sbtools: move internal elf definition to elf.c, implement elf reading

sbtoelf: generate a correct section name for undef and string table sections
elftosb: static'ify functions, add cmd file to sb file conversion

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@29738 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 235 insertions, 5 deletions

diff --git a/utils/sbtools/elf.c b/utils/sbtools/elf.c
index f146bcc111..4b95025d8f 100644
--- a/utils/sbtools/elf.c
+++ b/utils/sbtools/elf.c
@@ -1,5 +1,135 @@
 #include "elf.h"
 
+/**
+ * Definitions
+ *   taken from elf.h linux header
+ *   based on ELF specification
+ *   based on ARM ELF specification
+ */
+typedef uint16_t Elf32_Half;
+
+typedef uint32_t Elf32_Word;
+typedef int32_t  Elf32_Sword;
+typedef uint32_t Elf32_Addr;
+typedef uint32_t Elf32_Off;
+typedef uint16_t Elf32_Section;
+
+#define EI_NIDENT   16
+
+typedef struct
+{
+    unsigned char   e_ident[EI_NIDENT]; /* Magic number and other info */
+    Elf32_Half      e_type; /* Object file type */
+    Elf32_Half      e_machine; /* Architecture */
+    Elf32_Word      e_version; /* Object file version */
+    Elf32_Addr      e_entry; /* Entry point virtual address */
+    Elf32_Off       e_phoff; /* Program header table file offset */
+    Elf32_Off       e_shoff; /* Section header table file offset */
+    Elf32_Word      e_flags; /* Processor-specific flags */
+    Elf32_Half      e_ehsize; /* ELF header size in bytes */
+    Elf32_Half      e_phentsize; /* Program header table entry size */
+    Elf32_Half      e_phnum; /* Program header table entry count */
+    Elf32_Half      e_shentsize; /* Section header table entry size */
+    Elf32_Half      e_shnum; /* Section header table entry count */
+    Elf32_Half      e_shstrndx; /* Section header string table index */
+}Elf32_Ehdr;
+
+#define EI_MAG0     0 /* File identification byte 0 index */
+#define ELFMAG0     0x7f /* Magic number byte 0 */
+
+#define EI_MAG1     1 /* File identification byte 1 index */
+#define ELFMAG1     'E' /* Magic number byte 1 */
+
+#define EI_MAG2     2 /* File identification byte 2 index */
+#define ELFMAG2     'L' /* Magic number byte 2 */
+
+#define EI_MAG3     3 /* File identification byte 3 index */
+#define ELFMAG3     'F' /* Magic number byte 3 */
+
+#define EI_CLASS    4 /* File class byte index */
+#define ELFCLASS32  1 /* 32-bit objects */
+
+#define EI_DATA     5 /* Data encoding byte index */
+#define ELFDATA2LSB 1 /* 2's complement, little endian */
+
+#define EI_VERSION  6 /* File version byte index, Value must be EV_CURRENT */
+
+#define EI_OSABI    7 /* OS ABI identification */
+#define ELFOSABI_NONE       0 /* UNIX System V ABI */
+#define ELFOSABI_ARM_AEABI  64 /* ARM EABI */
+#define ELFOSABI_ARM        97 /* ARM */
+
+#define EI_ABIVERSION   8 /* ABI version */
+
+#define EI_PAD      9 /* Byte index of padding bytes */
+
+#define ET_EXEC     2 /* Executable file */
+
+#define EM_ARM      40 /* ARM */
+
+#define EV_CURRENT  1 /* Current version */
+
+#define EF_ARM_HASENTRY     0x00000002
+
+#define SHN_UNDEF   0 /* Undefined section */
+
+typedef struct
+{
+    Elf32_Word  sh_name; /* Section name (string tbl index) */
+    Elf32_Word  sh_type; /* Section type */
+    Elf32_Word  sh_flags; /* Section flags */
+    Elf32_Addr  sh_addr; /* Section virtual addr at execution */
+    Elf32_Off   sh_offset; /* Section file offset */
+    Elf32_Word  sh_size; /* Section size in bytes */
+    Elf32_Word  sh_link; /* Link to another section */
+    Elf32_Word  sh_info; /* Additional section information */
+    Elf32_Word  sh_addralign; /* Section alignment */
+    Elf32_Word  sh_entsize; /* Entry size if section holds table */
+}Elf32_Shdr;
+
+#define SHT_NULL            0 /* Section header table entry unused */
+#define SHT_PROGBITS        1 /* Program data */
+#define SHT_SYMTAB          2 /* Symbol table */
+#define SHT_STRTAB          3 /* String table */
+#define SHT_RELA            4 /* Relocation entries with addends */
+#define SHT_HASH            5 /* Symbol hash table */
+#define SHT_DYNAMIC         6 /* Dynamic linking information */
+#define SHT_NOTE            7 /* Notes */
+#define SHT_NOBITS          8 /* Program space with no data (bss) */
+#define SHT_REL             9 /* Relocation entries, no addends */
+#define SHT_SHLIB           10 /* Reserved */
+#define SHT_DYNSYM          11 /* Dynamic linker symbol table */
+#define SHT_INIT_ARRAY      14 /* Array of constructors */
+#define SHT_FINI_ARRAY      15 /* Array of destructors */
+#define SHT_PREINIT_ARRAY   16 /* Array of pre-constructors */
+#define SHT_GROUP           17 /* Section group */
+#define SHT_SYMTAB_SHNDX    18 /* Extended section indeces */
+#define SHT_NUM             19 /* Number of defined types.  */
+
+#define SHF_WRITE       (1 << 0) /* Writable */
+#define SHF_ALLOC       (1 << 1) /* Occupies memory during execution */
+#define SHF_EXECINSTR   (1 << 2) /* Executable */
+#define SHF_MERGE       (1 << 4) /* Might be merged */
+#define SHF_STRINGS     (1 << 5) /* Contains nul-terminated strings */
+
+typedef struct
+{
+    Elf32_Word  p_type; /* Segment type */
+    Elf32_Off   p_offset; /* Segment file offset */
+    Elf32_Addr  p_vaddr; /* Segment virtual address */
+    Elf32_Addr  p_paddr; /* Segment physical address */
+    Elf32_Word  p_filesz; /* Segment size in file */
+    Elf32_Word  p_memsz; /* Segment size in memory */
+    Elf32_Word  p_flags; /* Segment flags */
+    Elf32_Word  p_align; /* Segment alignment */
+}Elf32_Phdr;
+
+#define PT_LOAD     1 /* Loadable program segment */
+
+#define PF_X    (1 << 0) /* Segment is executable */
+#define PF_W    (1 << 1) /* Segment is writable */
+#define PF_R    (1 << 2) /* Segment is readable */
+
 void elf_init(struct elf_params_t *params)
 {
     params->has_start_addr = false;
@@ -54,7 +184,7 @@ void elf_add_fill_section(struct elf_params_t *params,
     sec->pattern = pattern;
 }
 
