Not Implemented: save/load RISC-V 16bit programs in EEPROM

.vscode/settings.json

@@ -30,6 +30,9 @@
         "riscv-disas.h": "c",
         "ch32v003_i2c.h": "c",
         "i2c_tx.h": "c",
-        "oled_min.h": "c"
+        "oled_min.h": "c",
+        "array": "c",
+        "string": "c",
+        "string_view": "c"
     },
 }

save-rvasm/Makefile

@@ -0,0 +1,13 @@
+TARGET:=save-rvasm
+ADDITIONAL_C_FILES:= rv.c
+include ../ch32v003fun/ch32v003fun.mk
+clean:
+	rm -f $(TARGET).elf $(TARGET).hex $(TARGET).bin $(TARGET).map $(TARGET).lst \
+		$(TARGET).o $(TARGET).d $(TARGET).srec $(TARGET).sym $(TARGET).lss
+	$(MAKE) -f Makefile-emulator clean
+
+emulator:
+	$(MAKE) -f Makefile-emulator clean
+	$(MAKE) -f Makefile-emulator 
+
+.PHONY: clean emulator

save-rvasm/Makefile-emulator

@@ -0,0 +1,35 @@
+CC=gcc
+INCLUDES=-I../emulator -I../data -I.
+CFLAGS=-g -Wall -Wextra -Wshadow -Wswitch -Wfloat-equal $(INCLUDES)
+LDFLAGS=$(CFLAGS)
+
+UNAME_S := $(shell uname -s)
+ifeq ($(UNAME_S), Darwin)
+    LDFLAGS += -framework CoreFoundation -framework ApplicationServices -pthread
+endif
+
+SRCS=save-rvasm.c rv.c
+TARGET=save-rvasm
+
+SRCS += $(wildcard ../emulator/*.c)
+ifneq ($(UNAME_S), Darwin)
+SRCS := $(filter-out ../emulator/system_mac.c,$(SRCS))
+endif
+OBJS = $(SRCS:.c=.o)
+# Default target
+all: $(TARGET)
+
+# Linking
+$(TARGET): $(OBJS)
+	$(CC) $(OBJS) $(LDFLAGS) -o $(TARGET)
+
+# Compiling
+%.o: %.c
+	$(CC) $(CFLAGS) -c $< -o $@
+
+# Clean up
+clean:
+	rm -f $(OBJS) $(TARGET) *.exe
+
+# Phony targets
+.PHONY: all clean

save-rvasm/RV-LICENSE.txt

@@ -0,0 +1,18 @@
+Copyright (c) 2023-2024 Max Nurzia
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the “Software”), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

