Winter
Here's my take on semi-solids / solids for 6 months old.
They can take canned cereal or rice (brown or white) powder.
You can also cook porridge. But porridge should be very fine (like chok), not grain porridge (like teochew muay). Baby may not know how to chew yet. To get chok, u can cook porridge overnight in slow cooker, or process rice grains into smaller pieces using blender or chopper before cooking. Some rice cookers have porridge function that can cook very fine porridge. When u add fish or vege etc, they must also be blended till fine. Either blend before cooking, or mash well before feeding.
You will find that every person has a different take on weaning , it will drive u nuts LOL Most imptly, see what your boy is ready for. No hard and fast rule.
Anyway if you want to gradually increase solids to 2-3 times a day as bb grows older, some flexibility and variety will be good. E.g. oatmeal cereal in morning, porridge in afternoon.
Btw if u are starting solids for first time at 6 months, maybe start with single grain cereal e.g. healthy times brown rice cereal or brown rice powder. then slowly work your way to more complicated stuff like cooking ur own porridge with ingredients, or mixed grain cereal.