Derivation of a slang greeting in Yorkshire: "Aye up serry"

Solution 1:

According to The Voice of England's Past New York Times 8 July 1984 by Paul West of Derbyshire, England:

"Eigh-up, serry," they call out to you, as to one another, meaning: I have noticed you, sirrah (an Elizabethan word).

I, Said the Sparrow (1963), also by Paul West, is the oldest mention of the phrase that I found and says:

[page 82] 'Thee' and 'thou' are common forms of address; you always address a male interlocutor as 'serry' (which really brought to life for me the Elizabethan 'sirrah')

and

[page 87] He must have been one of the few literary editors who knew what the local greeting, 'Eigh-up, serry', meant.

Also, according to the 1920 Dialect of the Staffordshire Moorlands Transactions and Annual Report of the Staffordshire Field Club, volume LIV, pages 44-53,

The farm lad is still sirrah (pronounced surrey)

...

The common greeting among the young farm-hands (male) is “ How go, sirrah ? ” This, of course, is common enough in Shakespeare's time, cf. Ah, sirrah ” (As You Like It, iv, 3), and “ Sirrah begone ” (Marlowe, Edward II, v, 2).