From 8aad5f45d57ca5e2e51176c9d6aa22583b6cf91d Mon Sep 17 00:00:00 2001
From: Mike Leany <55358344+mikeleany@users.noreply.github.com>
Date: Fri, 17 Sep 2021 23:03:59 -0600
Subject: [PATCH 01/15] Add new target: `x86_64-unknown-none-elf`

---
 compiler/rustc_target/src/spec/mod.rs         |  2 ++
 .../src/spec/x86_64_unknown_none_elf.rs       | 29 +++++++++++++++++++
 2 files changed, 31 insertions(+)
 create mode 100644 compiler/rustc_target/src/spec/x86_64_unknown_none_elf.rs

diff --git a/compiler/rustc_target/src/spec/mod.rs b/compiler/rustc_target/src/spec/mod.rs
index ff5dfa3f74625..4b357b3cca1ba 100644
--- a/compiler/rustc_target/src/spec/mod.rs
+++ b/compiler/rustc_target/src/spec/mod.rs
@@ -954,6 +954,8 @@ supported_targets! {
     ("armv6k-nintendo-3ds", armv6k_nintendo_3ds),
 
     ("armv7-unknown-linux-uclibceabihf", armv7_unknown_linux_uclibceabihf),
+
+    ("x86_64-unknown-none-elf", x86_64_unknown_none_elf),
 }
 
 /// Warnings encountered when parsing the target `json`.
diff --git a/compiler/rustc_target/src/spec/x86_64_unknown_none_elf.rs b/compiler/rustc_target/src/spec/x86_64_unknown_none_elf.rs
new file mode 100644
index 0000000000000..2086a1a8d5b3d
--- /dev/null
+++ b/compiler/rustc_target/src/spec/x86_64_unknown_none_elf.rs
@@ -0,0 +1,29 @@
+// Generic AArch64 target for bare-metal code - Floating point disabled
+//
+// Can be used in conjunction with the `target-feature` and
+// `target-cpu` compiler flags to opt-in more hardware-specific
+// features.
+//
+// For example, `-C target-cpu=cortex-a53`.
+
+use super::{LinkerFlavor, LldFlavor, PanicStrategy, Target, TargetOptions};
+
+pub fn target() -> Target {
+    let opts = TargetOptions {
+        abi: "softfloat".to_string(),
+        linker_flavor: LinkerFlavor::Lld(LldFlavor::Ld),
+        linker: Some("rust-lld".to_owned()),
+        features: "-mmx,-sse,+soft-float".to_string(),
+        executables: true,
+        disable_redzone: true,
+        panic_strategy: PanicStrategy::Abort,
+        ..Default::default()
+    };
+    Target {
+        llvm_target: "x86_64-unknown-none-elf".to_string(),
+        pointer_width: 64,
+        data_layout: "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128".to_string(),
+        arch: "x86_64".to_string(),
+        options: opts,
+    }
+}

From 80654c3d93e7bb7d8b53a88be45c3e31ea480cdd Mon Sep 17 00:00:00 2001
From: Mike Leany <55358344+mikeleany@users.noreply.github.com>
Date: Sat, 18 Sep 2021 08:21:52 -0600
Subject: [PATCH 02/15] Fix code formatting.

---
 compiler/rustc_target/src/spec/x86_64_unknown_none_elf.rs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/compiler/rustc_target/src/spec/x86_64_unknown_none_elf.rs b/compiler/rustc_target/src/spec/x86_64_unknown_none_elf.rs
index 2086a1a8d5b3d..8cae3d0174d62 100644
--- a/compiler/rustc_target/src/spec/x86_64_unknown_none_elf.rs
+++ b/compiler/rustc_target/src/spec/x86_64_unknown_none_elf.rs
@@ -22,7 +22,8 @@ pub fn target() -> Target {
     Target {
         llvm_target: "x86_64-unknown-none-elf".to_string(),
         pointer_width: 64,
-        data_layout: "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128".to_string(),
+        data_layout: "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+            .to_string(),
         arch: "x86_64".to_string(),
         options: opts,
     }

From dcbdb6e4f5a06737418d44b3432dae5c592b6a75 Mon Sep 17 00:00:00 2001
From: Mike Leany <55358344+mikeleany@users.noreply.github.com>
Date: Sat, 18 Sep 2021 09:46:25 -0600
Subject: [PATCH 03/15] Add `x86_64-unknown-none-elf` to `platform-support.md`.

