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419eb700b5
The way we want to use the INITBSS segment - and especially the fact that it won't have the type bss on all ROM based targets - means that the name INITBSS is misleading. After all INIT is the best name from my perspective as it serves several purposes and therefore needs a rather generic name. Unfortunately this means that the current INIT segment needs to be renamed too. Looking for a short (ideally 4 letter) name I came up with ONCE as it contains all code (and data) accessed only once during initialization.
31 lines
918 B
ArmAsm
31 lines
918 B
ArmAsm
.include "pce.inc"
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.export psg_init
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.segment "ONCE"
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psg_init:
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clx
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stz PSG_GLOBAL_PAN ; Clear global balance
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psg_clear_loop:
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stx PSG_CHAN_SELECT ; Select channel
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stz PSG_FREQ_LO ; Clear frequency LSB
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stz PSG_FREQ_HI ; Clear frequency MSB
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stz PSG_CHAN_CTRL ; Clear volume
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stz PSG_CHAN_PAN ; Clear balance
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stz PSG_NOISE ; Clear noise control
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stz PSG_LFO_FREQ ; Clear LFO frequency
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stz PSG_LFO_CTRL ; Clear LFO control
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cly
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psg_clear_waveform:
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stz PSG_CHAN_DATA ; Clear waveform byte
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iny
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cpy #$20
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bne psg_clear_waveform
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inx
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cpx #$06
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bne psg_clear_loop
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rts
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