Hosea used the words "the covenant" in combination with "Adam".

But like Adam they transgressed the covenant;
there they dealt faithlessly with Me.

-- Hosea 6:7 (ESV)

Some belief that this mean God made a covenant with Adam, however:

• there are no other scripture in the Bible that mentions this covenant;
• in those days, it was only Adam and God: therefore, the concept making covenants, because of trust issues, most likely did not exist yet;
• It would be unfair of God to condemn Israel for something that Adam did.
• It would also seem unnatural for Hosea to be concerned about Israel breaking a covenant made specifically to Israel (Hosea 8:1-3) and then unexpectedly confuse it with another covenant nobody knows about.
• Hosea wrote refer to "Adam" as "they" and "there" and in the same scripture condemn other regions too like Ephriam, Judah (Hosea 6:4,10-11), Gilead (Hosea 6:8), Shechem (Hosea 6:9) and Samaria (Hosea 7:1). This lead some scholars to belief that "Adam" might have been a known region in his days.
• Other scholars reason that because Hosea was only doing a comparison and meant, "like Adam" was disobedient, "they" were also disobedient by breaking their covenant.

In Genesis is written:

The LORD God took the man and put him in the garden of Eden to work it and keep it.

And the LORD God commanded the man, saying, “You may surely eat of every tree of the garden, but of the tree of the knowledge of good and evil you shall not eat, for in the day that you eat of it you shall surely die.”

-- Genesis 2:15-17 (ESV)

Scripture does not mention any signs to remind Adam of the "covenant", nor was there any kind of negotiation recorded like a request from Adam's side what he expects from God in return. It was simply God that commanded Adam.

Even when Adam was disobedient, God said to Adam:

“Because you have listened to the voice of your wife and have eaten of the tree of which I commanded you, ‘You shall not eat of it,’... -- Genesis 3:17