From 95311ab84fb8ea6a5509aaa909be825c74e691ca Mon Sep 17 00:00:00 2001
From: cheapie <cheapiephp@gmail.com>
Date: Sat, 6 Jun 2026 12:42:38 -0500
Subject: Add (experimental for now) mesecons I/O support

---
 assembly/meseconsio/Makefile        |  24 ++++++++++++++++++++++++
 assembly/meseconsio/meseconsio.S    |  30 ++++++++++++++++++++++++++++++
 assembly/meseconsio/meseconsio.elf  | Bin 0 -> 5348 bytes
 assembly/meseconsio/meseconsio.hex  |   7 +++++++
 assembly/meseconsio/meseconsio.o    | Bin 0 -> 1192 bytes
 assembly/meseconsio/rvcontroller.ld |   1 +
 6 files changed, 62 insertions(+)
 create mode 100644 assembly/meseconsio/Makefile
 create mode 100644 assembly/meseconsio/meseconsio.S
 create mode 100755 assembly/meseconsio/meseconsio.elf
 create mode 100644 assembly/meseconsio/meseconsio.hex
 create mode 100644 assembly/meseconsio/meseconsio.o
 create mode 120000 assembly/meseconsio/rvcontroller.ld

(limited to 'assembly')

diff --git a/assembly/meseconsio/Makefile b/assembly/meseconsio/Makefile
new file mode 100644
index 0000000..786418a
--- /dev/null
+++ b/assembly/meseconsio/Makefile
@@ -0,0 +1,24 @@
+MARCH ?= rv32imacbzicntr_zicond_zicsr_zifencei_zihintpause_zilsd_zclsd_zabha_zacas_zawrs_zbkb_zbkx_zcb_zcmp_zcmt
+
+.PHONY: all dump load clean
+
+all: meseconsio.hex
+
+meseconsio.o: meseconsio.S
+	riscv32-none-elf-as -I../rvcontroller-libraries -march=${MARCH} -o meseconsio.o meseconsio.S
+
+meseconsio.elf:  meseconsio.o
+	riscv32-none-elf-ld -T rvcontroller.ld --no-warn-rwx-segments -o meseconsio.elf meseconsio.o
+
+dump: meseconsio.elf
+	riscv32-none-elf-objdump -d meseconsio.elf
+
+meseconsio.hex: meseconsio.elf
+	riscv32-none-elf-objcopy -O ihex meseconsio.elf meseconsio.hex
+
+load: meseconsio.hex
+	bash -c "wl-copy < meseconsio.hex"
+
+clean:
+	rm -f meseconsio.bin meseconsio.elf meseconsio.o
+
diff --git a/assembly/meseconsio/meseconsio.S b/assembly/meseconsio/meseconsio.S
new file mode 100644
index 0000000..f2a441f
--- /dev/null
+++ b/assembly/meseconsio/meseconsio.S
@@ -0,0 +1,30 @@
+              li s0,0xffff0000
+              csrw 0x801,s0            # Set MMIO base address
+
+              li t0,0x7                # Pin D input, others output
+              sb t0,0(s0)              # Write to mesecons I/O direction register
+
+start:        lr.w x0,0(s0)            # Establish a reservation set on the mesecons I/O region
+              wrs.nto                  # Wait for it to become invalid
+              lb t0,1(s0)              # Read the mesecons I/O data
+              andi t1,t0,0x8           # Is pin D on?
+              beqz t1,start            # If not, go wait again
+
+              li t0,1                  # only A on
+              sb t0,1(s0)
+              pause
+              pause
+              pause
+              li t0,2                  # only B on
+              sb t0,1(s0)
+              pause
+              pause
+              pause
+              li t0,4                  # only C on
+              sb t0,1(s0)
+              pause
+              pause
+              pause
+              li t0,0                  # all off
+              sb t0,1(s0)
+              j start
diff --git a/assembly/meseconsio/meseconsio.elf b/assembly/meseconsio/meseconsio.elf
new file mode 100755
index 0000000..09468fe
Binary files /dev/null and b/assembly/meseconsio/meseconsio.elf differ
diff --git a/assembly/meseconsio/meseconsio.hex b/assembly/meseconsio/meseconsio.hex
new file mode 100644
index 0000000..5feb581
--- /dev/null
+++ b/assembly/meseconsio/meseconsio.hex
@@ -0,0 +1,7 @@
+:100000004174731014809D42230054002F2004106B
+:100010007300D0008302140013F38200E30803FE90
+:100020008542A30054000F0000010F0000010F00E3
+:1000300000018942A30054000F0000010F000001DD
+:100040000F0000019142A30054000F0000010F00B7
+:0E00500000010F0000018142A300540045BFD3
+:00000001FF
diff --git a/assembly/meseconsio/meseconsio.o b/assembly/meseconsio/meseconsio.o
new file mode 100644
index 0000000..33ce2df
Binary files /dev/null and b/assembly/meseconsio/meseconsio.o differ
diff --git a/assembly/meseconsio/rvcontroller.ld b/assembly/meseconsio/rvcontroller.ld
new file mode 120000
index 0000000..bc01402
--- /dev/null
+++ b/assembly/meseconsio/rvcontroller.ld
@@ -0,0 +1 @@
+../../rvcontroller.ld
\ No newline at end of file
-- 
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