collapseos/recipes/rc2014/zasm/glue.asm
Virgil Dupras ae028e3a86 blockdev: make implementors "random access"
This huge refactoring remove the Seek and Tell routine from blockdev
implementation requirements and change GetC and PutC's API so that they
take an address to read and write (through HL/DE) at each call.

The "PTR" approach in blockdev implementation was very redundant from
device to device and it made more sense to generalize. It's possible
that future device aren't "random access", but we'll be able to add more
device types later.

Another important change in this commit is that the "blockdev handle" is
now opaque. Previously, consumers of the API would happily call routines
directly from one of the 4 offsets. We can't do that any more. This
makes the API more solid for future improvements.

This change forced me to change a lot of things in fs, but overall,
things are now simpler. No more `FS_PTR`: the "device handle" now holds
the active pointer.

Lots, lots of changes, but it also feels a lot cleaner and solid.
2019-06-04 15:36:20 -04:00

120 lines
2.0 KiB
NASM

; classic RC2014 setup (8K ROM + 32K RAM) and a stock Serial I/O module
; The RAM module is selected on A15, so it has the range 0x8000-0xffff
.equ RAMSTART 0x8000
; kernel RAM usage is under 0x300 bytes. We give ourselves at least 0x300 bytes
; for the stack.
.equ RAMEND 0x8600
.equ PGM_CODEADDR RAMEND
.equ ACIA_CTL 0x80 ; Control and status. RS off.
.equ ACIA_IO 0x81 ; Transmit. RS on.
jp init ; 3 bytes
; *** Jump Table ***
jp strncmp
jp addDE
jp addHL
jp upcase
jp unsetZ
jp intoDE
jp intoHL
jp writeHLinDE
jp findchar
jp parseHex
jp parseHexPair
jp blkSel
jp fsFindFN
jp fsOpen
jp fsGetC
jp fsSeek
jp fsTell ; approaching 0x38...
; interrupt hook
.fill 0x38-$
jp aciaInt
; *** Jump Table (cont.) ***
jp cpHLDE
jp parseArgs
jp printstr
jp _blkGetC
jp _blkPutC
jp _blkSeek
jp _blkTell
#include "err.h"
#include "core.asm"
#include "parse.asm"
.equ ACIA_RAMSTART RAMSTART
#include "acia.asm"
.equ BLOCKDEV_RAMSTART ACIA_RAMEND
.equ BLOCKDEV_COUNT 3
#include "blockdev.asm"
; List of devices
.dw sdcGetC, sdcPutC
.dw mmapGetC, mmapPutC
.dw blk2GetC, blk2PutC
.equ MMAP_START 0xe000
#include "mmap.asm"
.equ STDIO_RAMSTART BLOCKDEV_RAMEND
#include "stdio.asm"
.equ FS_RAMSTART STDIO_RAMEND
.equ FS_HANDLE_COUNT 1
#include "fs.asm"
.equ SHELL_RAMSTART FS_RAMEND
.equ SHELL_EXTRA_CMD_COUNT 11
#include "shell.asm"
.dw sdcInitializeCmd, sdcFlushCmd
.dw blkBselCmd, blkSeekCmd, blkLoadCmd, blkSaveCmd
.dw fsOnCmd, flsCmd, fnewCmd, fdelCmd, fopnCmd
#include "fs_cmds.asm"
#include "blockdev_cmds.asm"
.equ PGM_RAMSTART SHELL_RAMEND
#include "pgm.asm"
.equ SDC_RAMSTART PGM_RAMEND
.equ SDC_PORT_CSHIGH 6
.equ SDC_PORT_CSLOW 5
.equ SDC_PORT_SPI 4
#include "sdc.asm"
.out SDC_RAMEND
init:
di
; setup stack
ld hl, RAMEND
ld sp, hl
im 1
call aciaInit
ld hl, aciaGetC
ld de, aciaPutC
call stdioInit
call shellInit
ld hl, pgmShellHook
ld (SHELL_CMDHOOK), hl
xor a
ld de, BLOCKDEV_SEL
call blkSel
ei
jp shellLoop
; *** blkdev 2: file handle 0 ***
blk2GetC:
ld ix, FS_HANDLES
jp fsGetC
blk2PutC:
ld ix, FS_HANDLES
jp fsPutC