[add] 添加代码和编译脚本

SConscript

@@ -0,0 +1,11 @@
+
+from building import *
+import rtconfig
+
+cwd     = GetCurrentDir()
+src     = Glob('*.c')
+CPPPATH = []
+
+group = DefineGroup('devmem', src, depend = ['PKG_USING_DEVMEM'], CPPPATH = CPPPATH)
+
+Return('group')

devmem.c

@@ -0,0 +1,75 @@
+#include <rthw.h>
+#include <rtthread.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+
+static void devmem(int argc, char **argv)
+{
+	rt_uint64_t tmp;
+	rt_uint32_t addr, value;
+    int access_type = 'w';
+
+	/* check args */
+	if (argc < 2) 
+    {
+		rt_kprintf("\nUsage:\t%s devmem address [type [data]]\n"
+                   "\taddress : memory address to act upon\n"
+                   "\ttype    : access operation type : [b]yte, [h]alfword, [w]ord\n"
+                   "\tdata    : data to be written\n\n", argv[0]);
+		return;
+	}
+
+	/* get address */
+	tmp = strtoll(argv[1], RT_NULL, 16);
+	addr = (rt_uint32_t)tmp;
+
+    /* get access_type */
+	if (argc >= 3) 
+    {
+		access_type = tolower(argv[2][0]);
+	}
+
+	if (argc >= 4) 
+    {
+		/* write value */
+		tmp = strtoll(argv[3], RT_NULL, 16);
+		value = (rt_uint32_t)tmp;
+
+		switch (access_type) 
+        {
+		case 'b':
+			*(volatile rt_uint8_t*)addr = (rt_uint8_t)value;
+			break;
+		case 'h':
+			*(volatile rt_uint16_t*)addr = (rt_uint16_t)value;
+			break;
+		case 'w':
+			*(volatile rt_uint32_t*)addr = (rt_uint32_t)value;
+			break;
+		default:
+			*(volatile rt_uint32_t*)addr = (rt_uint32_t)value;
+			break;
+		}
+	} 
+    else 
+    {
+		/* read value */
+		switch (access_type) 
+        {
+		case 'b':
+			rt_kprintf("0x%02x\n", *(volatile rt_uint8_t*)addr);
+			break;
+		case 'h':
+			rt_kprintf("0x%04x\n", *(volatile rt_uint16_t*)addr);
+			break;
+		case 'w':
+			rt_kprintf("0x%08x\n", *(volatile rt_uint32_t*)addr);
+			break;
+		default:
+			rt_kprintf("0x%08x\n", *(volatile rt_uint32_t*)addr);
+			break;
+		}
+	}
+}
+MSH_CMD_EXPORT(devmem, devmem address [type [data]]);