annotate src/boot/boot.s @ 2:58ebd84822e7
it works
| author |
John Tsiombikas <nuclear@member.fsf.org> |
| date |
Thu, 22 Feb 2018 12:44:20 +0200 |
| parents |
48093e4bd99a |
| children |
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| rev |
line source |
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nuclear@0
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1 | vi:filetype=gas68k:
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nuclear@0
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2 .equ CMD_READ, 2
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nuclear@2
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3 .equ EXEC_DO_IO, -0x1c8
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nuclear@2
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4 .equ LOADADDR, 0x10000
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nuclear@0
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5
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nuclear@2
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6 start:
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nuclear@0
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7 | starting with trackdisk device I/O request pointer in a1
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nuclear@1
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8 | load the program at 0x100 and jump there
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nuclear@1
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9 | program length is patched by mk_adf just before start
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nuclear@2
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10 move.l -6(%pc), %d0 | get program size
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nuclear@2
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11 move.w #0x080, 0xdff180
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nuclear@1
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12 move.l %d0, 0x24(%a1) | I/O length
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nuclear@2
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13 move.l #LOADADDR, 0x28(%a1) | I/O data pointer
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nuclear@0
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14 move.l #512, 0x2c(%a1) | I/O offset (skip first sector)
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nuclear@0
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15 move.w #CMD_READ, 0x1c(%a1) | I/O command
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nuclear@0
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16 jsr EXEC_DO_IO(%a6)
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nuclear@2
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17 move.w #0xf0f, 0xdff180
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nuclear@0
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18
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nuclear@2
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19 jmp LOADADDR
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nuclear@0
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20 .align 4
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