All that; usu with limiting force: the only thing that.
1887 Scribner’s Mag. 2.479 AR, Cap’n Bulah sets much store by thet ar baby, iz you kin by your’n; an’ mo’, too, ’kase it’s all’s she got. 1898 Harper’s New Mth. Mag. 97.554 seNY, All’s I know is I made a ’nation fool of myself a-drivin’ her out’n the house like I done. 1902 Atlantic Mth. 90.701 ME, Wal, father he was stannin’ there for’rard listenin’ away for allst he was wuth. 1949 WELS Suppl. WI, Alls [ɔls]. “Alls he wanted to do. . .” Young adult, college student, June 20, 1949. 1967 DARE FW Addit cwMA, All’s [ɔlz] I get is . . , all’s he can do is. . . Heard used by 3 or 4 natives of Amherst in their middle or late twenties. All use it fairly frequently. 1975 Gould ME Lingo 35, Alst—Perhaps allst. It means all or “everything that.” “Alst I know is what they tell me.” “Alst you do to fix that leak is buy a new bilge pump.” c1979 in 1988 Lawless God’s Peculiar 13 sIN, Alst he’d do was sit in front of the back door and whine. 2001 DARE File, Alls I want to do is leave. . . It is widespread in the US, not at all restricted to Central Texas. I have heard it in South Midland . . , North Midland, and Inland Northern varieties. 2013 Lamb We Are Water 307 CT, Because I’m left-handed and all’s you had was right-handed scissors. 2016 in 2017 DARE File—Internet wNC, We use all’s in place of all that: “All’s I know is I did what she told me to do. And if that ain’t good enough then I don’t know what else a body could do.” The grammar usages above are all very common in my area of Appalachia—and in my household.