collapseos/blk/299

PC ORG @ 0x1e + ! ( chkPS )
( Note that you only need to call this in words that push
  back to PSP. If they don't, calling chkPS is redundant with
  check in next )
    EXX,
( We have the return address for this very call on the stack
  and protected registers. 2 - is to compensate that. )
    HL PS_ADDR 2 - LDddnn,
    SP SUBHLss,
    EXX,
    CNC RETcc,      ( PS_ADDR >= SP? good )
    JR, L2 BWR      ( abortUnderflow-B298 )
Copy boot.z80 to blkfs 2020-04-23 11:19:12 +10:00			`PC ORG @ 0x1e + ! ( chkPS )`
Optimize chkPS Use EXX instead of the stack for HL protection and remove all spurious uses of chkPS, I wanted to inline chkPS in next because of its "tight loop" status, but for reasons I don't understand, doing so breaks Collapse OS. Later... 2020-05-23 13:12:03 +10:00			`( Note that you only need to call this in words that push`
			`back to PSP. If they don't, calling chkPS is redundant with`
			`check in next )`
			`EXX,`
Copy boot.z80 to blkfs 2020-04-23 11:19:12 +10:00			`( We have the return address for this very call on the stack`
Optimize chkPS Use EXX instead of the stack for HL protection and remove all spurious uses of chkPS, I wanted to inline chkPS in next because of its "tight loop" status, but for reasons I don't understand, doing so breaks Collapse OS. Later... 2020-05-23 13:12:03 +10:00			`and protected registers. 2 - is to compensate that. )`
			`HL PS_ADDR 2 - LDddnn,`
Copy boot.z80 to blkfs 2020-04-23 11:19:12 +10:00			`SP SUBHLss,`
Optimize chkPS Use EXX instead of the stack for HL protection and remove all spurious uses of chkPS, I wanted to inline chkPS in next because of its "tight loop" status, but for reasons I don't understand, doing so breaks Collapse OS. Later... 2020-05-23 13:12:03 +10:00			`EXX,`
Replace INITIAL_SP with PS_ADDR conf Now I struggle to remember why I ever did things they way I did. There must have been a reason... 2020-05-12 11:08:24 +10:00			`CNC RETcc, ( PS_ADDR >= SP? good )`
Copy boot.z80 to blkfs 2020-04-23 11:19:12 +10:00			`JR, L2 BWR ( abortUnderflow-B298 )`