---
 src/doc/rustc/src/platform-support.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/doc/rustc/src/platform-support.md b/src/doc/rustc/src/platform-support.md
index bbeab598f2292..62084d2a9dbd1 100644
--- a/src/doc/rustc/src/platform-support.md
+++ b/src/doc/rustc/src/platform-support.md
@@ -285,6 +285,7 @@ target | std | host | notes
 `x86_64-unknown-haiku` | ✓ | ✓ | 64-bit Haiku
 `x86_64-unknown-hermit` | ? |  |
 `x86_64-unknown-l4re-uclibc` | ? |  |
+`x86_64-unknown-none-elf` | * |  | Bare x86_64, softfloat
 `x86_64-unknown-none-hermitkernel` | ? |  | HermitCore kernel
 `x86_64-unknown-none-linuxkernel` | * |  | Linux kernel modules
 `x86_64-unknown-openbsd` | ✓ | ✓ | 64-bit OpenBSD

From 5ba3a651f982fd716f5993b56961d2c3a535b7d8 Mon Sep 17 00:00:00 2001
From: Mike Leany <55358344+mikeleany@users.noreply.github.com>
Date: Sun, 19 Sep 2021 07:57:49 -0600
Subject: [PATCH 04/15] Use `CodeModel::Kernel` for `x86_64-unknown-none-elf`.

---
 compiler/rustc_target/src/spec/x86_64_unknown_none_elf.rs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/compiler/rustc_target/src/spec/x86_64_unknown_none_elf.rs b/compiler/rustc_target/src/spec/x86_64_unknown_none_elf.rs
index 8cae3d0174d62..58a83e75e4130 100644
--- a/compiler/rustc_target/src/spec/x86_64_unknown_none_elf.rs
+++ b/compiler/rustc_target/src/spec/x86_64_unknown_none_elf.rs
@@ -6,7 +6,7 @@
 //
 // For example, `-C target-cpu=cortex-a53`.
 
-use super::{LinkerFlavor, LldFlavor, PanicStrategy, Target, TargetOptions};
+use super::{CodeModel, LinkerFlavor, LldFlavor, PanicStrategy, Target, TargetOptions};
 
 pub fn target() -> Target {
     let opts = TargetOptions {
@@ -17,6 +17,7 @@ pub fn target() -> Target {
         executables: true,
         disable_redzone: true,
         panic_strategy: PanicStrategy::Abort,
+        code_model: Some(CodeModel::Kernel),
         ..Default::default()
     };
     Target {

From a23ee64c2c292f30fa64b258042e256bca0f35a9 Mon Sep 17 00:00:00 2001
From: Josh Triplett <josh@joshtriplett.org>
Date: Sun, 19 Sep 2021 12:05:58 -0700
Subject: [PATCH 05/15] Rename x86_64-unknown-none-elf to x86_64-unknown-none

Most Rust freestanding/bare-metal targets use just `-unknown-none` here,
including aarch64-unknown-none, mipsel-unknown-none, and the BPF
targets. The *only* target using `-unknown-none-elf` is RISC-V.

The underlying toolchain doesn't care; LLVM accepts both `x86_64-unknown-none`
and `x86_64-unknown-none-elf`.

In addition, there's a long history of embedded x86 targets with varying
definitions for the `elf` suffix; on some of those embedded targets,
`elf` implied the inclusion of a C library based on newlib or similar.
Using `x86_64-unknown-none` avoids any potential ambiguity there.

