support elfloader for shared object and relocatable object

1. elfloader for shared object
example: TencentOS-tiny\examples\elfloader_shared_object
keil: TencentOS-tiny\board\TencentOS_tiny_EVB_MX_Plus\KEIL\elfloader_shared_object

2. elfloader for relocatable object:
example: TencentOS-tiny\examples\elfloader_relocatable_object
keil: TencentOS-tiny\board\TencentOS_tiny_EVB_MX_Plus\KEIL\elfloader_relocatable_object

3. TODO:
- add icache/dcache flush when module is loaded
- support more relocation type in elfloader_arch_relocate

components/elfloader/common/include/elf/elf32.h

@@ -0,0 +1,183 @@
+/*----------------------------------------------------------------------------
+ * Tencent is pleased to support the open source community by making TencentOS
+ * available.
+ *
+ * Copyright (C) 2019 THL A29 Limited, a Tencent company. All rights reserved.
+ * If you have downloaded a copy of the TencentOS binary from Tencent, please
+ * note that the TencentOS binary is licensed under the BSD 3-Clause License.
+ *
+ * If you have downloaded a copy of the TencentOS source code from Tencent,
+ * please note that TencentOS source code is licensed under the BSD 3-Clause
+ * License, except for the third-party components listed below which are
+ * subject to different license terms. Your integration of TencentOS into your
+ * own projects may require compliance with the BSD 3-Clause License, as well
+ * as the other licenses applicable to the third-party components included
+ * within TencentOS.
+ *---------------------------------------------------------------------------*/
+
+#ifndef _ELF32_H_
+#define  _ELF32_H_
+
+#define EI_NIDENT   16
+
+typedef int32_t     elf32_sword;
+typedef uint32_t    elf32_word;
+typedef uint16_t    elf32_half;
+typedef uint32_t    elf32_off;
+typedef uint32_t    elf32_addr;
+
+/* elf header */
+typedef struct elf32_ehdr {
+    unsigned char   e_ident[EI_NIDENT];     /* ident bytes */
+    elf32_half      e_type;                 /* file type */
+    elf32_half      e_machine;              /* target machine */
+    elf32_word      e_version;              /* file version */
+    elf32_addr      e_entry;                /* start address */
+    elf32_off       e_phoff;                /* phdr file offset */
+    elf32_off       e_shoff;                /* shdr file offset */
+    elf32_word      e_flags;                /* file flags */
+    elf32_half      e_ehsize;               /* sizeof ehdr */
+    elf32_half      e_phentsize;            /* sizeof phdr */
+    elf32_half      e_phnum;                /* number phdrs */
+    elf32_half      e_shentsize;            /* sizeof shdr */
+    elf32_half      e_shnum;                /* number shdrs */
+    elf32_half      e_shstrndx;             /* shdr string index */
+} elf32_ehdr_t;
+
+/* values for e_type. */
+#define ET_NONE     0                       /* unknown type. */
+#define ET_REL      1                       /* relocatable. */
+#define ET_EXEC     2                       /* executable. */
+#define ET_DYN      3                       /* shared object. */
+
+/* section header */
+typedef struct elf32_shdr {
+    elf32_word      sh_name;                /* section name */
+    elf32_word      sh_type;                /* SHT_... */
+    elf32_word      sh_flags;               /* SHF_... */
+    elf32_addr      sh_addr;                /* virtual address */
+    elf32_off       sh_offset;              /* file offset */
+    elf32_word      sh_size;                /* section size */
+    elf32_word      sh_link;                /* misc info */
+    elf32_word      sh_info;                /* misc info */
+    elf32_word      sh_addralign;           /* memory alignment */
+    elf32_word      sh_entsize;             /* entry size if table */
+} elf32_shdr_t;
+
+/* values for sh_type */
+#define SHT_NULL        0                   /* inactive */
+#define SHT_PROGBITS    1                   /* program defined information */
+#define SHT_SYMTAB      2                   /* symbol table section */
+#define SHT_STRTAB      3                   /* string table section */
+#define SHT_RELA        4                   /* relocation section with addends*/
+#define SHT_HASH        5                   /* symbol hash table section */
+#define SHT_DYNAMIC     6                   /* dynamic section */