-void elf_output(struct elf_params_t *params, elf_write_fn_t write, void *user)
+void elf_write_file(struct elf_params_t *params, elf_write_fn_t write, void *user)
 {
     Elf32_Ehdr ehdr;
     uint32_t phnum = 0;
@@ -64,9 +194,11 @@ void elf_output(struct elf_params_t *params, elf_write_fn_t write, void *user)
     Elf32_Shdr shdr;
     memset(&ehdr, 0, EI_NIDENT);
 
-    uint32_t bss_strtbl = 0;
+    uint32_t bss_strtbl = 1;
     uint32_t text_strtbl = bss_strtbl + strlen(".bss") + 1;
-    uint32_t strtbl_size = text_strtbl + strlen(".text") + 1;
+    uint32_t shstrtab_strtbl = text_strtbl + strlen(".text") + 1;
+    uint32_t strtbl_size = shstrtab_strtbl + strlen(".shstrtab") + 1;
+    
 
     while(sec)
     {
@@ -182,7 +314,7 @@ void elf_output(struct elf_params_t *params, elf_write_fn_t write, void *user)
     }
 
     {
-        shdr.sh_name = bss_strtbl;
+        shdr.sh_name = shstrtab_strtbl;
         shdr.sh_type = SHT_STRTAB;
         shdr.sh_flags = 0;
         shdr.sh_addr = 0;
@@ -206,7 +338,86 @@ void elf_output(struct elf_params_t *params, elf_write_fn_t write, void *user)
         sec = sec->next;
     }
 
