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Add support for OpenBSD 

It just rejects the generic System V ABI and has other syscall numbers.
This commit is contained in:
Přemysl Eric Janouch 2016-12-24 22:27:38 +01:00
parent cf6c1e67ba
commit b846a7a0ea
Signed by: p
GPG Key ID: B715679E3A361BE6
3 changed files with 21 additions and 8 deletions
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8
Makefile
View File

@ -1,11 +1,13 @@
# All we need is C99 and POSIX, which this should make available # All we need is C99 and POSIX, which this should make available
CFLAGS = -std=gnu99 CFLAGS = -std=gnu99
NAMES = bfc-amd64-linux NAMES = bfc-amd64-linux bfc-amd64-openbsd
all: $(NAMES) all: $(NAMES)
%: %.c %-linux: %.c
$(CC) $(CPPFLAGS) $(CFLAGS) $< -o $@ $(CC) $(CPPFLAGS) $(CFLAGS) $< -o $@ -DTARGET_LINUX
%-openbsd: %.c
$(CC) $(CPPFLAGS) $(CFLAGS) $< -o $@ -DTARGET_OPENBSD
clean: clean:
rm -f $(NAMES) rm -f $(NAMES)

6
README.adoc
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@ -1,8 +1,8 @@
bfc bfc
=== ===
'bfc' is a small, fast, self-contained, optimizing Brainfuck compiler for Linux 'bfc' is a small, fast, self-contained, optimizing Brainfuck compiler for *nix
on Intel x86-64. on Intel x86-64. Currently supported targets are Linux and OpenBSD.
Also included are several interpreters in various states of sophistication that Also included are several interpreters in various states of sophistication that
document my progress as I was writing this, from the simplest approach to an document my progress as I was writing this, from the simplest approach to an
@ -14,7 +14,7 @@ The compiler itself is platform agnostic.
Building Building
-------- --------
Build dependencies: a C99 compiler + Build dependencies: a C99 compiler +
Runtime dependencies: Linux Runtime dependencies: Linux or OpenBSD
$ git clone https://github.com/pjanouch/bfc.git $ git clone https://github.com/pjanouch/bfc.git
$ cd bfc $ cd bfc

15
bfc-amd64-linux.c → bfc-amd64.c
View File

@ -580,7 +580,13 @@ main (int argc, char *argv[])
// args -> rdi, rsi, rdx, r10, r8, r9 // args -> rdi, rsi, rdx, r10, r8, r9
// trashed <- rcx, r11 // trashed <- rcx, r11
#ifdef TARGET_OPENBSD
enum { SYS_READ = 3, SYS_WRITE = 4, SYS_EXIT = 1 };
#elif defined TARGET_LINUX
enum { SYS_READ = 0, SYS_WRITE = 1, SYS_EXIT = 60 }; enum { SYS_READ = 0, SYS_WRITE = 1, SYS_EXIT = 60 };
#else
#error Target not supported
#endif
CODE ("\xB8") DD (SYS_EXIT) // mov eax, 0x3c CODE ("\xB8") DD (SYS_EXIT) // mov eax, 0x3c
CODE ("\x48\x31\xFF") // xor rdi, rdi CODE ("\x48\x31\xFF") // xor rdi, rdi
@ -605,7 +611,7 @@ main (int argc, char *argv[])
size_t read_offset = buffer.len; size_t read_offset = buffer.len;
CODE ("\x50") // push rax -- save tape position CODE ("\x50") // push rax -- save tape position
CODE ("\xB8") DD (SYS_READ) // mov eax, "SYS_READ" CODE ("\xB8") DD (SYS_READ) // mov eax, "SYS_READ"
CODE ("\x48\x89\xC7") // mov rdi, rax -- STDIN_FILENO CODE ("\xBF") DD (0) // mov edi, "STDIN_FILENO"
CODE ("\x66\x6A\x00") // push word 0 -- the default value for EOF CODE ("\x66\x6A\x00") // push word 0 -- the default value for EOF
CODE ("\x48\x89\xE6") // mov rsi, rsp -- the char starts at rsp CODE ("\x48\x89\xE6") // mov rsi, rsp -- the char starts at rsp
CODE ("\xBA") DD (1) // mov edx, 1 -- count CODE ("\xBA") DD (1) // mov edx, 1 -- count
@ -623,7 +629,7 @@ main (int argc, char *argv[])
size_t write_offset = buffer.len; size_t write_offset = buffer.len;
CODE ("\x50") // push rax -- save tape position CODE ("\x50") // push rax -- save tape position
CODE ("\xB8") DD (SYS_WRITE) // mov eax, "SYS_WRITE" CODE ("\xB8") DD (SYS_WRITE) // mov eax, "SYS_WRITE"
CODE ("\x48\x89\xC7") // mov rdi, rax -- STDOUT_FILENO CODE ("\xBF") DD (1) // mov edi, "STDOUT_FILENO"
CODE ("\x66\x53") // push bx CODE ("\x66\x53") // push bx
CODE ("\x48\x89\xE6") // mov rsi, rsp -- the char starts at rsp CODE ("\x48\x89\xE6") // mov rsi, rsp -- the char starts at rsp
CODE ("\xBA") DD (1) // mov edx, 1 -- count CODE ("\xBA") DD (1) // mov edx, 1 -- count
@ -683,7 +689,12 @@ main (int argc, char *argv[])
// ELF header // ELF header
CODE ("\x7F" "ELF\x02\x01\x01") // ELF, 64-bit, little endian, v1 CODE ("\x7F" "ELF\x02\x01\x01") // ELF, 64-bit, little endian, v1
#ifdef TARGET_OPENBSD
// OpenBSD either requires its ABI or a PT_NOTE with "OpenBSD" in it
CODE ("\x0C\x00" "\0\0\0\0\0\0\0") // OpenBSD ABI, v0, padding
#else
CODE ("\x00\x00" "\0\0\0\0\0\0\0") // Unix System V ABI, v0, padding CODE ("\x00\x00" "\0\0\0\0\0\0\0") // Unix System V ABI, v0, padding
#endif
DW (2) DW (62) DD (1) // executable, x86-64, v1 DW (2) DW (62) DD (1) // executable, x86-64, v1
DQ (ELF_LOAD_CODE + ELF_META_SIZE) // entry point address DQ (ELF_LOAD_CODE + ELF_META_SIZE) // entry point address
DQ (ELF_HEADER_SIZE) DQ (0) // program, section header offset DQ (ELF_HEADER_SIZE) DQ (0) // program, section header offset