+#define SHT_NOTE        7                   /* note section */
+#define SHT_NOBITS      8                   /* no space section */
+#define SHT_REL         9                   /* relation section without addends */
+#define SHT_SHLIB       10                  /* reserved - purpose unknown */
+#define SHT_DYNSYM      11                  /* dynamic symbol table section */
+#define SHT_LOPROC      0x70000000          /* reserved range for processor */
+#define SHT_HIPROC      0x7fffffff          /* specific section header types */
+#define SHT_LOUSER      0x80000000          /* reserved range for application */
+#define SHT_HIUSER      0xffffffff          /* specific indexes */
+
+/* values for sh_flags */
+#define SHF_WRITE       1                   /* writable */
+#define SHF_ALLOC       2                   /* occupies memory */
+#define SHF_EXECINSTR   4                   /* executable */
+
+typedef struct elf32_rel {
+    elf32_addr      r_offset;               /* location to be relocated. */
+    elf32_word      r_info;                 /* relocation type and symbol index. */
+} elf32_rel_t;
+
+typedef struct elf32_rela {
+    elf32_addr      r_offset;               /* location to be relocated. */
+    elf32_word      r_info;                 /* relocation type and symbol index. */
+    elf32_sword     r_addend;               /* addend. */
+} elf32_rela_t;
+
+typedef struct elf32_sym {
+    elf32_word      st_name;                /* string table index of name. */
+    elf32_addr      st_value;               /* symbol value. */
+    elf32_word      st_size;                /* size of associated object. */
+    unsigned char   st_info;                /* type and binding information. */
+    unsigned char   st_other;               /* reserved (not used). */
+    elf32_half      st_shndx;               /* section index of symbol. */
+} elf32_sym_t;
+
+/* values for st_info(binding) */
+#define STB_LOCAL           0
+#define STB_GLOBAL          1
+#define STB_WEAK            2
+
+/* values for st_info(type) */
+#define STT_NOTYPE          0
+#define STT_OBJECT          1
+#define STT_FUNC            2
+#define STT_SECTION         3
+#define STT_FILE            4
+
+/* values for st_shndx */
+#define SHN_ABS             0xFFF1
+#define SHN_COMMON          0xFFF2
+#define SHN_UNDEF           0x0000
+
+#define ELF32_SYM_BINDING(info)     ((info) >> 4)
+#define ELF32_SYM_TYPE(info)        ((info) & 0x0F)
+
+typedef struct elf32_dyn {
+    elf32_sword     d_tag;                  /* DT_... */
+    union {
+        elf32_word  d_val;
+        elf32_addr  d_ptr;
+    } d_un;
+} elf32_dyn_t;
+
+/* values for d_tag */
+#define DT_NULL             0x00
+#define DT_PLTRELSZ         0x02
+#define DT_PLTGOT           0x03
+#define DT_HASH             0x04
+#define DT_STRTAB           0x05
+#define DT_SYMTAB           0x06
+#define DT_STRSZ            0x0a
+#define DT_SYMENT           0x0b
+#define DT_REL              0x11
+#define DT_RELSZ            0x12
+#define DT_RELENT           0x13
+#define DT_PLTREL           0x14
+#define DT_JMPREL           0x17
+
+/* program header */
+typedef struct elf32_phdr {
+    elf32_word      p_type;                 /* PHT_... */
+    elf32_off       p_offset;               /* file offset */
+    elf32_addr      p_vaddr;                /* virtual address */
+    elf32_addr      p_paddr;                /* physical address */
+    elf32_word      p_filesz;               /* file size */
+    elf32_word      p_memsz;                /* memory size */
+    elf32_word      p_flags;                /* read write properties */
+    elf32_word      p_align;                /* alignment attribute, 2 ^ p_align */
+} elf32_phdr_t;
+
+/* values for p_type */
+#define PHT_LOAD            0x01
+#define PHT_DYNAMIC         0x02
+
+#define ELF32_R_SYM(info)            ((info) >> 8)
+#define ELF32_R_TYPE(info)           ((unsigned char)(info))
+
+#define ELF_MAGIC_HEADER            "\177ELF\001\001\001"
+#define ELF_MAGIC_HEADER_SIZE         7
+
+static const unsigned char elf_header_magic[] = {
+    0x7f, 0x45, 0x4c, 0x46,     /* Magic:   0x7f, 'E', 'L', 'F' */
+    0x01,                       /* Class:   ELF32 */
+    0x01,                       /* Data:    2's complement, 'little endian */
+    0x01,                       /* Version: 1(current) */
+};
+
+#endif /* _ELF32_H_ */
+

