Initial import

Author: jart

.clang-format

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+---
+BasedOnStyle: Google
+StatementMacros:
+  - INITIALIZER
+AlignConsecutiveMacros: true
+AlignConsecutiveDeclarations: false
+AlwaysBreakBeforeMultilineStrings: false
+AllowShortFunctionsOnASingleLine: false
+KeepEmptyLinesAtTheStartOfBlocks: true
+ConstructorInitializerAllOnOneLineOrOnePerLine: true
+---
+Language: Cpp
+AllowShortFunctionsOnASingleLine: false
+---
+Language: Proto
+...

.gitattributes

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+# -*- conf -*-
+*.xz binary
+*.com binary
+*.elf binary

.gitignore

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+# -*- conf -*-
+*.xz
+/o
+/HTAGS
+/TAGS
+/perf.data
+/perf.data.old

LICENSE

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+ISC License
+
+Copyright 2022 Justine Alexandra Roberts Tunney
+
+Permission to use, copy, modify, and/or distribute this software for
+any purpose with or without fee is hereby granted, provided that the
+above copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
+WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
+AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
+DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
+PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+PERFORMANCE OF THIS SOFTWARE.

Makefile

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+#-*-mode:makefile-gmake;indent-tabs-mode:t;tab-width:8;coding:utf-8-*-┐
+#───vi: set et ft=make ts=8 tw=8 fenc=utf-8 :vi───────────────────────┘
+
+SHELL = /bin/sh
+MAKEFLAGS += --no-builtin-rules
+
+.SUFFIXES:
+.DELETE_ON_ERROR:
+.FEATURES: output-sync
+.PHONY: o clean
+
+o: o/$(MODE)/blink
+test: o/$(MODE)/test
+clean:; rm -rf o
+tags: TAGS HTAGS
+
+include build/config.mk
+include build/rules.mk
+include blink/blink.mk
+include test/test.mk
+include test/blink/test.mk
+include third_party/gcc/gcc.mk
+include third_party/qemu/qemu.mk
+
+OBJS	 = $(foreach x,$(PKGS),$($(x)_OBJS))
+SRCS	:= $(foreach x,$(PKGS),$($(x)_SRCS))
+HDRS	:= $(foreach x,$(PKGS),$($(x)_HDRS))
+INCS	 = $(foreach x,$(PKGS),$($(x)_INCS))
+BINS	 = $(foreach x,$(PKGS),$($(x)_BINS))
+TESTS	 = $(foreach x,$(PKGS),$($(x)_TESTS))
+CHECKS	 = $(foreach x,$(PKGS),$($(x)_CHECKS))
+
+o/$(MODE)/.x:
+	mkdir -p $(@D)
+	touch $@
+o/$(MODE)/srcs.txt: o/$(MODE)/.x $(MAKEFILES) $(call uniq,$(foreach x,$(SRCS),$(dir $(x))))
+	$(file >$@) $(foreach x,$(SRCS),$(file >>$@,$(x)))
+o/$(MODE)/hdrs.txt: o/$(MODE)/.x $(MAKEFILES) $(call uniq,$(foreach x,$(HDRS) $(INCS),$(dir $(x))))
+	$(file >$@) $(foreach x,$(HDRS) $(INCS),$(file >>$@,$(x)))
+
+DEPENDS =				\
+	o/$(MODE)/depend.host		\
+	o/$(MODE)/depend.i486		\
+	o/$(MODE)/depend.m68k		\
+	o/$(MODE)/depend.x86_64		\
+	o/$(MODE)/depend.arm		\
+	o/$(MODE)/depend.aarch64	\
+	o/$(MODE)/depend.riscv64	\
+	o/$(MODE)/depend.mips		\
+	o/$(MODE)/depend.mipsel		\
+	o/$(MODE)/depend.mips64		\
+	o/$(MODE)/depend.mips64el	\
+	o/$(MODE)/depend.s390x		\
+	o/$(MODE)/depend.microblaze	\
+	o/$(MODE)/depend.powerpc	\
+	o/$(MODE)/depend.powerpc64le
+
+o/$(MODE)/depend: $(DEPENDS)
+	cat $^ >$@
+o/$(MODE)/depend.host: build/bootstrap/mkdeps.com o/$(MODE)/srcs.txt o/$(MODE)/hdrs.txt
+	build/bootstrap/mkdeps.com -o $@ -r o/$(MODE)/ @o/$(MODE)/srcs.txt @o/$(MODE)/hdrs.txt
