Added preliminary support for execve(). Updates to clone, fork, exit, task handling.

It turned out we used one version of kmalloc for malloc() and another for kfree()!
Now fixed.
Added parent-child relationship to tasks. Need to polish handling CLONE_PARENT and THREAD.

tasks/mm0/include/lib/elf/elf.h

@@ -0,0 +1,61 @@
+/*
+ * Definitions for Executable Linking Format
+ * Based on Portable Formats Specification v1.1
+ *
+ * Copyright (C) 2008 Bahadir Balban
+ */
+
+#ifndef __ELF_H__
+#define __ELF_H__
+
+#include <l4/types.h>
+
+/* ELF identification indices */
+#define EI_MAG0		0
+#define EI_MAG1		1
+#define EI_MAG2		2
+#define EI_MAG3		3
+#define EI_CLASS	4
+#define EI_DATA		5
+#define EI_VERSION	6
+#define EI_PAD		7
+
+/* Size of ELF identification field */
+#define EI_NIDENT	16
+
+/* Values for ELF identification fields */
+#define ELFMAG0		0x7f
+#define ELFMAG1		'E'
+#define ELFMAG2		'L'
+#define ELFMAG3		'F'
+
+/* Values for the ELF Class field */
+#define ELFCLASSNONE	0
+#define ELFCLASS32	1
+#define ELFCLASS64	2
+
+/* Values for the ELF Data field */
+#define ELFDATANONE	0
+#define ELFDATA2LSB	1
+#define ELFDATA2MSB	2
+
+
+struct elf_header {
+	u8 	e_ident[EI_NIDENT];	/* ELF identification */
+	u16	e_type;			/* Object file type */
+	u16	e_machine;		/* Machine architecture */
+	u32	e_version;		/* Object file version */
+	u32	e_entry;		/* Virtual entry address */
+	u32	e_phoff;		/* Program header offset */
+	u32	e_shoff;		/* Section header offset */
+	u32	e_flags;		/* Processor specific flags */
+	u16	e_ehsize;		/* ELF header size */
+	u16	e_phentsize;		/* Program header entry size */
+	u16	e_phnum;		/* Number of program headers */
+	u16	e_shentsize;		/* Section header entry size */
+	u16	e_shnum;		/* Number of section headers */
+	u16	e_shstrndx;		/* Shtable index for strings */
+} __attribute__((__packed__));
+
+
+#endif /* __ELF_H__ */

tasks/mm0/include/lib/elf/elfprg.h

@@ -0,0 +1,35 @@
+/*
+ * Definitions for ELF program headers
+ * Based on Portable Formats Specification v1.1
+ *
+ * Copyright (C) 2008 Bahadir Balban
+ */
+#ifndef __ELFPRG_H__
+#define __ELFPRG_H__
+
+#include <l4/types.h>
+
+struct elf_program_header {
+	u32	p_type;		/* Type of segment */
+	u32	p_offset;	/* Segment file offset */
+	u32	p_vaddr;	/* Virtual start address */
+	u32	p_paddr;	/* Physical start address */
+	u32	p_filesz;	/* Size in stored file */
+	u32	p_memsz;	/* Size in memory image */
+	u32	p_flags;	/* Segment attributes */
+	u32	p_align;	/* Alignment requirement */
+} __attribute__((__packed__));
+
+/* Program segment type definitions */
+#define PT_NULL				0
+#define PT_LOAD				1
+#define PT_DYNAMIC			2
+#define PT_INTERP			3
+#define PT_NOTE				4
+#define PT_SHLIB			5
+#define PT_PHDR				6
+#define PT_LOPROC			0x70000000
+#define PT_HIPROC			0x7FFFFFFF
+
+
+#endif /* __ELFPRG_H__ */