components/elfloader/common/include/tos_elfloader.h

@@ -0,0 +1,74 @@
+/*----------------------------------------------------------------------------
+ * Tencent is pleased to support the open source community by making TencentOS
+ * available.
+ *
+ * Copyright (C) 2019 THL A29 Limited, a Tencent company. All rights reserved.
+ * If you have downloaded a copy of the TencentOS binary from Tencent, please
+ * note that the TencentOS binary is licensed under the BSD 3-Clause License.
+ *
+ * If you have downloaded a copy of the TencentOS source code from Tencent,
+ * please note that TencentOS source code is licensed under the BSD 3-Clause
+ * License, except for the third-party components listed below which are
+ * subject to different license terms. Your integration of TencentOS into your
+ * own projects may require compliance with the BSD 3-Clause License, as well
+ * as the other licenses applicable to the third-party components included
+ * within TencentOS.
+ *---------------------------------------------------------------------------*/
+
+#ifndef _TOS_ELFLOADER_H_
+#define  _TOS_ELFLOADER_H_
+
+#include "tos_k.h"
+
+#include "elf/elf32.h"
+
+#include "tos_elfloader_err.h"
+#include "tos_elfloader_fd_read.h"
+#include "tos_elfloader_symbol.h"
+#include "tos_elfloader_symtab.h"
+#include "tos_elfloader_relocate.h"
+
+typedef struct el_section_st {
+    uint8_t         shndx;
+    void           *address;
+} el_section_t;
+
+typedef struct el_obj_info_st {
+    el_section_t    bss;
+    el_section_t    data;
+    el_section_t    rodata;
+    el_section_t    text;
+} el_obj_info_t;
+
+typedef struct el_so_info_st {
+    int32_t         load_bias;
+} el_so_info_t;
+
+typedef union el_info_un {
+    el_obj_info_t   obj;
+    el_so_info_t    so;
+} el_info_t;
+
+typedef struct el_module_st {
+    int         fd;
+
+    void       *base;
+
+    el_info_t   info;
+
+    uint32_t    symtab_offset;
+    uint32_t    symtab_size;
+    uint32_t    symtab_entsize;
+
+    uint32_t    strtab_offset;
+} el_module_t;
+
+__API__ el_err_t tos_elfloader_load(el_module_t *module, int fd);
+
+__API__ el_err_t tos_elfloader_unload(el_module_t *module);
+
+__API__ void *tos_elfloader_find_symbol(el_module_t *module, char *symbol);
+
+
+#endif /* _TOS_ELFLOADER_H_ */
+

components/elfloader/common/include/tos_elfloader_err.h

@@ -0,0 +1,38 @@
+/*----------------------------------------------------------------------------
+ * Tencent is pleased to support the open source community by making TencentOS
+ * available.
+ *
+ * Copyright (C) 2019 THL A29 Limited, a Tencent company. All rights reserved.
+ * If you have downloaded a copy of the TencentOS binary from Tencent, please
+ * note that the TencentOS binary is licensed under the BSD 3-Clause License.
+ *
+ * If you have downloaded a copy of the TencentOS source code from Tencent,
+ * please note that TencentOS source code is licensed under the BSD 3-Clause
+ * License, except for the third-party components listed below which are
+ * subject to different license terms. Your integration of TencentOS into your
+ * own projects may require compliance with the BSD 3-Clause License, as well
+ * as the other licenses applicable to the third-party components included
+ * within TencentOS.
+ *---------------------------------------------------------------------------*/
+
+#ifndef _TOS_ELFLOADER_ERR_H_
+#define  _TOS_ELFLOADER_ERR_H_
+
+typedef enum elfloader_err_en {
+    ELFLOADER_ERR_NONE,
+    ELFLOADER_ERR_HEADER_INVALID,
+    ELFLOADER_ERR_TYPE_INVALID,
+    ELFLOADER_ERR_NO_DYN,
+    ELFLOADER_ERR_NO_SYMTAB,
+    ELFLOADER_ERR_NO_STRTAB,
+    ELFLOADER_ERR_NO_TEXT,
+    ELFLOADER_ERR_NO_LOAD_SEGMENTS,
+    ELFLOADER_ERR_FD_READ_FAILED,
+    ELFLOADER_ERR_SECTION_NOT_FOUND,
+    ELFLOADER_ERR_SYM_NOT_FOUND,
+    ELFLOADER_ERR_OUT_OF_MEMORY,
+    ELFLOADER_ERR_PTR_NULL,
+} el_err_t;
+
+#endif /* _TOS_ELFLOADER_ERR_H_ */
+

