将mstStartup和slvStartup代码合二为一；增加mtime的驱动代码

tb/sw/src/clint.c

@@ -0,0 +1,54 @@
+#include "clint.h"
+
+
+volatile const uint32_t * const mtime_high  = (volatile const uint32_t*)(CLINT_BASE + CLINT_MTIME_HIGH);
+volatile const uint32_t * const mtime_low   = (volatile const uint32_t*)(CLINT_BASE + CLINT_MTIME_LOW);
+volatile uint32_t * const mtimecmp_high     = (volatile const uint32_t*)(CLINT_BASE + CLINT_MTIMECMP_HIGH);
+volatile uint32_t * const mtimecmp_low      = (volatile const uint32_t*)(CLINT_BASE + CLINT_MTIMECMP_LOW);
+volatile uint32_t mtimer_int_flag = 0;
+
+void set_mtimecmp(uint64_t value)
+{
+    *mtimecmp_high = 0xFFFFFFFF; // 先写入高 32 位为全 1（禁用中断）
+    *mtimecmp_low  = (uint32_t)value; // 写入低 32 位
+    *mtimecmp_high = (uint32_t)(value >> 32); // 写入高 32 位
+}
+
+
+uint64_t read_mtimer()
+{
+    uint32_t hi, lo;
+    do {
+        hi = *mtime_high;  // 读取高 32 位
+        lo = *mtime_low;   // 读取低 32 位
+    } while (hi != *mtime_high); // 检查高 32 位是否变化（避免进位）
+    return (((uint64_t)hi << 32) | lo);
+}
+
+void enable_mtimer_int() 
+{
+    __asm__ volatile ("csrs mie, %0" :: "r"(0x80));    // mie.MTIE = 1
+    __asm__ volatile ("csrs mstatus, %0" :: "r"(0x8)); // mstatus.MIE = 1
+}
+
+void disable_mtimer_int()
+{
+    __asm__ volatile ("csrc mie, %0" :: "r"(0x80));    // mie.MTIE = 0
+    __asm__ volatile ("csrc mstatus, %0" :: "r"(0x8)); // mstatus.MIE = 0
+}
+
+void set_mtimer(uint32_t delta_t)
+{
+    uint64_t t;
+
+    t = read_mtimer();
+    t += delta_t;
+    set_mtimecmp(t);
+    #if 0
+    uint64_t t;
+
+    t = *(volatile uint64_t *)(CLINT_BASE + CLINT_MTIME_LOW);
+    t += delta_t;
+    *(volatile uint64_t *)(CLINT_BASE + CLINT_MTIMECMP_LOW) = t;
+    #endif
+}