From b9f1829b68530dbcabfec66835aea136d385e50e Mon Sep 17 00:00:00 2001 From: Alejandro Soto Date: Sun, 12 May 2024 13:25:45 -0600 Subject: rtl/gfx/firmware: implement bootloader --- rtl/gfx/firmware/gfx_bootrom.S | 76 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 76 insertions(+) create mode 100644 rtl/gfx/firmware/gfx_bootrom.S (limited to 'rtl/gfx/firmware/gfx_bootrom.S') diff --git a/rtl/gfx/firmware/gfx_bootrom.S b/rtl/gfx/firmware/gfx_bootrom.S new file mode 100644 index 0000000..bf7bd7d --- /dev/null +++ b/rtl/gfx/firmware/gfx_bootrom.S @@ -0,0 +1,76 @@ +#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, ~0b11 + 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 << 18 | 5 << 15 | 12 << 10 | 1 << 0 + # Register map version, rev 0 means this is the bootrom firmware + .word 0 + +.balign 4 -- cgit v1.2.3