-    write(user, strtbl_offset + data_offset, ".bss\0.text\0", strtbl_size);
+    write(user, strtbl_offset + data_offset, "\0.bss\0.text\0.shstrtab\0", strtbl_size);
+}
+
+bool elf_read_file(struct elf_params_t *params, elf_read_fn_t read,
+    elf_printf_fn_t printf, void *user)
+{
+    #define error_printf(...) ({printf(user, true, __VA_ARGS__); return false;})
+    /* read header */
+    Elf32_Ehdr ehdr;
+    if(!read(user, 0, &ehdr, sizeof(ehdr)))
+    {
+        printf(user, true, "error reading elf header\n");
+        return false;
+    }
+    /* basic checks */
+    if(ehdr.e_ident[EI_MAG0] != ELFMAG0 || ehdr.e_ident[EI_MAG1] != ELFMAG1 ||
+            ehdr.e_ident[EI_MAG2] != ELFMAG2 || ehdr.e_ident[EI_MAG3] != ELFMAG3)
+        error_printf("invalid elf header\n");
+    if(ehdr.e_ident[EI_CLASS] != ELFCLASS32)
+        error_printf("invalid elf class: must be a 32-bit object\n");
+    if(ehdr.e_ident[EI_DATA] != ELFDATA2LSB)
+        error_printf("invalid elf data encoding: must be 32-bit lsb\n");
+    if(ehdr.e_ident[EI_VERSION] != EV_CURRENT)
+        error_printf("invalid elf version");
+    if(ehdr.e_type != ET_EXEC)
+        error_printf("invalid elf file: must be an executable file\n");
+    if(ehdr.e_machine != EM_ARM)
+        error_printf("invalid elf file: must target an arm machine\n");
+    if(ehdr.e_ehsize != sizeof(ehdr))
+        error_printf("invalid elf file: size header mismatch\n");
+    if(ehdr.e_phentsize != sizeof(Elf32_Phdr))
+        error_printf("invalid elf file: program header size mismatch\n");
+    if(ehdr.e_shentsize != sizeof(Elf32_Shdr))
+        error_printf("invalid elf file: section header size mismatch\n");
+    if(ehdr.e_flags & EF_ARM_HASENTRY)
+        elf_set_start_addr(params, ehdr.e_entry);
+
+    char *strtab = NULL;
+    {
+        Elf32_Shdr shstrtab;
+        if(read(user, ehdr.e_shoff + ehdr.e_shstrndx * ehdr.e_shentsize,
+                &shstrtab, sizeof(shstrtab)))
+        {
+            strtab = xmalloc(shstrtab.sh_size);
+            if(!read(user, shstrtab.sh_offset, strtab, shstrtab.sh_size))
+            {
+                free(strtab);
+                strtab = NULL;
+            }
+        }
+    }
+    /* run through sections */
+    printf(user, false, "ELF file:\n");
+    for(int i = 1; i< ehdr.e_shnum; i++)
+    {
+        uint32_t off = ehdr.e_shoff + i * ehdr.e_shentsize;
+        Elf32_Shdr shdr;
+        memset(&shdr, 0, sizeof(shdr));
+        if(!read(user, off, &shdr, sizeof(shdr)))
+            error_printf("error reading elf section header");
+
+        if(shdr.sh_type == SHT_PROGBITS && shdr.sh_flags & SHF_ALLOC)
+        {
+            void *data = xmalloc(shdr.sh_size);
+            if(!read(user, shdr.sh_offset, data, shdr.sh_size))
+                error_printf("error read self section data");
+            elf_add_load_section(params, shdr.sh_addr, shdr.sh_size, data);
+
+            printf(user, false, "create load segment for %s\n", &strtab[shdr.sh_name]);
+        }
+        else if(shdr.sh_type == SHT_NOBITS && shdr.sh_flags & SHF_ALLOC)
+        {
+            elf_add_fill_section(params, shdr.sh_addr, shdr.sh_size, 0);
+            printf(user, false, "create fill segment for %s\n", &strtab[shdr.sh_name]);
+        }
+        else
+            printf(user, false, "filter out %s\n", &strtab[shdr.sh_name], shdr.sh_type);
+        
+    }
+    return true;
 }
 
 bool elf_is_empty(struct elf_params_t *params)
@@ -220,6 +431,25 @@ void elf_set_start_addr(struct elf_params_t *params, uint32_t addr)
     params->start_addr = addr;
 }
 
+bool elf_get_start_addr(struct elf_params_t *params, uint32_t *addr)
+{
+    if(params->has_start_addr && addr != NULL)
+        *addr = params->start_addr;
+    return params->has_start_addr;
+}
+
+int elf_get_nr_sections(struct elf_params_t *params)
+{
+    int nr = 0;
+    struct elf_section_t *sec = params->first_section;
+    while(sec)
+    {
+        nr++;
+        sec = sec->next;
+    }
+    return nr;
+}
+
 void elf_release(struct elf_params_t *params)
 {
     struct elf_section_t *sec, *next_sec;