Move peripherals to devices directory

- modify Makefile to enable detect devices directory
- decouple PLIC and UART into separate files
- Bind RISC-V core to plic_t to enable sending interrupt from PLIC to
  core

Author: ChinYikMing

Makefile

@@ -47,8 +47,6 @@ OBJS_EXT :=
 
 ifeq ($(call has, SYSTEM), 1)
 OBJS_EXT += system.o
-OBJS_EXT += plic.o
-OBJS_EXT += uart.o
 endif
 
 # Integer Multiplication and Division instructions
@@ -230,11 +228,23 @@ ifeq ($(call has, GDBSTUB), 1)
 $(OBJS): $(GDBSTUB_LIB)
 endif
 
+# Peripherals for system emulation
+ifeq ($(call has, SYSTEM), 1)
+DEV_OUT := $(OUT)/devices
+DEV_SRC := src/devices
+$(DEV_OUT)/%.o: $(DEV_SRC)/%.c $(deps_emcc)
+	$(Q)mkdir -p $(DEV_OUT)
+	$(VECHO) "  CC\t$@\n"
+	$(Q)$(CC) -o $@ $(CFLAGS) $(CFLAGS_emcc) -c -MMD -MF $@.d $<
+DEV_OBJS := $(patsubst $(DEV_SRC)/%.c, $(DEV_OUT)/%.o, $(wildcard $(DEV_SRC)/*.c))
+deps += $(DEV_OBJS:%.o=%.o.d)
+endif
+
 $(OUT)/%.o: src/%.c $(deps_emcc)
 	$(VECHO) "  CC\t$@\n"
 	$(Q)$(CC) -o $@ $(CFLAGS) $(CFLAGS_emcc) -c -MMD -MF $@.d $<
 
-$(BIN): $(OBJS)
+$(BIN): $(OBJS) $(DEV_OBJS)
 	$(VECHO) "  LD\t$@\n"
 	$(Q)$(CC) -o $@ $(CFLAGS_emcc) $^ $(LDFLAGS)
 
@@ -331,7 +341,7 @@ endif
 endif
 
 clean:
-	$(RM) $(BIN) $(OBJS) $(HIST_BIN) $(HIST_OBJS) $(deps) $(WEB_FILES) $(CACHE_OUT) src/rv32_jit.c
+	$(RM) $(BIN) $(OBJS) $(DEV_OBJS) $(HIST_BIN) $(HIST_OBJS) $(deps) $(WEB_FILES) $(CACHE_OUT) src/rv32_jit.c
 distclean: clean
 	-$(RM) $(DOOM_DATA) $(QUAKE_DATA)
 	$(RM) -r $(TIMIDITY_DATA)

src/plic.c renamed to src/devices/plic.c

@@ -1,9 +1,18 @@
+/*
+ * rv32emu is freely redistributable under the MIT License. See the file
+ * "LICENSE" for information on usage and redistribution of this file.
+ */
+
+#include <assert.h>
+#include <stdlib.h>
+
 #include "plic.h"
+#include "../riscv.h"
+#include "../riscv_private.h"
 
-void plic_update_interrupts(riscv_t *rv)
+void plic_update_interrupts(plic_t *plic)
 {
-    vm_attr_t *attr = PRIV(rv);
-    plic_t *plic = attr->plic;
+    riscv_t *rv = (riscv_t *) plic->rv;
 
     /* Update pending interrupts */
     plic->ip |= plic->active & ~plic->masked;
@@ -15,11 +24,8 @@ void plic_update_interrupts(riscv_t *rv)
         rv->csr_sip &= ~SIP_SEIP;
 }
 
-uint32_t plic_read(riscv_t *rv, const uint32_t addr)
+uint32_t plic_read(plic_t *plic, const uint32_t addr)
 {
-    vm_attr_t *attr = PRIV(rv);
-    plic_t *plic = attr->plic;
-
     /* no priority support: source priority hardwired to 1 */
     if (1 <= addr && addr <= 31)
         return 0;
@@ -54,11 +60,8 @@ uint32_t plic_read(riscv_t *rv, const uint32_t addr)
     return plic_read_val;
 }
 
-void plic_write(riscv_t *rv, const uint32_t addr, uint32_t value)
+void plic_write(plic_t *plic, const uint32_t addr, uint32_t value)
 {
-    vm_attr_t *attr = PRIV(rv);
-    plic_t *plic = attr->plic;
-
     /* no priority support: source priority hardwired to 1 */
     if (1 <= addr && addr <= 31)
         return;
@@ -81,3 +84,11 @@ void plic_write(riscv_t *rv, const uint32_t addr, uint32_t value)
 
     return;
 }
+
+plic_t *plic_new()
+{
+    plic_t *plic = calloc(1, sizeof(plic_t));
+    assert(plic);
+
+    return plic;
+}

src/devices/plic.h

@@ -0,0 +1,31 @@
+/*
+ * rv32emu is freely redistributable under the MIT License. See the file
+ * "LICENSE" for information on usage and redistribution of this file.
+ */
+
+#pragma once
+
+#include <stdint.h>
+
+/* PLIC */
+typedef struct {
+    uint32_t masked;
+    uint32_t ip;
+    uint32_t ie;
+    /* state of input interrupt lines (level-triggered), set by environment */
+    uint32_t active;
+    /* RISC-V instance to receive PLIC interrupt */
+    void *rv;
+} plic_t;
+
+/* update PLIC status */
+void plic_update_interrupts(plic_t *plic);
+
+/* read a word from PLIC */
+uint32_t plic_read(plic_t *plic, const uint32_t addr);
+
+/* write a word to PLIC */
+void plic_write(plic_t *plic, const uint32_t addr, uint32_t value);
+
+/* create a PLIC instance */
+plic_t *plic_new();

src/uart.c renamed to src/devices/uart.c

@@ -1,14 +1,20 @@
+/*
+ * rv32emu is freely redistributable under the MIT License. See the file
+ * "LICENSE" for information on usage and redistribution of this file.
+ */
+
 #include <errno.h>
 #include <poll.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
-
-#include "io.h"
+#include <assert.h>
 