+o/$(MODE)/depend.i486: build/bootstrap/mkdeps.com o/$(MODE)/srcs.txt o/$(MODE)/hdrs.txt
+	build/bootstrap/mkdeps.com -o $@ -r o/$(MODE)/i486/ @o/$(MODE)/srcs.txt @o/$(MODE)/hdrs.txt
+o/$(MODE)/depend.m68k: build/bootstrap/mkdeps.com o/$(MODE)/srcs.txt o/$(MODE)/hdrs.txt
+	build/bootstrap/mkdeps.com -o $@ -r o/$(MODE)/m68k/ @o/$(MODE)/srcs.txt @o/$(MODE)/hdrs.txt
+o/$(MODE)/depend.x86_64: build/bootstrap/mkdeps.com o/$(MODE)/srcs.txt o/$(MODE)/hdrs.txt
+	build/bootstrap/mkdeps.com -o $@ -r o/$(MODE)/x86_64/ @o/$(MODE)/srcs.txt @o/$(MODE)/hdrs.txt
+o/$(MODE)/depend.x86_64-gcc48: build/bootstrap/mkdeps.com o/$(MODE)/srcs.txt o/$(MODE)/hdrs.txt
+	build/bootstrap/mkdeps.com -o $@ -r o/$(MODE)/x86_64-gcc48/ @o/$(MODE)/srcs.txt @o/$(MODE)/hdrs.txt
+o/$(MODE)/depend.arm: build/bootstrap/mkdeps.com o/$(MODE)/srcs.txt o/$(MODE)/hdrs.txt
+	build/bootstrap/mkdeps.com -o $@ -r o/$(MODE)/arm/ @o/$(MODE)/srcs.txt @o/$(MODE)/hdrs.txt
+o/$(MODE)/depend.aarch64: build/bootstrap/mkdeps.com o/$(MODE)/srcs.txt o/$(MODE)/hdrs.txt
+	build/bootstrap/mkdeps.com -o $@ -r o/$(MODE)/aarch64/ @o/$(MODE)/srcs.txt @o/$(MODE)/hdrs.txt
+o/$(MODE)/depend.riscv64: build/bootstrap/mkdeps.com o/$(MODE)/srcs.txt o/$(MODE)/hdrs.txt
+	build/bootstrap/mkdeps.com -o $@ -r o/$(MODE)/riscv64/ @o/$(MODE)/srcs.txt @o/$(MODE)/hdrs.txt
+o/$(MODE)/depend.mips: build/bootstrap/mkdeps.com o/$(MODE)/srcs.txt o/$(MODE)/hdrs.txt
+	build/bootstrap/mkdeps.com -o $@ -r o/$(MODE)/mips/ @o/$(MODE)/srcs.txt @o/$(MODE)/hdrs.txt
+o/$(MODE)/depend.mipsel: build/bootstrap/mkdeps.com o/$(MODE)/srcs.txt o/$(MODE)/hdrs.txt
+	build/bootstrap/mkdeps.com -o $@ -r o/$(MODE)/mipsel/ @o/$(MODE)/srcs.txt @o/$(MODE)/hdrs.txt
+o/$(MODE)/depend.mips64: build/bootstrap/mkdeps.com o/$(MODE)/srcs.txt o/$(MODE)/hdrs.txt
+	build/bootstrap/mkdeps.com -o $@ -r o/$(MODE)/mips64/ @o/$(MODE)/srcs.txt @o/$(MODE)/hdrs.txt
+o/$(MODE)/depend.mips64el: build/bootstrap/mkdeps.com o/$(MODE)/srcs.txt o/$(MODE)/hdrs.txt
+	build/bootstrap/mkdeps.com -o $@ -r o/$(MODE)/mips64el/ @o/$(MODE)/srcs.txt @o/$(MODE)/hdrs.txt
+o/$(MODE)/depend.s390x: build/bootstrap/mkdeps.com o/$(MODE)/srcs.txt o/$(MODE)/hdrs.txt
+	build/bootstrap/mkdeps.com -o $@ -r o/$(MODE)/s390x/ @o/$(MODE)/srcs.txt @o/$(MODE)/hdrs.txt
+o/$(MODE)/depend.microblaze: build/bootstrap/mkdeps.com o/$(MODE)/srcs.txt o/$(MODE)/hdrs.txt
+	build/bootstrap/mkdeps.com -o $@ -r o/$(MODE)/microblaze/ @o/$(MODE)/srcs.txt @o/$(MODE)/hdrs.txt
+o/$(MODE)/depend.powerpc: build/bootstrap/mkdeps.com o/$(MODE)/srcs.txt o/$(MODE)/hdrs.txt
+	build/bootstrap/mkdeps.com -o $@ -r o/$(MODE)/powerpc/ @o/$(MODE)/srcs.txt @o/$(MODE)/hdrs.txt
+o/$(MODE)/depend.powerpc64le: build/bootstrap/mkdeps.com o/$(MODE)/srcs.txt o/$(MODE)/hdrs.txt
+	build/bootstrap/mkdeps.com -o $@ -r o/$(MODE)/powerpc64le/ @o/$(MODE)/srcs.txt @o/$(MODE)/hdrs.txt
+
+TAGS:	o/$(MODE)/srcs.txt $(SRCS)
+	$(RM) $@
+	$(TAGS) $(TAGSFLAGS) -L $< -o $@
+
+HTAGS:	o/$(MODE)/hdrs.txt $(HDRS)
+	$(RM) $@
+	build/htags -L $< -o $@
+
+$(SRCS):
+$(HDRS):
+$(INCS):
+.DEFAULT:
+	@echo >&2
+	@echo NOTE: deleting o/$(MODE)/depend because of an unspecified prerequisite: $@ >&2
+	@echo >&2
+	rm -f o/$(MODE)/depend $(DEPENDS)
+
+-include o/$(MODE)/depend

