used to specify extra
> 
> As this is only relevant when booting. Maybe prefix with boot.?
> Not sure if that wouldn't be too long..

We may also want to use this for other stuff than blspec in future,
e.g. FIT or matching overlays by compatible, so I think we should do away
with both blspec and boot and call it maybe global.of.compatible.extra?

If you agree, please define the variable in common/misc.c or some other
common location.

> 
>> compatibles that are also used to match during bootloader specification
>> entry parsing. This means that even if your internal barebox device tree
>> machine compatible is "vendor,bareboxcompatible", but your bootloader
>> specification device tree contains "vendor,linuxcompatible", it is
>> possible to boot this entry by setting blspec.compatible.extra to
>> "vendor,linuxcompatible".
>>
>> More than one compatible is possible as well, the compatibles will need
>> to be space separated (since "," is already used for the vendor hardware
>> distinction).
>>
>> Signed-off-by: Rouven Czerwinski <r.czerwinski@pengutronix.de>
>> ---
>>  common/blspec.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++
>>  1 file changed, 56 insertions(+)
>>
>> diff --git a/common/blspec.c b/common/blspec.c
>> index f8d47f20d2..e361a02333 100644
>> --- a/common/blspec.c
>> +++ b/common/blspec.c
>> @@ -19,10 +19,20 @@
>>  #include <net.h>
>>  #include <fs.h>
>>  #include <of.h>
>> +#include <magicvar.h>
>> +#include <linux/list.h>
>>  #include <linux/stat.h>
>>  #include <linux/err.h>
>>  #include <mtd/ubi-user.h>
>>  
>> +struct list_head *blspec_extra_list;
>> +char *blspec_extra_string;
>> +
>> +struct blspec_extra_entry {
>> +	char *compatible;
>> +	struct list_head list;
>> +};
>> +
>>  /*
>>   * blspec_entry_var_set - set a variable to a value
>>   */
>> @@ -830,8 +840,54 @@ static int blspec_bootentry_provider(struct bootentries *bootentries,
>>  	return found;
>>  }
>>  
>> +static int blspec_extra_set(struct param_d *p, void *priv)
>> +{
>> +	struct blspec_extra_entry *entry, *tmp;
>> +	char *str = blspec_extra_string;
>> +	char *temp = str;
>> +	unsigned int len;
>> +
>> +	if (blspec_extra_list) {
>> +		list_for_each_entry_safe(entry, tmp, blspec_extra_list, list) {
>> +			list_del(&entry->list);
>> +			free(entry->compatible);
>> +			free(entry);
>> +		}
>> +		blspec_extra_list = NULL;
>> +	}
>> +
>> +	while(str++) {
>> +		if (*str == ' ' || *str == 0) {
> 
> Please use strsep (or strsep_unescaped) as elsewhere in blspec.c. 
> 
>> +			len = temp - str;
>> +			if(len > 126) {
>> +				len = 127;
>> +			}
>> +			entry = calloc(1, sizeof(struct blspec_extra_entry));
> 
> xzalloc if you don't check for !NULL.
> 
>> +			entry->compatible = xzalloc(len + 1);
>> +			memcpy(entry->compatible, temp, len);
> 
> But here you could just use xstrdup?
> 
>> +
>> +			if (blspec_extra_list == NULL) {
>> +				INIT_LIST_HEAD(&entry->list);
>> +				blspec_extra_list = &entry->list;
> 
> This is unusal. Why not have blspec_extra_list be a list_head instead of a pointer?
> 
>> +			} else {
>> +				list_add_tail(&entry->list, blspec_extra_list);
>> +			}
>> +
>> +			temp = str + 1;
>> +		}
>> +		if (*str == 0)
>> +			break;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>>  static int blspec_init(void)
>>  {
>> +	dev_add_param_string(&global_device, "blspec.compatible.extra",
>> +			     blspec_extra_set, NULL, &blspec_extra_string, blspec_extra_list);
>>  	return bootentry_register_provider(blspec_bootentry_provider);
>>  }
>>  device_initcall(blspec_init);
>> +
>> +BAREBOX_MAGICVAR(global.blspec.compatible.extra, "Extra compatible to also match during bootloader entry matching");
> 

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