save-rvasm/RV-README.md

@@ -0,0 +1,128 @@
+# rv
+
+RISC-V CPU core written in ANSI C.
+
+Features:
+
+- `RV32IMAC_Zicsr` implementation with M-mode and S-mode
+- Boots RISCV32 Linux
+- Passes all supported tests in [`riscv-tests`](https://github.com/riscv/riscv-tests)
+- ~800 lines of code
+- Doesn't use any integer types larger than 32 bits, even for multiplication
+- Simple API (two required functions, plus one memory callback function that you provide)
+- No memory allocations
+
+## API
+
+```c
+/* Memory access callback: data is input/output, return RV_BAD on fault. */
+typedef rv_res (*rv_bus_cb)(void *user, rv_u32 addr, rv_u8 *data, rv_u32 is_store, rv_u32 width);
+
+/* Initialize CPU. You can call this again on `cpu` to reset it. */
+void rv_init(rv *cpu, void *user, rv_bus_cb bus_cb);
+
+/* Single-step CPU. Returns RV_E* on exception. */
+rv_u32 rv_step(rv *cpu);
+```
+
+## Usage
+
+```c
+#include <stdio.h>
+#include <string.h>
+
+#include "rv.h"
+
+#define RAM_BASE 0x80000000
+#define RAM_SIZE 0x10000
+
+rv_res bus_cb(void *user, rv_u32 addr, rv_u8 *data, rv_u32 is_store,
+              rv_u32 width) {
+  rv_u8 *mem = (rv_u8 *)user + addr - RAM_BASE;
+  if (addr < RAM_BASE || addr + width >= RAM_BASE + RAM_SIZE)
+    return RV_BAD;
+  memcpy(is_store ? mem : data, is_store ? data : mem, width);
+  return RV_OK;
+}
+
+rv_u32 program[2] = {
+    /*            */             /* _start: */
+    /* 0x80000000 */ 0x02A88893, /* add a7, a7, 42 */
+    /* 0x80000004 */ 0x00000073  /* ecall */
+};
+
+int main(void) {
+  rv_u8 mem[RAM_SIZE];
+  rv cpu;
+  rv_init(&cpu, (void *)mem, &bus_cb);
+  memcpy((void *)mem, (void *)program, sizeof(program));
+  while (rv_step(&cpu) != RV_EMECALL) {
+  }
+  printf("Environment call @ %08X: %u\n", cpu.csr.mepc, cpu.r[17]);
+  return 0;
+}
+```
+
+See [`tools/example/example.c`](tools/example/example.c).
+
+## Running Linux
+
+This repository contains a machine emulator that can use `rv` to boot Linux.
+See [`tools/linux/README.md`](tools/linux/README.md).
+
+## Targeting `rv`
+
+Use [riscv-gnu-toolchain](https://github.com/riscv-collab/riscv-gnu-toolchain) with [tools/link.ld](tools/link.ld).
+
+Suggested GCC commandline:
+
+`riscv64-unknown-elf-gcc example.S -nostdlib -nostartfiles -Tlink.ld -march=rv32imac -mabi=ilp32 -o example.o -e _start -g -no-pie`
+
+To dump a binary starting at `0x80000000` that can be directly loaded by `rv` as in the above example:
+
+`riscv64-unknown-elf-objcopy -g -O binary example.o example.bin`
+
+## Instruction List
+
+Click an instruction to see its implementation in `rv.c`.
+
+- [`add`](rv.c#L589)[`addi`](rv.c#L589)[`amoadd.w`](rv.c#L548)[`amoand.w`](rv.c#L560)[`amomax.w`](rv.c#L564)[`amomaxu.w`](rv.c#L568)[`amomin.w`](rv.c#L562)[`amominu.w`](rv.c#L566)
+- [`amoor.w`](rv.c#L558)[`amoswap.w`](rv.c#L550)[`amoxor.w`](rv.c#L556)[`and`](rv.c#L606)[`andi`](rv.c#L606)[`auipc`](rv.c#L696)[`beq`](rv.c#L509)[`bge`](rv.c#L512)
+- [`bgtu`](rv.c#L514)[`blt`](rv.c#L511)[`bltu`](rv.c#L513)[`bne`](rv.c#L510)[`c.add`](rv.c#L386)[`c.addi`](rv.c#L324)[`c.addi16sp`](rv.c#L331)[`c.and`](rv.c#L352)
