hex0 stage

stages/hex0/Makefile

@@ -0,0 +1,15 @@
+BUILD = ../build
+
+all: $(BUILD)/stage0
+
+stage0: $(BUILD)/stage0
+
+stage0-bootstrap: $(BUILD)/stage0-bootstrap
+
+$(BUILD)/stage0-bootstrap: hex0.in
+	for x in `sed '/^#/d;s/#.*//;s/ *//' hex0.in`; do printf \\x$$x; done > $@
+	chmod +x $@
+
+$(BUILD)/stage0: $(BUILD)/stage0-bootstrap
+	$< < hex0.in > $@
+	chmod +x $@

stages/hex0/hex0.in

@@ -0,0 +1,205 @@
+# ELF header
+# e_ident: u128
+# Magic number: 0x7f454c46 = "\x7fELF"
+7f 45 4c 46
+02 # EI_CLASS: u8 = ELFCLASS64
+01 # EI_DATA: u8 = ELFDATA2LSB
+01 # EI_VERSION: u8 = EV_CURRENT
+00 # EI_OSABI: u8 = ELFOSABI_NONE
+00 # EI_ABIVERSION: u8 = 0
+00 00 00 00 00 00 00 # EI_PAD: [u8; 7]
+# e_type: u16 = E_EXEC
+02 00
+# e_machine: u16 = EM_X86_64
+3e 00
+# e_version: u32 = EV_CURRENT
+01 00 00 00
+# e_entry: u64 = 0x400000
+00 00 40 00 00 00 00 00
+# e_phoff: u64 = 0x40
+40 00 00 00 00 00 00 00
+# e_shoff: u64 = 0x0
+00 00 00 00 00 00 00 00
+# e_flags: u32 = 0
+00 00 00 00
+# e_ehsize: u16 = 64
+40 00
+# e_phentsize: u16 = 56
+38 00
+# e_phnum: u16 = 1
+01 00
+# e_shentsize: u16 = 0
+00 00
+# e_shnum: u16 = 0
+00 00
+# e_shstrndx: u16 = 0
+00 00
+# End of ELF header
+#
+# Program header
+# p_type: u32 = PT_LOAD
+01 00 00 00
+# p_flags: u32 = PF_R | PF_X
+05 00 00 00
+# p_offset: u64 = 0
+00 00 00 00 00 00 00 00
+# p_vaddr: u64 = 0x400000
+00 00 40 00 00 00 00 00
+# p_paddr: u64 = 0x0
+00 00 00 00 00 00 00 00
+# p_filesz: u64 = 0x164
+64 01 00 00 00 00 00 00
+# p_memsz: u64 = 0x1000
+00 10 00 00 00 00 00 00
+# p_align: u64 = 0x1000
+00 10 00 00 00 00 00 00
+# End of program header
+#
+# Code segment (offset 0x40, virtual address 0x400000)
+#
+# _start:
+# ; alloca 0x1000 bytes on the stack
+# mov rbp, rsp
+48 89 e5
+# sub rsp, 0x1000
+48 81 ec 00 10 00 00
+# ; read 0x800 bytes from stdin into the stack
+# .READ: (_start+10)
+# xor rax, rax
+48 31 c0
+# mov edi, 0 (stdin)
+48 c7 c7 00 00 00 00
+# mov rsi, rsp
+48 89 e6
+# mov rdx, 0x800
+48 c7 c2 00 08 00 00
+# syscall (sys_read)
+0f 05
+# cmp rax, 0
+48 83 f8 00
+# jle die
+0f 8e a1 00 00 00 # 203 - 42 = 161 = 0xa1
+## (_start+42)
+# ; end = r8
+# mov r8, rax
+49 89 c0
+# add r8, rsp
+49 01 e0
+# ; pos = r9
+# mov r9, rsp
+49 89 e1
+# ; dst = r10
+# mov r10, rsp
+49 89 e2
+# add r10, 0x800
+49 81 c2 00 08 00 00
+# ; while (pos < end) {
+# ; .L0: (_start+61)
+# cmp r9, r8
+4d 39 c1
+# jge .L3
+0f 8d 60 00 00 00 ; 166 - 70 = 96 = 0x60
+# (_start+70)
+#
+# ; if (*pos == '#') {
+# mov al , byte [r9]
+41 8a 41 00
+# cmp al, '#'
+3c 23
+# jne .L1 ; 100 - 82 = 18 = 0x12
+0f 85 12 00 00 00
+# (_start+82)
+# ; while (*pos != '\n') pos++;
+# ; .L2: (_start+82)
+# inc r9
+49 ff c1
+# cmp byte [r9], '\n'
+41 80 39 0a
+# jne .L2 ; 82 - 95 = -13 = 0xfffffffffffffff3 = 0xf3
+0f 85 f3 ff ff ff
+# (_start+95)
+# jmp .L0 ; 61 - 100 = -39 = 0xfffffffffffffd89 = 0xfd89
+e9 89 fd ff ff
+# (_start+100)
+# ; .L1: (_start+100)
+# ; convert *pos to high word
+# mov bl, al
+88 c3
+# sub bl, 'a'
+80 eb 61
+# add bl, 10
+80 c3 0a
+# sub al, '0'
+2c 30
+# cmp al, 10
+3c 0a
+# cmovge eax, ebx
+0f 43 c3
+# shl al, 4
+c0 e0 04
+# ; pos++
+# inc r9
+49 ff c1
+# ; convert *pos to low word
+# mov bl, byte [r9]
+41 8a 19
+# mov cl, bl
+88 d9
+# sub cl, 'a'
+80 e9 61
+# add cl, 10
+80 c1 0a
+# sub bl, '0'
+80 eb 30
+# cmp bl, 10
+80 fb 0a
+# cmovge ebx, ecx
+0f 4d d9
+# ; combine high and low word
+# or al, bl
+08 d8
+# ; write the byte to dst
+# mov byte [r10], al
+41 88 02
+# inc r10
+41 ff c2
+# ; if (*pos != '\n') pos++;
+# cmp byte [r9], '\n'
+41 80 39 0a
+# inc r9
+49 ff c1
+# je .L0 ; 61 - 161 = -100 = 0xffffffffffffff9c = 0x9c
+0f 84 9c ff ff ff
+## (_start+161)
+# jmp .L1 ; 100 - 166 = -66 = 0xffffffffffffffbe = 0xbe
+e9 be ff ff ff
+## (_start+166)
+# ; }
+# .L3: (_start+166)
+# ; write the decoded bytes to stdout
+# mov rax, 1 (sys_write)
+48 c7 c0 01 00 00 00
+# mov rdi, 1 (stdout)
+48 c7 c7 01 00 00 00
+# mov rsi, rsp
+48 89 e6
+# add rsi, 0x800
+48 81 c6 00 08 00 00
+# mov rdx, r10
+4c 89 d2
+# sub rdx, rsi
+48 29 f2
+# syscall
+0f 05
+# jmp .READ ; 10 - 203 = -193 = 0xffffffffffffff3f = 0x3f
+e9 3f ff ff ff
+## (_start+203)
+#
+# die: (_start+203)
+# mov rax, 60 (sys_exit)
+48 c7 c0 3c 00 00 00
+# xor rdi, rdi
+48 31 ff
+# syscall
+0f 05
+# _start+215