[elf] Get back dynamic loader

Author: onelife

components/libc/libdl/arch/arm.c

@@ -0,0 +1,121 @@
+/*
+ * Copyright (c) 2006-2018, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * 
+ * Change Logs:
+ * Date           Author      Notes
+ * 2018/08/29     Bernard     first version
+ */
+
+#include "../dlmodule.h"
+#include "../dlelf.h"
+
+#ifdef __arm__
+int dlmodule_relocate(struct rt_dlmodule *module, Elf32_Rel *rel, Elf32_Addr sym_val)
+{
+    Elf32_Addr *where, tmp;
+    Elf32_Sword addend, offset;
+    rt_uint32_t upper, lower, sign, j1, j2;
+
+    where = (Elf32_Addr *)((rt_uint8_t *)module->mem_space
+                           + rel->r_offset
+                           - module->vstart_addr);
+    switch (ELF32_R_TYPE(rel->r_info))
+    {
+    case R_ARM_NONE:
+        break;
+    case R_ARM_ABS32:
+        *where += (Elf32_Addr)sym_val;
+        RT_DEBUG_LOG(RT_DEBUG_MODULE, ("R_ARM_ABS32: %x -> %x\n",
+                                       where, *where));
+        break;
+    case R_ARM_PC24:
+    case R_ARM_PLT32:
+    case R_ARM_CALL:
+    case R_ARM_JUMP24:
+        addend = *where & 0x00ffffff;
+        if (addend & 0x00800000)
+            addend |= 0xff000000;
+        tmp = sym_val - (Elf32_Addr)where + (addend << 2);
+        tmp >>= 2;
+        *where = (*where & 0xff000000) | (tmp & 0x00ffffff);
+        RT_DEBUG_LOG(RT_DEBUG_MODULE, ("R_ARM_PC24: %x -> %x\n",
+                                       where, *where));
+        break;
+    case R_ARM_REL32:
+        *where += sym_val - (Elf32_Addr)where;
+        RT_DEBUG_LOG(RT_DEBUG_MODULE,
+                     ("R_ARM_REL32: %x -> %x, sym %x, offset %x\n",
+                      where, *where, sym_val, rel->r_offset));
+        break;
+    case R_ARM_V4BX:
+        *where &= 0xf000000f;
+        *where |= 0x01a0f000;
+        break;
+
+    case R_ARM_GLOB_DAT:
+    case R_ARM_JUMP_SLOT:
+        *where = (Elf32_Addr)sym_val;
+        RT_DEBUG_LOG(RT_DEBUG_MODULE, ("R_ARM_JUMP_SLOT: 0x%x -> 0x%x 0x%x\n",
+                                       where, *where, sym_val));
+        break;
+#if 0        /* To do */
+    case R_ARM_GOT_BREL:
+        temp   = (Elf32_Addr)sym_val;
+        *where = (Elf32_Addr)&temp;
+        RT_DEBUG_LOG(RT_DEBUG_MODULE, ("R_ARM_GOT_BREL: 0x%x -> 0x%x 0x%x\n",
+                                       where, *where, sym_val));
+        break;
+#endif
+
+    case R_ARM_RELATIVE:
+        *where = (Elf32_Addr)sym_val + *where;
+        RT_DEBUG_LOG(RT_DEBUG_MODULE, ("R_ARM_RELATIVE: 0x%x -> 0x%x 0x%x\n",
+                                       where, *where, sym_val));
+        break;
+    case R_ARM_THM_CALL:
+    case R_ARM_THM_JUMP24:
+        upper  = *(rt_uint16_t *)where;
+        lower  = *(rt_uint16_t *)((Elf32_Addr)where + 2);
+
+        sign   = (upper >> 10) & 1;
+        j1     = (lower >> 13) & 1;
+        j2     = (lower >> 11) & 1;
+        offset = (sign << 24) |
+                 ((~(j1 ^ sign) & 1) << 23) |
+                 ((~(j2 ^ sign) & 1) << 22) |
+                 ((upper & 0x03ff) << 12) |
+                 ((lower & 0x07ff) << 1);
+        if (offset & 0x01000000)
+            offset -= 0x02000000;
+        offset += sym_val - (Elf32_Addr)where;
+
+        if (!(offset & 1) ||
+            offset <= (rt_int32_t)0xff000000 ||
+            offset >= (rt_int32_t)0x01000000)
+        {
+            rt_kprintf("Module: Only Thumb addresses allowed\n");
+
+            return -1;
+        }
+
+        sign = (offset >> 24) & 1;
+        j1   = sign ^ (~(offset >> 23) & 1);
+        j2   = sign ^ (~(offset >> 22) & 1);
+        *(rt_uint16_t *)where = (rt_uint16_t)((upper & 0xf800) |
+                                              (sign << 10) |
+                                              ((offset >> 12) & 0x03ff));
+        *(rt_uint16_t *)(where + 2) = (rt_uint16_t)((lower & 0xd000) |
+                                                    (j1 << 13) | (j2 << 11) |
+                                                    ((offset >> 1) & 0x07ff));
+        upper = *(rt_uint16_t *)where;
+        lower = *(rt_uint16_t *)((Elf32_Addr)where + 2);
+        break;
+    default:
+        return -1;
+    }
+
+    return 0;
+}
+#endif

components/libc/libdl/dlclose.c

@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2006-2018, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2010-11-17     yi.qiu       first version
+ */
+
+#include <rtthread.h>
+#include <rtm.h>
+
+#include "dlmodule.h"
+
+int dlclose(void *handle)
+{
+    struct rt_dlmodule *module;
+
+    RT_ASSERT(handle != RT_NULL);
+
+    module = (struct rt_dlmodule *)handle;
+
+    rt_enter_critical();
+    module->nref--;
+    if (module->nref <= 0)
+    {
+        rt_exit_critical();
+
+        dlmodule_destroy(module);
+    }
+    else
+    {
+        rt_exit_critical();
+    }
+
+    return RT_TRUE;
+}
+RTM_EXPORT(dlclose)