f3c7ac9696
Instead of using the bootsector to load a bootloader, just put the bootloader in the ROM and call it a day. It looks for a file on the SD card in the root directory named `kernel.bin` and loads it into memory. This is not a perfect solution, as the kernel will grow larger and the kernel load address will have to change. At this point I could add back the bootloader, but that is for later. Also the bootloader is just a copy of the kernel, so that can be trimmed down a lot.
33 lines
309 B
ArmAsm
33 lines
309 B
ArmAsm
.include "io.inc65"
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.importzp sp, sreg
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.export _mapper_enable
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.export _mapper_read, _mapper_write
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.autoimport on
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.code
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; void mapper_enable(uint8_t en)
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_mapper_enable:
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sta MM_CTRL
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rts
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_mapper_read:
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phx
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tax
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lda MM_DATA,x
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ldx #$00
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rts
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_mapper_write:
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phx
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tax
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jsr popa
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sta MM_DATA,x
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plx
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rts
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