A: The first contribution is divided into two steps:
1. first need to subscribe to it, addresses this https://lists.denx.de/listinfo/u-boot, the e-mail address corresponding to the name of a member, can send patches to uboot community, otherwise they will receive Post by non- member to a members-only list
2. After registration you can send patches, after sending to the https://patchwork.ozlabs.org/project/uboot/list/ see (if the first contribution after sending the patch need to wait at least 12 hours before will patches sent is displayed on the patchwork).