+- [`c.andi`](rv.c#L343)[`c.beqz`](rv.c#L362)[`c.bnez`](rv.c#L364)[`c.ebreak`](rv.c#L383)[`c.j`](rv.c#L360)[`c.jal`](rv.c#L326)[`c.jalr`](rv.c#L380)[`c.jr`](rv.c#L375)
+- [`c.li`](rv.c#L328)[`c.lui`](rv.c#L333)[`c.lw`](rv.c#L316)[`c.lwsp`](rv.c#L372)[`c.mv`](rv.c#L377)[`c.or`](rv.c#L350)[`c.slli`](rv.c#L370)[`c.srai`](rv.c#L341)
+- [`c.srli`](rv.c#L339)[`c.sub`](rv.c#L346)[`c.sw`](rv.c#L318)[`c.swsp`](rv.c#L388)[`c.xor`](rv.c#L348)[`csrrc`](rv.c#L649)[`csrrci`](rv.c#L649)[`csrrs`](rv.c#L643)
+- [`csrrsi`](rv.c#L643)[`csrrw`](rv.c#L634)[`csrrwi`](rv.c#L634)[`div`](rv.c#L620)[`divu`](rv.c#L622)[`ebreak`](rv.c#L685)[`ecall`](rv.c#L682)[`fence`](rv.c#L531)
+- [`fence.i`](rv.c#L535)[`jal`](rv.c#L577)[`jalr`](rv.c#L524)[`lb`](rv.c#L488)[`lbu`](rv.c#L488)[`lh`](rv.c#L488)[`lhu`](rv.c#L488)[`lr.w`](rv.c#L552)
+- [`lui`](rv.c#L698)[`lw`](rv.c#L488)[`mret`](rv.c#L658)[`mul`](rv.c#L610)[`mulh`](rv.c#L610)[`mulhsu`](rv.c#L610)[`mulhu`](rv.c#L610)[`or`](rv.c#L604)
+- [`ori`](rv.c#L604)[`rem`](rv.c#L624)[`remu`](rv.c#L626)[`sb`](rv.c#L500)[`sc.w`](rv.c#L554)[`sfence.vma`](rv.c#L678)[`sh`](rv.c#L500)[`sll`](rv.c#L594)
+- [`slli`](rv.c#L594)[`slt`](rv.c#L596)[`slti`](rv.c#L596)[`sltiu`](rv.c#L598)[`sltu`](rv.c#L598)[`sra`](rv.c#L602)[`srai`](rv.c#L602)[`sret`](rv.c#L658)
+- [`srl`](rv.c#L602)[`srli`](rv.c#L602)[`sub`](rv.c#L589)[`sw`](rv.c#L500)[`wfi`](rv.c#L675)[`xor`](rv.c#L600)[`xori`](rv.c#L600)
+
+## FAQ
+
+### Spaghetti code
+
+- `rv` was written in a way that takes maximal advantage of RISCV's instruction orthogonality.
+- `rv` also tries to strike a good balance between conciseness and readability.
+- Of course, being able to read this code at all requires intimate prior knowledge of the ISA encoding.
+
+### No switch statements
+
+- C only allows constant expressions in switch statements. In addition to an abundance of `break` statements using these would result in more bloated code in the author's opinion. As it turns out, you are actually free to reimplement this code with switch statements. See [LICENSE.txt](LICENSE.txt).
+
+### Not useful
+
+- [Ok](https://www.google.com/search?q=happy+smiley+thumbs+up+happy+cool+funny+ok&tbm=isch)
+
+### Slow
+
+- [Ok](https://www.google.com/search?q=happy+smiley+thumbs+up+happy+cool+funny+ok&tbm=isch)
+
+## Caveats
+
+- Written in C89.
+- Not actually written in C89, since it uses external names longer than 6 characters.
+- Doesn't use any integer types larger than 32 bits, even for multiplication, because it's written in C89.
+- Assumes width of integer types in a way that's not completely compliant with C89/99. Fix for this is coming soon, I'm working on a watertight `<stdint.h>` for C89.
+- Written in C89.

save-rvasm/funconfig.h

@@ -0,0 +1,17 @@
+#ifndef _FUNCONFIG_H
+#define _FUNCONFIG_H
+
+#define CH32V003           1
+#define FUNCONF_USE_DEBUGPRINTF 0
+#define FUNCONF_USE_UARTPRINTF  1
+#define FUNCONF_UART_PRINTF_BAUD 115200
+#define horizontalButtons 8
+#define verticalButtons 8
+#define NUM_LEDS (horizontalButtons * verticalButtons)
+
+// #define CH32V003J4M6_USE_PD6_AS_UART_TX
+#define FUNCONF_SYSTICK_USE_HCLK 1
+
+#define INTERNAL_INSPIRE_MATRIX
+
+#endif