 /* Emulate 8250 (plain, without loopback mode support) */
 
+#include "uart.h"
+
 #define U8250_INT_THRE 1
 
 void u8250_update_interrupts(u8250_state_t *uart)
@@ -142,3 +148,11 @@ void u8250_write(u8250_state_t *uart, uint32_t addr, uint32_t value)
 {
     u8250_reg_write(uart, addr, value);
 }
+
+u8250_state_t *u8250_new()
+{
+    u8250_state_t *uart = calloc(1, sizeof(u8250_state_t));
+    assert(uart);
+
+    return uart;
+}

src/devices/uart.h

@@ -0,0 +1,37 @@
+/*
+ * rv32emu is freely redistributable under the MIT License. See the file
+ * "LICENSE" for information on usage and redistribution of this file.
+ */
+
+#pragma once
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#define IRQ_UART 1
+#define IRQ_UART_BIT (1 << IRQ_UART)
+
+typedef struct {
+    uint8_t dll, dlh;                  /* divisor (ignored) */
+    uint8_t lcr;                       /* UART config */
+    uint8_t ier;                       /* interrupt config */
+    uint8_t current_int, pending_ints; /* interrupt status */
+    uint8_t mcr;       /* other output signals, loopback mode (ignored) */
+    int in_fd, out_fd; /* I/O handling */
+    bool in_ready;
+} u8250_state_t;
+
+/* update UART status */
+void u8250_update_interrupts(u8250_state_t *uart);
+
+/* poll UART status */
+void u8250_check_ready(u8250_state_t *uart);
+
+/* read a word from UART */
+uint32_t u8250_read(u8250_state_t *uart, uint32_t addr);
+
+/* write a word to UART */
+void u8250_write(u8250_state_t *uart, uint32_t addr, uint32_t value);
+
+/* create a UART instance */
+u8250_state_t *u8250_new();

src/emulate.c

@@ -10,10 +10,6 @@
 #include <stdlib.h>
 #include <string.h>
 
-#if RV32_HAS(SYSTEM)
-#include "plic.h"
-#endif /* RV32_HAS(SYSTEM) */
-
 #ifdef __EMSCRIPTEN__
 #include <emscripten.h>
 #endif

src/io.c

@@ -15,22 +15,6 @@
 
 #include "io.h"
 
-u8250_state_t *u8250_new()
-{
-    u8250_state_t *uart = calloc(1, sizeof(u8250_state_t));
-    assert(uart);
-
-    return uart;
-}
-
-plic_t *plic_new()
-{
-    plic_t *plic = calloc(1, sizeof(plic_t));
-    assert(plic);
-
-    return plic;
-}
-
 static uint8_t *data_memory_base;
 
 memory_t *memory_new(uint32_t size)

src/io.h

@@ -9,43 +9,7 @@
 #include <stdint.h>
 #include <string.h>
 
-/* UART */
-
-#define IRQ_UART 1
-#define IRQ_UART_BIT (1 << IRQ_UART)
-
-typedef struct {
-    uint8_t dll, dlh;                  /**< divisor (ignored) */
-    uint8_t lcr;                       /**< UART config */
-    uint8_t ier;                       /**< interrupt config */
-    uint8_t current_int, pending_ints; /**< interrupt status */
-    /* other output signals, loopback mode (ignored) */
-    uint8_t mcr;
-    /* I/O handling */
-    int in_fd, out_fd;
-    bool in_ready;
-} u8250_state_t;
-void u8250_update_interrupts(u8250_state_t *uart);
-void u8250_check_ready(u8250_state_t *uart);
-
-uint32_t u8250_read(u8250_state_t *uart, uint32_t addr);
-
-void u8250_write(u8250_state_t *uart, uint32_t addr, uint32_t value);
-
-/* create a UART controller */
-u8250_state_t *u8250_new();
-
-typedef struct {
-    uint32_t masked;
-    uint32_t ip;
-    uint32_t ie;
-    /* state of input interrupt lines (level-triggered), set by environment */
-    uint32_t active;
-} plic_t;
-
-/* create a PLIC core */
-plic_t *plic_new();
-
+/* main memory */
 typedef struct {
     uint8_t *mem_base;
     uint64_t mem_size;

src/plic.h

@@ -367,8 +367,9 @@ riscv_t *rv_create(riscv_user_t rv_attr)
         /* setup PLIC */
         attr->plic = plic_new();
         assert(attr->plic);
+        attr->plic->rv = rv;
 
-        /* setup PLIC */
+        /* setup UART */
         attr->uart = u8250_new();
         assert(attr->uart);
         attr->uart->in_fd = 0;