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-rw-r--r--src/stem/Makefile3
-rw-r--r--src/stem/linker/elf.c31
-rw-r--r--src/stem/linker/elf.h63
-rw-r--r--src/stem/stem.map14
4 files changed, 108 insertions, 3 deletions
diff --git a/src/stem/Makefile b/src/stem/Makefile
index d212216..41b5368 100644
--- a/src/stem/Makefile
+++ b/src/stem/Makefile
@@ -12,7 +12,8 @@ OBJECTS = core/loader_.o core/kmain.o core/sys.o \
core/monitor.o task/timer.o \
task/idt.o task/idt_.o task/task.o task/task_.o task/syscall.o \
lib/stdlib.o lib/bitset.o \
- mem/mem.o mem/paging.o mem/gdt.o mem/heap.o mem/seg.o
+ mem/mem.o mem/paging.o mem/gdt.o mem/heap.o mem/seg.o \
+ linker/elf.o
OUT = stem.elf
all: $(OBJECTS)
diff --git a/src/stem/linker/elf.c b/src/stem/linker/elf.c
new file mode 100644
index 0000000..62030ee
--- /dev/null
+++ b/src/stem/linker/elf.c
@@ -0,0 +1,31 @@
+#include "elf.h"
+#include <mem/paging.h>
+#include <mem/seg.h>
+#include <stdlib.h>
+
+int elf_check(uint8_t *data) {
+ struct elf_ehdr *h = (struct elf_ehdr*)data;
+ if (h->e_ident[0] == 0x7F && h->e_ident[1] == 'E' && h->e_ident[2] == 'L' && h->e_ident[3] == 'F') return 0;
+ return 1;
+}
+
+thread_entry elf_load(uint8_t *data, struct process* process) {
+ struct elf_ehdr *ehdr = (struct elf_ehdr*)data;
+ struct elf_phdr *phdr;
+ int i;
+ if (elf_check(data)) return 0;
+
+ pagedir_switch(process->pagedir);
+
+ phdr = (struct elf_phdr*)((uint8_t*)(data + ehdr->e_phoff));
+ for (i = 0; i < ehdr->e_phnum; i++) {
+ if (phdr[i].p_type == PT_LOAD) {
+ seg_map(simpleseg_make(phdr[i].p_vaddr, phdr[i].p_memsz, (phdr[i].p_flags & PF_W) != 0), process->pagedir);
+ memcpy((uint8_t*)phdr[i].p_vaddr, data + phdr[i].p_offset, phdr[i].p_filesz);
+ if (phdr[i].p_memsz > phdr[i].p_filesz) {
+ memset((uint8_t*)phdr[i].p_vaddr + phdr[i].p_memsz, 0, phdr[i].p_memsz - phdr[i].p_filesz);
+ }
+ }
+ }
+ return (thread_entry)ehdr->e_entry;
+}
diff --git a/src/stem/linker/elf.h b/src/stem/linker/elf.h
new file mode 100644
index 0000000..f84bb62
--- /dev/null
+++ b/src/stem/linker/elf.h
@@ -0,0 +1,63 @@
+#ifndef DEF_ELF_H
+#define DEF_ELF_H
+
+#include <types.h>
+#include <task/task.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)
+
+struct elf_ehdr {
+ 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 */
+};
+
+struct elf_phdr {
+ 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;
+};
+
+struct phdr {
+ struct elf_phdr h;
+ uint8_t* data;
+};
+
+int elf_check(uint8_t *data); //0 if ok, 1 if not a valid ELF
+thread_entry elf_load(uint8_t *data, struct process* process); //Load an ELF to a process, return entry point
+struct process* elf_exec(uint8_t *data); //Creates a new process and a thread for running ELF file
+
+#endif
diff --git a/src/stem/stem.map b/src/stem/stem.map
index c35b1ee..a919c01 100644
--- a/src/stem/stem.map
+++ b/src/stem/stem.map
@@ -26,7 +26,7 @@ Linker script and memory map
0x00100000 loader
0xe010003a . = (. + 0xe0000000)
-.text 0xe0100040 0x3395 load address 0x00100040
+.text 0xe0100040 0x355a load address 0x00100040
*(.text)
.text 0xe0100040 0x25 core/loader_.o
*fill* 0xe0100065 0x3 00
@@ -178,8 +178,12 @@ Linker script and memory map
0xe01032e8 simpleseg_unmap
0xe010333b simpleseg_handleFault
0xe01033d0 simpleseg_delete
+ *fill* 0xe01033d5 0x3 00
+ .text 0xe01033d8 0x1c2 linker/elf.o
+ 0xe01033d8 elf_check
+ 0xe010341d elf_load
-.iplt 0xe01033d8 0x0 load address 0x001033d5
+.iplt 0xe010359c 0x0 load address 0x0010359a
.iplt 0x00000000 0x0 core/loader_.o
.rodata 0xe0104000 0x395 load address 0x00104000
@@ -216,6 +220,7 @@ Linker script and memory map
.data 0xe0105024 0x0 mem/gdt.o
.data 0xe0105024 0x0 mem/heap.o
.data 0xe0105024 0x0 mem/seg.o
+ .data 0xe0105024 0x0 linker/elf.o
.igot.plt 0xe0105024 0x0 load address 0x00105024
.igot.plt 0x00000000 0x0 core/loader_.o
@@ -258,6 +263,7 @@ Linker script and memory map
*fill* 0xe01159ae 0x2 00
.bss 0xe01159b0 0x0 mem/heap.o
.bss 0xe01159b0 0x0 mem/seg.o
+ .bss 0xe01159b0 0x0 linker/elf.o
0xe01159b0 ebss = .
0xe01159b0 end = .
0xe01159b0 _end = .
@@ -279,6 +285,7 @@ LOAD mem/paging.o
LOAD mem/gdt.o
LOAD mem/heap.o
LOAD mem/seg.o
+LOAD linker/elf.o
OUTPUT(stem.elf elf32-i386)
.comment 0x00000000 0x11
@@ -297,6 +304,7 @@ OUTPUT(stem.elf elf32-i386)
.comment 0x00000000 0x12 mem/gdt.o
.comment 0x00000000 0x12 mem/heap.o
.comment 0x00000000 0x12 mem/seg.o
+ .comment 0x00000000 0x12 linker/elf.o
.note.GNU-stack
0x00000000 0x0
@@ -328,3 +336,5 @@ OUTPUT(stem.elf elf32-i386)
0x00000000 0x0 mem/heap.o
.note.GNU-stack
0x00000000 0x0 mem/seg.o
+ .note.GNU-stack
+ 0x00000000 0x0 linker/elf.o
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-23 04:30:16 +0000