mirror of
https://github.com/LNH-team/pico-loader.git
synced 2026-06-02 09:16:49 +02:00
6a97b677a7
- Supercard CF (SUPERCARDCF) - GBA Media Player CF (MPCF) - M3 Adapter CF (M3CF) - Max Media Dock CF (MMCF)
78 lines
1.7 KiB
ArmAsm
78 lines
1.7 KiB
ArmAsm
.cpu arm7tdmi
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.syntax unified
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.thumb
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.section "cf_wait_functions", "ax"
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.equ CF_STS_DRQ, 0x08
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.equ CF_STS_DSC, 0x10
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.equ CF_STS_READY, 0x40
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.equ CF_STS_INSERTED, 0x50
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.equ CF_STS_BUSY, 0x80
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.equ CF_CARD_TIMEOUT, 10000000
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@ Waits until the card is ready to receive commands
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@ this function doesn't alter r0, but sets the zero flag on failure and clears it on success
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@ bool cf_waitCardAvailableForCommands()
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.global cf_waitCardAvailableForCommands
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.type cf_waitCardAvailableForCommands, %function
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cf_waitCardAvailableForCommands:
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push {r0-r4, lr}
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@ wait for card to finish previous commands
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ldr r1, =CF_CARD_TIMEOUT
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ldr r2, cf_waitFunctions_reg_cmd
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movs r4, r1
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still_busy:
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ldrh r0, [r2]
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@ r0 & CF_STS_BUSY == 0
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lsls r0, #25
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bcc no_longer_busy
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subs r1, #1
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bne still_busy
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no_longer_busy:
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@ wait for card to be ready for commands
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movs r3, (CF_STS_READY | CF_STS_DSC)
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1:
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ldrh r1, [r2]
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tst r1, r3
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@ timeout expired
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bne ready
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subs r4, #1
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@ not ready
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bne 1b
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@ timeout expired, return 0
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pop {r0-r4, pc}
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@ Waits until the card is ready to write/return the next block
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@ this function doesn't alter r0, but sets the zero flag on failure and clears it on success
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@ bool cf_waitNextBlockReady()
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.global cf_waitNextBlockReady
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.type cf_waitNextBlockReady, %function
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cf_waitNextBlockReady:
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push {r0-r4, lr}
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ldr r0, =CF_CARD_TIMEOUT
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ldr r1, cf_waitFunctions_reg_cmd
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1:
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ldrb r2, [r1]
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cmp r2, (CF_STS_READY | CF_STS_DSC | CF_STS_DRQ)
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@ timeout expired
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beq ready
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subs r0, #1
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@ not ready
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bne 1b
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@ timeout expired, return 0
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pop {r0-r4, pc}
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ready:
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movs r0, #1
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pop {r0-r4, pc}
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.balign 4
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.global cf_waitFunctions_reg_cmd
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cf_waitFunctions_reg_cmd:
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.word 0
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