Merge pull request #36 from spicyjpeg/dynlink

Dynamic linker, gp-relative addressing, ldscripts and more

1 files changed, 138 insertions, 0 deletions

diff --git a/libpsn00b/include/elf.h b/libpsn00b/include/elf.h
new file mode 100644
index 0000000..b4c4408
--- /dev/null
+++ b/libpsn00b/include/elf.h
@@ -0,0 +1,138 @@
+/*
+ * PSn00bSDK dynamic linker
+ * (C) 2021 spicyjpeg - MPL licensed
+ *
+ * This file is used internally by the dynamic linker to parse the "header"
+ * (.dynamic and .dynsym sections) of dynamically-linked libraries built with
+ * the provided linker script. Most of it is copied from the standard Unix
+ * elf.h header, with the only changes being removed typedefs and #defines
+ * converted to enums.
+ */
+
+#ifndef __ELF_H
+#define __ELF_H 
+
+#include <sys/types.h>
+
+typedef enum {
+	DT_NULL		= 0,		/* Marks end of dynamic section */
+	DT_NEEDED	= 1,		/* Name of needed library */
+	DT_PLTRELSZ	= 2,		/* Size in bytes of PLT relocs */
+	DT_PLTGOT	= 3,		/* Processor defined value */
+	DT_HASH		= 4,		/* Address of symbol hash table */
+	DT_STRTAB	= 5,		/* Address of string table */
+	DT_SYMTAB	= 6,		/* Address of symbol table */
+	DT_RELA		= 7,		/* Address of Rela relocs */
+	DT_RELASZ	= 8,		/* Total size of Rela relocs */
+	DT_RELAENT	= 9,		/* Size of one Rela reloc */
+	DT_STRSZ	= 10,		/* Size of string table */
+	DT_SYMENT	= 11,		/* Size of one symbol table entry */
+	DT_INIT		= 12,		/* Address of init function */
+	DT_FINI		= 13,		/* Address of termination function */
+	DT_SONAME	= 14,		/* Name of shared object */
+	DT_RPATH	= 15,		/* Library search path (deprecated) */
+	DT_SYMBOLIC	= 16,		/* Start symbol search here */
+	DT_REL		= 17,		/* Address of Rel relocs */
+	DT_RELSZ	= 18,		/* Total size of Rel relocs */
+	DT_RELENT	= 19,		/* Size of one Rel reloc */
+	DT_PLTREL	= 20,		/* Type of reloc in PLT */
+	DT_DEBUG	= 21,		/* For debugging; unspecified */
+	DT_TEXTREL	= 22,		/* Reloc might modify .text */
+	DT_JMPREL	= 23,		/* Address of PLT relocs */
+	DT_BIND_NOW	= 24,		/* Process relocations of object */
+	DT_INIT_ARRAY	= 25,	/* Array with addresses of init fct */
+	DT_FINI_ARRAY	= 26,	/* Array with addresses of fini fct */
+	DT_INIT_ARRAYSZ	= 27,	/* Size in bytes of DT_INIT_ARRAY */
+	DT_FINI_ARRAYSZ	= 28,	/* Size in bytes of DT_FINI_ARRAY */
+	DT_RUNPATH	= 29,		/* Library search path */
+	DT_FLAGS	= 30,		/* Flags for the object being loaded */
+	DT_ENCODING	= 32,		/* Start of encoded range */
+	DT_PREINIT_ARRAY	= 32,	/* Array with addresses of preinit fct*/
+	DT_PREINIT_ARRAYSZ	= 33,	/* size in bytes of DT_PREINIT_ARRAY */
+	DT_SYMTAB_SHNDX		= 34,	/* Address of SYMTAB_SHNDX section */
+	DT_NUM		= 35,			/* Number used */
+	DT_LOOS		= 0x6000000d,	/* Start of OS-specific */
+	DT_HIOS		= 0x6ffff000,	/* End of OS-specific */
+	DT_LOPROC	= 0x70000000,	/* Start of processor-specific */