components/elfloader/common/include/tos_elfloader_fd_read.h

@@ -0,0 +1,24 @@
+/*----------------------------------------------------------------------------
+ * Tencent is pleased to support the open source community by making TencentOS
+ * available.
+ *
+ * Copyright (C) 2019 THL A29 Limited, a Tencent company. All rights reserved.
+ * If you have downloaded a copy of the TencentOS binary from Tencent, please
+ * note that the TencentOS binary is licensed under the BSD 3-Clause License.
+ *
+ * If you have downloaded a copy of the TencentOS source code from Tencent,
+ * please note that TencentOS source code is licensed under the BSD 3-Clause
+ * License, except for the third-party components listed below which are
+ * subject to different license terms. Your integration of TencentOS into your
+ * own projects may require compliance with the BSD 3-Clause License, as well
+ * as the other licenses applicable to the third-party components included
+ * within TencentOS.
+ *---------------------------------------------------------------------------*/
+
+#ifndef _TOS_ELFLOADER_FD_READ_H_
+#define  _TOS_ELFLOADER_FD_READ_H_
+
+__KNL__ el_err_t elfloader_fd_read(int fd, uint32_t offset, void *buf, size_t len);
+
+#endif /* _TOS_ELFLOADER_FD_READ_H_ */
+

components/elfloader/common/include/tos_elfloader_relocate.h

@@ -0,0 +1,24 @@
+/*----------------------------------------------------------------------------
+ * Tencent is pleased to support the open source community by making TencentOS
+ * available.
+ *
+ * Copyright (C) 2019 THL A29 Limited, a Tencent company. All rights reserved.
+ * If you have downloaded a copy of the TencentOS binary from Tencent, please
+ * note that the TencentOS binary is licensed under the BSD 3-Clause License.
+ *
+ * If you have downloaded a copy of the TencentOS source code from Tencent,
+ * please note that TencentOS source code is licensed under the BSD 3-Clause
+ * License, except for the third-party components listed below which are
+ * subject to different license terms. Your integration of TencentOS into your
+ * own projects may require compliance with the BSD 3-Clause License, as well
+ * as the other licenses applicable to the third-party components included
+ * within TencentOS.
+ *---------------------------------------------------------------------------*/
+
+#ifndef _TOS_ELFLOADER_RELOCATE_H_
+#define  _TOS_ELFLOADER_RELOCATE_H_
+
+__KNL__ void elfloader_arch_relocate(uint32_t reloc_addr, int32_t load_bias, uint32_t addr, elf32_rela_t *rela, int is_rela);
+
+#endif /* _TOS_ELFLOADER_RELOCATE_H_ */
+

