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#include "custom_ops.S"
.text
.global _start
_start:
li a0, 0x00300000 # HOST_CTRL_BASE
li a1, 1 << 1 | 1 << 0 # ARINT | AWINT
li a2, 1 << 0 # B.VALID = 1
li a3, 0x8 # Firmware handover word
la a4, .read_data
li a5, 1 << 11 | 1 << 9 # CTRL.WVALID | CTRL.AWVALID
li a6, 1 << 12 # CTRL.BDONE, doesn't fit in andi
sw a1, 0(a0)
.wait_axi:
picorv32_waitirq_insn(zero)
lw t0, 0(a0)
andi t1, t0, 1 << 8 # ARVALID
bne t1, zero, .read
and t0, t0, a5
beq t0, a5, .write
j .wait_axi
.read:
lw t0, 4(a0)
andi t1, t0, 1 << 0 # AW.VALID
beq t1, zero, .wait_axi
andi t0, t0, 0b11 << 2
add t0, a4, t0
lw t0, 0(t0)
sw t0, 12(a0) # R.DATA
.read_done:
lw t0, 0(a0)
andi t0, t0, 1 << 10 # CTRL.RDONE
beq t0, zero, .read_done
j .wait_axi
.write:
lw t0, 8(a0)
andi t1, t0, 1 << 0 # AW.VALID
beq t1, zero, .wait_axi
lw t1, 16(a0)
sw a2, 20(a0)
.write_done:
lw t2, 0(a0)
and t2, t2, a6
beq t2, zero, .write_done
andi t0, t0, 0b111100 # Entendemos words 0-15
bne t0, a3, .wait_axi
sw zero, 0(a0)
# Pass magic & hardware version
lw a0, 0(a4)
lw a1, 4(a4)
jalr t1
j .
.balign 4
.read_data:
# Magic
.word 0x4a7a7b0c
# Hardware major.minor.patch
.word 1 << 16 | 0 << 8 | 0 << 0
# Firmware yyyy.mm.dd.build
.word 2024 << 19 | 5 << 15 | 12 << 10 | 1 << 0
# Register map version, rev 0 means this is the bootrom firmware
.word 0
.balign 4
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