Dear baseband-developers team, Would you be so kind to advise me on the following: I desire (dramatically want very much) to learn / understand Osmocom projects. I am a beginner in programming and i try to understand / learn C files that the project is build of. As an example i tried to learn / understand for example an Osmocom message buffer — msgb.h file. But immediately faced some syntax difficulties: This is the extract of msgb.h file: struct msgb { struct llist_head list; /*!< \brief linked list header */ /* Part of which TRX logical channel we were received / transmitted */ /* FIXME: move them into the control buffer */ union { void *dst; /*!< \brief reference of origin/destination */ struct gsm_bts_trx *trx; }; As it can be seen a structure «msgb» has as one of its components another structure — «gsm_bts_trx» But in whole Osmocom BB project files i could not find definition / description of struct «gsm_bts_trx». Would you kindly advise me please how to see which components / constituents / elements are in this gsm_bts_trx structure? From which components is struct gsm_bts_trx build of? Thank you so much for your kind advise. -- Mario Lucas