sdc.s: Fix merge problem

diff --git a/Kernel/platform-coco2cart/sdc.s b/Kernel/platform-coco2cart/sdc.s
index e69de29..3d0eaa1 100644 (file)
--- a/Kernel/platform-coco2cart/sdc.s
+++ b/Kernel/platform-coco2cart/sdc.s
@@ -0,0 +1,77 @@
+;;;
+;;;  The CoCoSDC Driver
+;;;    Big thanks for Darren Atkinson for good documentation
+;;;    and help with autodetection in the init method
+;;;
+;;; 
+
+;;; exported
+       .globl _sdc_read_data
+       .globl _sdc_write_data
+       .globl _sdcpage
+
+
+*********************************************************************
+***    Hardware Addressing
+*********************************************************************
+CTRLATCH    equ    $FF40          ; controller latch (write)
+CMDREG      equ    $FF48          ; command register (write)
+STATREG     equ    $FF48          ; status register (read)
+PREG1       equ    $FF49          ; param register 1
+PREG2       equ    $FF4A          ; param register 2
+PREG3       equ    $FF4B          ; param register 3
+DATREGA     equ    PREG2          ; first data register
+DATREGB     equ    PREG3          ; second data register
+
+
+
+       section .common
+
+_sdcpage .db 0
+
+       
+;;; TODO: collasp sdc read/write with self modding code.
+
+;;; Write 256 bytes from SDC
+;;;   takes: sdcpage = rawfalg, X = data address
+;;;   returns: nothing
+_sdc_write_data
+       pshs    y,u
+       ldy     #PREG2          ; set Y to point at data reg a
+       ldd     #64*256+4       ; A = chunk count (64), B = bytes per chunk (4)
+       tst     _sdcpage        ; test user/kernel xfer
+       beq     wrChnk          ; if zero then stay in kernel space
+       jsr     map_process_always ; else flip in user space
+wrChnk  ldu            ,x              ; get 2 data bytes from source
+       stu     ,y              ; send data to controller
+       ldu     2,x             ; two more bytes..
+       stu     ,y              ; ..for this chunk
+       abx                     ; increment X by chunk size (4)
+       deca                    ; decrement loop counter
+       bne     wrChnk          ; loop until all chunks written
+       jsr     map_kernel      ; reset to kernel space
+       puls    y,u,pc          ; return
+
+;;; Reads 256 bytes from SDC
+;;;   takes: sdcpage = rawflag, X = data address
+;;;   returns: nothing
+_sdc_read_data
+       pshs    y,u
+       ldy     #PREG2          ; set Y to point to data reg a
+       ldd     #32*256+8       ; A = chunk count (32), B = bytes per chunk (8)
+       tst     _sdcpage        ; test usr/kernel xfer
+       beq     rdChnk          ; if zero then stay in kernel space
+       jsr     map_process_always ; else flip to user space
+rdChnk         ldu     ,y              ; read 1st pair of bytes for the chunk
+       stu     ,x              ; store to buffer
+       ldu     ,y              ; bytes 3 and 4 of..
+       stu     2,x             ; ..the chunk
+       ldu     ,y              ; bytes 5 and 6 of..
+       stu     4,x             ; ..the chunk
+       ldu     ,y              ; bytes 7 and 8 of..
+       stu     6,x             ; ..the chunk
+       abx                     ; increment X by chunk size (8)
+       deca                    ; decrement loop counter
+       bne     rdChnk          ; loop if more chunks to read
+       jsr     map_kernel      ; reset to kernel space
+       puls    y,u,pc          ; return