+	DT_HIPROC	= 0x7fffffff,	/* End of processor-specific */
+
+	DT_MIPS_RLD_VERSION		= 0x70000001,
+	DT_MIPS_FLAGS			= 0x70000005,
+	DT_MIPS_BASE_ADDRESS	= 0x70000006,
+	DT_MIPS_LOCAL_GOTNO		= 0x7000000a,
+	DT_MIPS_SYMTABNO		= 0x70000011,
+	DT_MIPS_UNREFEXTNO		= 0x70000012,
+	DT_MIPS_GOTSYM			= 0x70000013,
+	DT_MIPS_HIPAGENO		= 0x70000014
+} Elf32_d_tag;
+
+typedef enum {
+	RHF_NONE		= 0,	/* No flags */
+	RHF_QUICKSTART	= 1,	/* Use quickstart */
+	RHF_NOTPOT		= 2,	/* Hash size not power of 2 */
+	RHF_NO_LIBRARY_REPLACEMENT	= 4 /* Ignore LD_LIBRARY_PATH */
+} Elf32_d_MIPS_FLAGS;
+
+typedef struct {
+	Elf32_d_tag	d_tag;			/* Dynamic entry type */
+	union {
+		uint32_t	d_val;		/* Integer value */
+		void		*d_ptr;		/* Address value */
+	} d_un;
+} Elf32_Dyn;
+
+typedef struct {
+	uint32_t	st_name;		/* Symbol name (string tbl index) */
+	void		*st_value;		/* Symbol value */
+	size_t		st_size;		/* Symbol size */
+	uint8_t		st_info;		/* Symbol type and binding */
+	uint8_t		st_other;		/* Symbol visibility */
+	uint16_t	st_shndx;		/* Section index */
+} Elf32_Sym;
+
+#define ELF32_ST_BIND(val)			((Elf32_st_bind) (((uint8_t) (val)) >> 4))
+#define ELF32_ST_TYPE(val)			((Elf32_st_type) ((val) & 0xf))
+#define ELF32_ST_INFO(bind, type)	((((uint8_t) (bind)) << 4) + (((uint8_t) (type)) & 0xf))
+
+typedef enum {
+	STB_LOCAL	= 0,		/* Local symbol */
+	STB_GLOBAL	= 1,		/* Global symbol */
+	STB_WEAK	= 2,		/* Weak symbol */
+	STB_NUM		= 3,		/* Number of defined types.  */
+	STB_LOOS	= 10,		/* Start of OS-specific */
+	STB_GNU_UNIQUE	= 10,	/* Unique symbol.  */
+	STB_HIOS	= 12,		/* End of OS-specific */
+	STB_LOPROC	= 13,		/* Start of processor-specific */
+	STB_HIPROC	= 15		/* End of processor-specific */
+} Elf32_st_bind;
+
+typedef enum {
+	STT_NOTYPE	= 0,		/* Symbol type is unspecified */
+	STT_OBJECT	= 1,		/* Symbol is a data object */
+	STT_FUNC	= 2,		/* Symbol is a code object */
+	STT_SECTION	= 3,		/* Symbol associated with a section */
+	STT_FILE	= 4,		/* Symbol's name is file name */
+	STT_COMMON	= 5,		/* Symbol is a common data object */
+	STT_TLS		= 6,		/* Symbol is thread-local data object*/
+	STT_NUM		= 7,		/* Number of defined types.  */
+	STT_LOOS	= 10,		/* Start of OS-specific */
+	STT_GNU_IFUNC	= 10,	/* Symbol is indirect code object */
+	STT_HIOS	= 12,		/* End of OS-specific */
+	STT_LOPROC	= 13,		/* Start of processor-specific */
+	STT_HIPROC	= 15		/* End of processor-specific */
+} Elf32_st_type;
+
+// If you need to add more constants, you may use the following Python snippet
+// to quickly convert #defines to enums:
+/*
+import re
+t = """<paste #defines here>"""
+t = re.sub(
+	r"(0x[0-9a-f]+|0b[01]+|[0-9]+)",
+	lambda m: f"= {m.group(1)},",
+	t.replace("#define ",  "\t").replace("#define\t", "\t")
+)
+print("typedef enum {\n" + t + "\n} NAME;")
+*/
+
+#endif