tasks/mm0/include/lib/elf/elfsect.h

@@ -0,0 +1,60 @@
+/*
+ * Definitions for ELF Sections
+ * Based on Portable Formats Specification v1.1
+ *
+ * Copyright (C) 2008 Bahadir Balban
+ */
+
+#ifndef __ELFSECT_H__
+#define __ELFSECT_H__
+
+#include <l4/types.h>
+
+/* Special section indices */
+#define SHN_UNDEF			0
+#define SHN_LORESERVE			0xFF00
+#define SHN_LOPROC			0xFF00
+#define SHN_HIPROC			0xFF1F
+#define SHN_ABS				0xFFF1
+#define SHN_COMMON			0xFFF2
+#define SHN_HIRESERVE			0xFFFF
+
+
+struct elf_section_header {
+	u32	sh_name;	/* Index to section header str table for name */
+	u32	sh_type;	/* Categorises section's semantics */
+	u32	sh_flags;	/* Flags that define various attributes */
+	u32	sh_addr;	/* Virtual address for section */
+	u32	sh_offset;	/* Offset to contents from file beginning */
+	u32	sh_size;	/* Size of section (note SHT_NOBITS) */
+	u32	sh_link;
+	u32	sh_info;	/* Extra section info */
+	u32	sh_addralign;	/* Section alignment in power of 2 */
+	u32	sh_entsize;	/* Size of each entry if fixed */
+} __attribute__((__packed__));
+
+/* Section type codes */
+#define SHT_NULL			0	/* Inactive */
+#define SHT_PROGBITS			1	/* Program contents */
+#define SHT_SYMTAB			2	/* Symbol table */
+#define SHT_STRTAB			3	/* String table */
+#define SHT_RELA			4	/* Relocation entries */
+#define SHT_HASH			5	/* Symbol hash table */
+#define SHT_DYNAMIC			6	/* Dynamic linking info */
+#define SHT_NOTE			7	/* Optional, additional info */
+#define SHT_NOBITS			8	/* Does not occupy file space */
+#define SHT_REL				9	/* Relocation entries */
+#define SHT_SHLIB			10	/* Reserved */
+#define SHT_DYNSYM			11	/* Symbols for dynamic linking */
+#define SHT_LOPROC		0x70000000	/* Reserved for processors */
+#define SHT_HIPROC		0x7FFFFFFF	/* Reserved for processors */
+#define SHT_LOUSER		0x80000000	/* Reserved for user progs */
+#define SHT_HIUSER		0xFFFFFFFF	/* Reserved for user progs */
+
+/* Section attribute flags */
+#define SHF_WRITE		(1 << 0)	/* Writeable */
+#define SHF_ALLOC		(1 << 1)	/* Occupies actual memory */
+#define SHF_EXECINSTR		(1 << 2)	/* Executable */
+#define SHF_MASCPROC		0xF0000000	/* Reserved for processors */
+
+#endif /* __ELFSECT_H__ */

tasks/mm0/include/lib/elf/elfsym.h

@@ -0,0 +1,59 @@
+/*
+ * Definitions for ELF Symbol tables, symbols
+ * Based on Portable Formats Specification v1.1
+ *
+ * Copyright (C) 2008 Bahadir Balban
+ */
+#ifndef __ELFSYM_H__
+#define __ELFSYM_H__
+
+#include <l4/types.h>
+
+struct elf_symbol_entry {
+	u32	st_name;	/* Index into string table */
+	u32	st_value;	/* Symbol value; address, aboslute etc. */
+	u32	st_size;	/* Number of bytes contained in object */
+	u8	st_info;	/* Type and binding attributes */
+	u8	st_other;	/* Unused, 0 */
+	u16	st_shndx;	/* Section header index associated with entry */
+} __attribute__((__packed__));
+
+/* To manipulate binding and type attributes on st_info field */
+#define ELF32_ST_BIND(i)	((i) >> 4)
+#define ELF32_ST_TYPE(i)	((i) & 0xF)
+#define ELF32_ST_INFO(b, t)	(((b) << 4) + ((t) & 0xF))
+
+/* Symbol binding codes */
+#define STB_LOCAL		0
+#define STB_GLOBAL		1
+#define STB_WEAK		2
+#define STB_LOPROC		13
+#define STB_HIPROC		15
+
+/* Symbol types */
+#define STT_NOTYPE		0
+#define STT_OBJECT		1
+#define STT_FUNC		2
+#define STT_SECTION		3
+#define STT_FILE		4
+#define STT_LOPROC		13
+#define STT_HIPROC		15
+
+/* Relocation structures */
+struct elf_rel {
+	u32	r_offset;
+	u32	r_info;
+} __attribute__((__packed__));
+
+struct elf_rela {
+	u32	r_offset;
+	u32	r_info;
+	s32	r_addend;
+} __attribute__((__packed__));
+
+/* Macros to manipulate r_info field */
+#define ELF32_R_SYM(i)			((i) >> 8)
+#define ELF32_R_TYPE(i)			((u8)(i))
+#define ELF32_R_INFO(s,t)		(((s) << 8) + (u8)(t))
+
+#endif /* __ELFSYM_H__ */