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uxn/projects/examples/old/asma-piano.tal
2022-03-14 10:21:36 -07:00

102 lines
2.9 KiB
Tal

( devices )
|00 @System [ &vector $2 &wst $1 &rst $1 &pad $4 &r $2 &g $2 &b $2 &debug $1 &halt $1 ]
|10 @Console [ &vector $2 &read $1 &pad $5 &write $1 &error $1 ]
|a0 @File [ &vector $2 &success $2 &stat $2 &delete $1 &append $1 &name $2 &length $2 &read $2 &write $2 ]
( vectors )
|0100 @reset
(
Set the log level for helping to debug stuff.
Its value is the bitwise OR of all the following output types:
#01 prints the number of lines in the source code,
#04 dumps all defined labels at end, and
#08 prints the heap usage.
)
#0d ;asma/log-level STA
;asma-heap ;heap STA2
(
Assemble the source code into an output ROM file.
If all you want is to use asma.tal to assemble files, insert a BRK
after this statement.
)
;&source-file ;&dest-file ;asma-assemble-file JSR2
(
If an error has occurred, BRK here, otherwise continue. (The error
message will already have been printed to the Console in
asma-assemble-file.)
)
;asma/error LDA2 #0000 EQU2 JMP BRK
(
Load the output ROM over the currently running program, almost as if
we loaded the ROM with uxnemu directly!
It's not a totally pristine environment, as File/read doesn't zero out
memory beyond the end of the file. So if the assembled program assumes
that all memory above it is zero, it may misbehave.
Asma itself doesn't use the zero page, but this example code writes a
DEO2 instruction to 0x00ff. In order to execute File/read and have the
CPU continue at memory location 0x0100, we write the final DEO2
instruction there and jump there as our final act.
Just in case the assembled code is zero-length (which can occur when
assembling an empty source file), we write a BRK to the reset vector so
that will prevent an infinite loop.
)
;&dest-file .File/name DEO2
#ff00 .File/length DEO2
#0100 .File/read
LIT DEO2 #00ff STA
LIT BRK #0100 STA
#00ff JMP2
&source-file
"projects/examples/demos/piano.tal 00
&dest-file
"bin/asma-boot.rom 00
~projects/library/asma.tal
(
Heap, a large temporary area for keeping track of labels. More complex
programs need more of this space. If there's insufficient space then the
assembly process will fail, but having extra space above what the most
complex program needs provides no benefit.
This heap, and the buffers below, are free to be used to hold temporary
data between assembly runs, and do not need to be initialized with any
particular contents to use the assembler.
)
@asma-heap
|e000 &end
(
Buffer for use with loading source code.
The minimum size is the length of the longest token plus one, which is
0x21 to keep the same capability of the C assembler.
Larger sizes are more efficient, provided there is enough
heap space to keep track of all the labels.
)
@asma-read-buffer
|f800 &end
(
Buffer for use with writing output.
The minimum size is 1, and larger sizes are more efficient.
)
@asma-write-buffer
|ffff &end