elf: add null section

1 files changed, 27 insertions, 50 deletions

diff --git a/bfc.S b/bfc.S
index 134d2d1..f20d3bf 100644
--- a/bfc.S
+++ b/bfc.S
@@ -11,7 +11,14 @@
 .section translations, "a"
 
 t_init:
-	mov $0x3001b0, %rbx
+	mov $SYS_BRK, %rax
+	mov $0x0, %rdi
+	syscall
+	add $0x400, %rax
+	mov %rax, %rbx
+	mov %rax, %rdi
+	mov $SYS_BRK, %rax
+	syscall
 t_init_end:
 
 t_exit:
@@ -73,63 +80,41 @@ c_elf_header:
 	.byte 0x1        # ELFv1
 	.byte 0x0        # System V ABI
 	.quad 0x0        #
-	.hword 0x02      # Executable
+	.hword 0x2      # Executable
 	.hword 0x3e      # AMD x86-64
 	.int 0x1         # ELFv1
-	.quad 0x4005b0   # Entry
+	.quad 0x400148   # Entry
 	.quad 0x40       # Program Header Offset
-	.quad 0xb0       # TODO: Section Header Offset
+	.quad 0x78       # TODO: Section Header Offset
 	.int 0x0         #
 	.hword 0x40      # ELF Header Size
 	.hword 0x38      # Program Header Table Entry Size
-	.hword 0x2       # TODO: Number Of Entries in Program Header Table
+	.hword 0x1       # TODO: Number Of Entries in Program Header Table
 	.hword 0x40      # Section Header Table Entry Size
 	.hword 0x3       # TODO: Number Of Entries in Section Header Table
 	.hword 0x2       # TODO: Index of Section Header Table Entry containing section names
 
-c_elf_data_program_header:
-	.int 0x1         # Loadable
-	.int 0x6         # Read Write
-	.quad 0x1b0      # Offset in ELF
-	.quad 0x3001b0   # Virtual Address
-	.quad 0x3001b0   # Physical Address
-	.quad 0x400      # Virtual Size
-	.quad 0x400      # Size in file
-	.quad 0x1000     # Aligning
-
-c_elf_data_section_header:
-	.int 0x1         # Index of name in SHSTRTAB
-	.int 0x1         # Load as Program data
-	.quad 0x3        # Is Writable and Readable
-	.quad 0x3001b0   # Virtual Address
-	.quad 0x1b0      # Offset in ELF
-	.quad 0x400      # Size
-	.int 0x0         # Index
-	.int 0x0         # Info
-	.quad 0x1000     # Aligning
-	.quad 0x0
+c_elf_null_section_header:
+	.fill 0x40, 1, 0
 
 c_elf_shstrtab_section_header:
-	.int 0xb         # Index of name in SHSTRTAB
+	.int 0x6         # Index of name in SHSTRTAB
 	.int 0x3         # Don't load
 	.quad 0x0        # No Attributes
 	.quad 0x0        # Not mapped to virtual memory
-	.quad 0x170      # Offset in ELF
-	.quad 0x40       # Size in ELF
+	.quad 0x138      # Offset in ELF
+	.quad 0xf        # Size in ELF
 	.int 0x0         # Index
-	.int 0x0         # No Inof
+	.int 0x0         # No Info
 	.quad 0x1        # Aligning
 	.quad 0x0
 
 
 c_elf_shstrtab:
 	.byte 0
-	.asciz "data"
 	.asciz "code"
 	.asciz "shstrtab"
-
-c_elf_data:
-	.fill 0x400, 1, 0
+	.byte 0
 
 c_usage_message:
 	.asciz "bfc [input file] [output file]\n"
@@ -139,9 +124,9 @@ c_usage_message:
 c_elf_code_program_header:
 	.int 0x1         # Loadable
 	.int 0x5         # Read Executable
-	.quad 0x5b0      # Offset in ELF
-	.quad 0x4005b0   # Virtual Address
-	.quad 0x4005b0   # Physical Address
+	.quad 0x148      # Offset in ELF
+	.quad 0x400148   # Virtual Address
+	.quad 0x400148   # Physical Address
 v_elf_code_program_header_file_size:
 	.quad 0x0        # File Size
 v_elf_code_program_header_memory_size:
@@ -149,11 +134,11 @@ v_elf_code_program_header_memory_size:
 	.quad 0x1000     # Aligning
 
 c_elf_code_section_header:
-	.int 0x6         # Index of name in SHSTRTAB
+	.int 0x1         # Index of name in SHSTRTAB
 	.int 0x1         # Load as program data
 	.quad 0x6        # Is Readable and Executable
-	.quad 0x4005b0   # Virtual Address
-	.quad 0x5b0      # Offset in ELF
+	.quad 0x400148   # Virtual Address
+	.quad 0x148      # Offset in ELF
 v_elf_code_section_header_size:
 	.quad 0x0
 	.int 0x0         # Index
@@ -298,15 +283,11 @@ l_read_loop_end:
 	mov $0x40, %rdx
 	call f_write_to_output
 
-	mov $c_elf_data_program_header, %rsi
-	mov $0x38, %rdx
-	call f_write_to_output
-
 	mov $c_elf_code_program_header, %rsi
 	mov $0x38, %rdx
 	call f_write_to_output
 
-	mov $c_elf_data_section_header, %rsi
+	mov $c_elf_null_section_header, %rsi
 	mov $0x40, %rdx
 	call f_write_to_output
 
@@ -319,11 +300,7 @@ l_read_loop_end:
 	call f_write_to_output
 
 	mov $c_elf_shstrtab, %rsi
-	mov $0x40, %rdx
-	call f_write_to_output
-
-	mov $c_elf_data, %rsi
-	mov $0x400, %rdx
+	mov $0x10, %rdx
 	call f_write_to_output
 
 	mov $v_buffer_start, %rbx