mirror of
https://github.com/LNH-team/pico-loader.git
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68 lines
1.3 KiB
ArmAsm
68 lines
1.3 KiB
ArmAsm
.cpu arm7tdmi
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.syntax unified
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.section "akrpg_sdreadsector", "ax"
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.thumb
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// r0 = src sector
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// r1 = dst
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// r2 = sector count
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.global akrpg_sdReadSector
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.type akrpg_sdReadSector, %function
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akrpg_sdReadSector:
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push {r4-r5,lr}
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ldr r4, =0x040001A0
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ldr r5, =0x04100010
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sector_loop:
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// NOW we can start reading things
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movs r3, #0xB7
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str r3, [r4,#0x8]
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// The full CMD is B7 00 00 00 00 13 00 00
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// If we use 0x1300 and str, then it goes into the expected place
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movs r3, #0x13
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lsls r3, r3, #8
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str r3, [r4,#0xC]
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ldr r3, =0xA1406004
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str r3, [r4,#4]
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akrpg_sdReadSector_read_loop:
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ldrb r3, [r4,#6]
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lsrs r3, r3, #8 // check if data is ready
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bcc akrpg_sdReadSector_read_loop_check_transfer_end // if not skip reading
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ldr r3, [r5]
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stmia r1!, {r3}
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akrpg_sdReadSector_read_loop_check_transfer_end:
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ldrb r3, [r4,#7]
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lsrs r3, r3, #8 // check if transfer is done
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bcs akrpg_sdReadSector_read_loop
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// Wait for SD state
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push {r0-r1}
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movs r0, #0
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movs r1, #7
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ldr r3, akrpg_sdReadSector_sdWaitForState_address
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bl blx_r3
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pop {r0-r1}
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subs r2, #1
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bne sector_loop
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pop {r4-r5,pc}
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blx_r3:
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bx r3
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.balign 4
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.global akrpg_sdReadSector_sdWaitForState_address
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akrpg_sdReadSector_sdWaitForState_address:
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.word 0
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.pool
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.end
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