README.md

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+# blink
+
+blink is an emulator for running x86-64-linux programs on different
+operating systems and hardware architectures. It's designed to do the
+same thing as the `qemu-x86_64` command, except rather than being a 10mb
+binary, blink only has a ~200kb footprint. For further details on the
+motivations for this tool, please read <https://justine.lol/ape.html>.
+
+## Getting Started
+
+You can compile blink on x86-64 Linux, Darwin, FreeBSD, NetBSD, OpenBSD,
+or Apple Silicon with Rosetta installed, using your platform toolchain.
+
+```sh
+$ make -j8 o///blink/blink
+$ o///blink/blink third_party/cosmo/hello.com
+hello world
+$ o///blink/blink third_party/cosmo/tinyhello.elf
+hello world
+```
+
+There's a terminal interface for debugging:
+
+```
+$ make -j8 o///blink/tui
+$ o///blink/tui third_party/cosmo/tinyhello.elf
+```
+
+On x86-64 Linux you can cross-compile blink for Linux systems with x86,
+arm, m68k, riscv, mips, s390x, powerpc, or microblaze cpus. This happens
+using vendored musl-cross-make toolchains and static qemu for testing.
+
+```sh
+$ make -j8 test
+$ o/third_party/qemu/qemu-aarch64 o//aarch64/blink/blink third_party/cosmo/hello.com
+hello world
+```
+
+## Technical Details
+
+blink is an x86-64 interpreter written in straightforward POSIX ANSI C.
+Similar to Bochs, there's no JIT or code generation currently in blink.
+Therefore you're trading away performance for a tinier emulator that'll
+just work, is ISC (rather than GPL) licensed and it won't let untrusted
+code get too close to your hardware. Instruction decoding is done using
+our trimmed-down version of Intel's disassembler Xed.

