Śāntideva's Bodhisattvacaryāvatāra is a renowned Mahayana text and the source of many ideas, prayers and practices, down to today, particularly the Bodhisattva ideal, Bodhicitta, and practices for achieving it.
Śāntideva wrote it in the 8th-century CE (with a miraculous story to go with it), and it was a major source of Atiśa's teachings in India and Tibet in the 11th-century CE. Atiśa learned about it from Dharmakīrtiśrī (Tibetan: Serlingpa), an Indonesian master, particularly the eighth chapter on practices for the development of Bodhicitta, according to commonly accepted history. Since then, it has become a standard part of the Mahayana literature across Asia and the world.
My question: are there any extant references to the Bodhisattvacaryāvatāra between those dates -- its origin in the 8th-century and Atiśa's 11th-centuries teachings -- commentaries or other mentions? The Indian Mahayana was at its peak in those years, prior to its decline in the wake of various invasions, so it stands to reason that the Bodhisattvacaryāvatāra would have been a significant part of it. Or did Serlingpa and Atiśa resurrect it from a relatively unknown, under-appreciated state?
Addendum 1/6/2021 -- The fact that Atiśa had to go to Indonesia for twelve years to study Bodhicitta and its practices with Serlingpa suggests that the subject was indeed under-appreciated in India prior to Atiśa, even at the great centers such as Nalanda and Vikramaśilā (where Atiśa was abbot upon return from Indonesia).
That all raises the question of ancient Mahayana history in Indonesia, which seems little studied or documented, at least in English.