components/elfloader/common/include/tos_elfloader_symbol.h

@@ -0,0 +1,29 @@
+/*----------------------------------------------------------------------------
+ * Tencent is pleased to support the open source community by making TencentOS
+ * available.
+ *
+ * Copyright (C) 2019 THL A29 Limited, a Tencent company. All rights reserved.
+ * If you have downloaded a copy of the TencentOS binary from Tencent, please
+ * note that the TencentOS binary is licensed under the BSD 3-Clause License.
+ *
+ * If you have downloaded a copy of the TencentOS source code from Tencent,
+ * please note that TencentOS source code is licensed under the BSD 3-Clause
+ * License, except for the third-party components listed below which are
+ * subject to different license terms. Your integration of TencentOS into your
+ * own projects may require compliance with the BSD 3-Clause License, as well
+ * as the other licenses applicable to the third-party components included
+ * within TencentOS.
+ *---------------------------------------------------------------------------*/
+
+#ifndef _TOS_ELFLOADER_SYMBOL_H_
+#define  _TOS_ELFLOADER_SYMBOL_H_
+
+typedef struct el_symbol_st {
+    const char *name;
+    void       *value;
+} el_symbol_t;
+
+extern const el_symbol_t el_symbols[];
+
+#endif /* _TOS_ELFLOADER_SYMBOL_H_ */
+

components/elfloader/common/include/tos_elfloader_symtab.h

@@ -0,0 +1,24 @@
+/*----------------------------------------------------------------------------
+ * Tencent is pleased to support the open source community by making TencentOS
+ * available.
+ *
+ * Copyright (C) 2019 THL A29 Limited, a Tencent company. All rights reserved.
+ * If you have downloaded a copy of the TencentOS binary from Tencent, please
+ * note that the TencentOS binary is licensed under the BSD 3-Clause License.
+ *
+ * If you have downloaded a copy of the TencentOS source code from Tencent,
+ * please note that TencentOS source code is licensed under the BSD 3-Clause
+ * License, except for the third-party components listed below which are
+ * subject to different license terms. Your integration of TencentOS into your
+ * own projects may require compliance with the BSD 3-Clause License, as well
+ * as the other licenses applicable to the third-party components included
+ * within TencentOS.
+ *---------------------------------------------------------------------------*/
+
+#ifndef _TOS_ELFLOADER_SYMTAB_H_
+#define  _TOS_ELFLOADER_SYMTAB_H_
+
+__KNL__ void *elfloader_symtab_lookup(char *name);
+
+#endif /* _TOS_ELFLOADER_SYMTAB_H_ */
+

components/elfloader/common/tos_elfloader_fd_read-vfs.c

@@ -0,0 +1,40 @@
+/*----------------------------------------------------------------------------
+ * Tencent is pleased to support the open source community by making TencentOS
+ * available.
+ *
+ * Copyright (C) 2019 THL A29 Limited, a Tencent company. All rights reserved.
+ * If you have downloaded a copy of the TencentOS binary from Tencent, please
+ * note that the TencentOS binary is licensed under the BSD 3-Clause License.
+ *
+ * If you have downloaded a copy of the TencentOS source code from Tencent,
+ * please note that TencentOS source code is licensed under the BSD 3-Clause
+ * License, except for the third-party components listed below which are
+ * subject to different license terms. Your integration of TencentOS into your
+ * own projects may require compliance with the BSD 3-Clause License, as well
+ * as the other licenses applicable to the third-party components included
+ * within TencentOS.
+ *---------------------------------------------------------------------------*/
+
+#include "tos_vfs.h"
+#include "tos_elfloader.h"
+
+/*
+ ATTENTION:
+    if you wanna load the so/obj laying on your flash, you should implement "elfloader_fd_read"
+    with flash driver read/write operation.
+
+    very easy to use whether your module is on a file system or raw flash.
+ */
+__KNL__ __WEAK__ el_err_t elfloader_fd_read(int fd, uint32_t offset, void *buf, size_t len)
+{
+    if (tos_vfs_lseek(fd, (vfs_off_t)offset, VFS_SEEK_SET) < 0) {
+        return ELFLOADER_ERR_FD_READ_FAILED;
+    }
+
+    if (tos_vfs_read(fd, buf, len) < 0) {
+        return ELFLOADER_ERR_FD_READ_FAILED;
+    }
+
+    return ELFLOADER_ERR_NONE;
+}
+

