; --------------------------------------
; zasm: assemble "loader.z80"
; date: 2021-01-14 02:43:53
; --------------------------------------


;Retrieves CP/M from disk and loads it in memory starting at E400h
;Uses calls to ROM subroutine for disk read.
;Reads track 0, sectors 2 to 26, then track 1, sectors 1 to 25
;This program is loaded into LBA sector 0 of disk, read to loc. 0800h by ROM disk_read subroutine, and executed.

#target bin
#code _HOME, 0x1100

hstbuf    equ 0x1200         ;will put 256-byte raw sector here
disk_read equ 0x0296         ;subroutine in 2K ROM
cpm       equ 0xFA00         ;CP/M cold start entry in BIOS

main:
	ld c,1                   ;LBA bits 0 to 7
	ld b,0                   ;LBA bits 8 to 15
	ld e,0                   ;LBA bits 16 to 23
	ld hl,0xE400             ; Memory address -- start of CCP

loop:
	call disk_read           ;subroutine in ROM
	ld a,c
	cp 50
	jp z,done
	inc a
	ld c,a
	jp loop

done:
	out (1),a                ;switch memory config to all-RAM
	jp cpm                   ;to BIOS cold start entry


; +++ segments +++

#CODE _HOME    = $1100 =  4352,  size = $001C =    28

; +++ global symbols +++

_HOME      = $1100 =  4352  _HOME   loader.z80:6 (unused)
_HOME_end  = $111C =  4380  _HOME   loader.z80:6 (unused)
_HOME_size = $001C =    28  _HOME   loader.z80:6 (unused)
cpm        = $FA00 = 64000  _HOME   loader.z80:11
disk_read  = $0296 =   662  _HOME   loader.z80:10
done       = $1117 =  4375  _HOME   loader.z80:28
hstbuf     = $1200 =  4608  _HOME   loader.z80:9 (unused)
loop       = $1109 =  4361  _HOME   loader.z80:19
main       = $1100 =  4352  _HOME   loader.z80:13 (unused)


total time: 0.0002 sec.
no errors