blink/address.c

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+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2022 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ Permission to use, copy, modify, and/or distribute this software for         │
+│ any purpose with or without fee is hereby granted, provided that the         │
+│ above copyright notice and this permission notice appear in all copies.      │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
+│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
+│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
+│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
+│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
+│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
+│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
+│ PERFORMANCE OF THIS SOFTWARE.                                                │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "blink/address.h"
+#include "blink/builtin.h"
+#include "blink/endian.h"
+#include "blink/modrm.h"
+#include "blink/throw.h"
+#include "blink/x86.h"
+
+uint64_t AddressOb(struct Machine *m, uint32_t rde) {
+  return AddSegment(m, rde, m->xedd->op.disp, m->ds);
+}
+
+uint8_t *GetSegment(struct Machine *m, uint32_t rde, int s) {
+  switch (s & 7) {
+    case 0:
+      return m->es;
+    case 1:
+      return m->cs;
+    case 2:
+      return m->ss;
+    case 3:
+      return m->ds;
+    case 4:
+      return m->fs;
+    case 5:
+      return m->gs;
+    case 6:
+    case 7:
+      OpUd(m, rde);
+    default:
+      __builtin_unreachable();
+  }
+}
+
+uint64_t DataSegment(struct Machine *m, uint32_t rde, uint64_t i) {
+  return AddSegment(m, rde, i, m->ds);
+}
+
+uint64_t AddressSi(struct Machine *m, uint32_t rde) {
+  switch (Eamode(rde)) {
+    case XED_MODE_LONG:
+      return DataSegment(m, rde, Read64(m->si));
+    case XED_MODE_REAL:
+      return DataSegment(m, rde, Read16(m->si));
+    case XED_MODE_LEGACY:
+      return DataSegment(m, rde, Read32(m->si));
+    default:
+      __builtin_unreachable();
+  }
+}
+
+uint64_t AddressDi(struct Machine *m, uint32_t rde) {
+  uint64_t i = Read64(m->es);
+  switch (Eamode(rde)) {
+    case XED_MODE_LONG:
+      return i + Read64(m->di);
+    case XED_MODE_REAL:
+      return i + Read16(m->di);
+    case XED_MODE_LEGACY:
+      return i + Read32(m->di);
+    default:
+      __builtin_unreachable();
+  }
+}

blink/address.h

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+#ifndef BLINK_ADDRESS_H_
+#define BLINK_ADDRESS_H_
+#include "blink/endian.h"
+#include "blink/machine.h"
+#include "blink/modrm.h"
+
+uint64_t AddressOb(struct Machine *, uint32_t);
+uint64_t AddressDi(struct Machine *, uint32_t);
+uint64_t AddressSi(struct Machine *, uint32_t);
+uint8_t *GetSegment(struct Machine *, uint32_t, int);
+uint64_t DataSegment(struct Machine *, uint32_t, uint64_t);
+
+static inline uint64_t MaskAddress(uint32_t mode, uint64_t x) {
+  if (mode != XED_MODE_LONG) {
+    if (mode == XED_MODE_REAL) {
+      x &= 0xffff;
+    } else {
+      x &= 0xffffffff;
+    }
+  }
+  return x;
+}
+
+static inline uint64_t AddSegment(struct Machine *m, uint32_t rde, uint64_t i,
+                                  const uint8_t s[8]) {
+  if (!Sego(rde)) {
+    return i + Read64(s);
+  } else {
+    return i + Read64(GetSegment(m, rde, Sego(rde) - 1));
+  }
+}
+
+#endif /* BLINK_ADDRESS_H_ */