Implement ELF loading ; arrange so that user processes run.

2 files changed, 64 insertions, 1 deletions

diff --git a/src/kernel/include/elf.h b/src/kernel/include/elf.h
new file mode 100644
index 0000000..6e0c7cb
--- /dev/null
+++ b/src/kernel/include/elf.h
@@ -0,0 +1,59 @@
+#pragma once
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include <vfs.h>
+#include <process.h>
+
+/* elf_phdr_t :: p_type : program header entries types */
+#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
+ 
+/* elf_phdr_t :: p_flags : program header entries flags */
+#define PF_X	(1 << 0)
+#define PF_W	(1 << 1)
+#define PF_R	(1 << 2)
+
+typedef struct {
+	uint8_t e_ident[16];      /* ELF identification */
+	uint16_t e_type;             /* 2 (exec file) */
+	uint16_t e_machine;          /* 3 (intel architecture) */
+	uint32_t e_version;          /* 1 */
+	uint32_t e_entry;            /* starting point */
+	uint32_t e_phoff;            /* program header table offset */
+	uint32_t e_shoff;            /* section header table offset */
+	uint32_t e_flags;            /* various flags */
+	uint16_t e_ehsize;           /* ELF header (this) size */
+
+	uint16_t e_phentsize;        /* program header table entry size */
+	uint16_t e_phnum;            /* number of entries */
+
+	uint16_t e_shentsize;        /* section header table entry size */
+	uint16_t e_shnum;            /* number of entries */
+
+	uint16_t e_shstrndx;         /* index of the section name string table */
+} elf_ehdr_t;
+ 
+typedef struct {
+	uint32_t p_type;             /* type of segment */
+	uint32_t p_offset;
+	uint32_t p_vaddr;
+	uint32_t p_paddr;
+	uint32_t p_filesz;
+	uint32_t p_memsz;
+	uint32_t p_flags;
+	uint32_t p_align;
+} elf_phdr_t;
+ 
+bool is_elf(fs_handle_t *f);
+proc_entry_t elf_load(fs_handle_t *f, process_t *process);	//Load an ELF to a process, return entry point
+
+/* vim: set ts=4 sw=4 tw=0 noet :*/
diff --git a/src/kernel/include/process.h b/src/kernel/include/process.h
index d67ede6..661aaa6 100644
--- a/src/kernel/include/process.h
+++ b/src/kernel/include/process.h
@@ -27,12 +27,16 @@
 struct process;
 typedef struct process process_t;
 
+typedef void* proc_entry_t;
+
 process_t *current_process();
 
 process_t *new_process(process_t *parent);
 // void delete_process(process_t *p);	// TODO define semantics for freeing stuff
 
-bool start_process(process_t *p, void* entry);	// maps a region for user stack
+pagedir_t *proc_pagedir(process_t *p);
+
+bool start_process(process_t *p, proc_entry_t entry);	// maps a region for user stack
 
 bool proc_add_fs(process_t *p, fs_t *fs, const char* name);
 fs_t *proc_find_fs(process_t *p, const char* name);