components/elfloader/common/tos_elfloader_relocate-arm.c

@@ -0,0 +1,70 @@
+/*----------------------------------------------------------------------------
+ * Tencent is pleased to support the open source community by making TencentOS
+ * available.
+ *
+ * Copyright (C) 2019 THL A29 Limited, a Tencent company. All rights reserved.
+ * If you have downloaded a copy of the TencentOS binary from Tencent, please
+ * note that the TencentOS binary is licensed under the BSD 3-Clause License.
+ *
+ * If you have downloaded a copy of the TencentOS source code from Tencent,
+ * please note that TencentOS source code is licensed under the BSD 3-Clause
+ * License, except for the third-party components listed below which are
+ * subject to different license terms. Your integration of TencentOS into your
+ * own projects may require compliance with the BSD 3-Clause License, as well
+ * as the other licenses applicable to the third-party components included
+ * within TencentOS.
+ *---------------------------------------------------------------------------*/
+
+#include "tos_elfloader.h"
+
+/* values for ELF32_R_TYPE(info) */
+#define R_ARM_ABS32             2
+#define R_ARM_THM_CALL          10
+#define R_ARM_GLOB_DAT          21
+#define R_ARM_JUMP_SLOT         22
+#define R_ARM_RELATIVE          23
+
+/*
+ - S (when used on its own) is the address of the symbol.
+ - A is the addend for the relocation.
+ - P is the address of the place being relocated (derived from r_offset).
+ - Pa is the adjusted address of the place being relocated, defined as (P & 0xFFFFFFFC).
+ - T is 1 if the target symbol S has type STT_FUNC and the symbol addresses a Thumb instruction; it is 0
+otherwise.
+ - B(S) is the addressing origin of the output segment defining the symbol S. The origin is not required to be the
+base address of the segment. This value must always be word-aligned.
+ - GOT_ORG is the addressing origin of the Global Offset Table (the indirection table for imported data
+addresses). This value must always be word-aligned. See §4.6.1.8, Proxy generating relocations.
+ - GOT(S) is the address of the GOT entry for the symbol S.
+*/
+
+// TODO: support more relocation type
+__KNL__ void elfloader_arch_relocate(uint32_t reloc_addr, int32_t load_bias, uint32_t addr, elf32_rela_t *rela, int is_rela)
+{
+    /* ATTENTION:
+        different reloc_addr calculation algorithm for relocatable object and shared object
+     */
+
+    switch (ELF32_R_TYPE(rela->r_info)) {
+        case R_ARM_GLOB_DAT:
+        case R_ARM_JUMP_SLOT:
+            /* (S + A) | T */
+            *(uint32_t *)reloc_addr = addr;
+            break;
+
+        case R_ARM_RELATIVE:
+            /* B(S) + A */
+            *(uint32_t *)reloc_addr += load_bias;
+            break;
+
+        case R_ARM_ABS32:
+            /* (S + A) | T */
+            *(uint32_t *)reloc_addr += addr;
+            break;
+
+        default:
+            printf("Unsupported Relocation Type: %d\n", ELF32_R_TYPE(rela->r_info));
+            break;
+    }
+}
+

components/elfloader/common/tos_elfloader_symtab.c

@@ -0,0 +1,32 @@
+/*----------------------------------------------------------------------------
+ * Tencent is pleased to support the open source community by making TencentOS
+ * available.
+ *
+ * Copyright (C) 2019 THL A29 Limited, a Tencent company. All rights reserved.
+ * If you have downloaded a copy of the TencentOS binary from Tencent, please
+ * note that the TencentOS binary is licensed under the BSD 3-Clause License.
+ *
+ * If you have downloaded a copy of the TencentOS source code from Tencent,
+ * please note that TencentOS source code is licensed under the BSD 3-Clause
+ * License, except for the third-party components listed below which are
+ * subject to different license terms. Your integration of TencentOS into your
+ * own projects may require compliance with the BSD 3-Clause License, as well
+ * as the other licenses applicable to the third-party components included
+ * within TencentOS.
+ *---------------------------------------------------------------------------*/
+
+#include "tos_elfloader.h"
+
+__KNL__ void *elfloader_symtab_lookup(char *name)
+{
+    const el_symbol_t *symbol;
+
+    for (symbol = &el_symbols[0]; symbol; ++symbol) {
+        if (strcmp(name, symbol->name) == 0) {
+            return symbol->value;
+        }
+    }
+
+    return K_NULL;
+}
+