(Work on this target sponsored by Profian.)
---
 compiler/rustc_target/src/spec/mod.rs                           | 2 +-
 .../spec/{x86_64_unknown_none_elf.rs => x86_64_unknown_none.rs} | 0
 src/doc/rustc/src/platform-support.md                           | 2 +-
 3 files changed, 2 insertions(+), 2 deletions(-)
 rename compiler/rustc_target/src/spec/{x86_64_unknown_none_elf.rs => x86_64_unknown_none.rs} (100%)

diff --git a/compiler/rustc_target/src/spec/mod.rs b/compiler/rustc_target/src/spec/mod.rs
index 4b357b3cca1ba..5bc6d1918dd7e 100644
--- a/compiler/rustc_target/src/spec/mod.rs
+++ b/compiler/rustc_target/src/spec/mod.rs
@@ -955,7 +955,7 @@ supported_targets! {
 
     ("armv7-unknown-linux-uclibceabihf", armv7_unknown_linux_uclibceabihf),
 
-    ("x86_64-unknown-none-elf", x86_64_unknown_none_elf),
+    ("x86_64-unknown-none", x86_64_unknown_none),
 }
 
 /// Warnings encountered when parsing the target `json`.
diff --git a/compiler/rustc_target/src/spec/x86_64_unknown_none_elf.rs b/compiler/rustc_target/src/spec/x86_64_unknown_none.rs
similarity index 100%
rename from compiler/rustc_target/src/spec/x86_64_unknown_none_elf.rs
rename to compiler/rustc_target/src/spec/x86_64_unknown_none.rs
diff --git a/src/doc/rustc/src/platform-support.md b/src/doc/rustc/src/platform-support.md
index 62084d2a9dbd1..0f2072bd52150 100644
--- a/src/doc/rustc/src/platform-support.md
+++ b/src/doc/rustc/src/platform-support.md
@@ -285,7 +285,7 @@ target | std | host | notes
 `x86_64-unknown-haiku` | ✓ | ✓ | 64-bit Haiku
 `x86_64-unknown-hermit` | ? |  |
 `x86_64-unknown-l4re-uclibc` | ? |  |
-`x86_64-unknown-none-elf` | * |  | Bare x86_64, softfloat
+`x86_64-unknown-none` | * |  | Freestanding/bare-metal x86_64, softfloat
 `x86_64-unknown-none-hermitkernel` | ? |  | HermitCore kernel
 `x86_64-unknown-none-linuxkernel` | * |  | Linux kernel modules
 `x86_64-unknown-openbsd` | ✓ | ✓ | 64-bit OpenBSD

From b0efa05e5acaaa6b973e05835d2fd46f58cc5c11 Mon Sep 17 00:00:00 2001
From: Josh Triplett <josh@joshtriplett.org>
Date: Sun, 19 Sep 2021 12:14:33 -0700
Subject: [PATCH 06/15] x86_64-unknown-none: Fix module comment

(Work on this target sponsored by Profian.)
---
 compiler/rustc_target/src/spec/x86_64_unknown_none.rs | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/compiler/rustc_target/src/spec/x86_64_unknown_none.rs b/compiler/rustc_target/src/spec/x86_64_unknown_none.rs
index 58a83e75e4130..a3ab2621c78b2 100644
--- a/compiler/rustc_target/src/spec/x86_64_unknown_none.rs
+++ b/compiler/rustc_target/src/spec/x86_64_unknown_none.rs
@@ -1,10 +1,8 @@
-// Generic AArch64 target for bare-metal code - Floating point disabled
+// Generic x86-64 target for bare-metal code - Floating point disabled
 //
 // Can be used in conjunction with the `target-feature` and
 // `target-cpu` compiler flags to opt-in more hardware-specific
 // features.
-//
-// For example, `-C target-cpu=cortex-a53`.
 
 use super::{CodeModel, LinkerFlavor, LldFlavor, PanicStrategy, Target, TargetOptions};
 

From b0d1e3be23bdaa4e103154750ef9bce7d05cf978 Mon Sep 17 00:00:00 2001
From: Josh Triplett <josh@joshtriplett.org>
Date: Sun, 19 Sep 2021 12:15:03 -0700
Subject: [PATCH 07/15] x86_64-unknown-none: Drop the `abi` field

(Work on this target sponsored by Profian.)
---
 compiler/rustc_target/src/spec/x86_64_unknown_none.rs | 1 -
 1 file changed, 1 deletion(-)

diff --git a/compiler/rustc_target/src/spec/x86_64_unknown_none.rs b/compiler/rustc_target/src/spec/x86_64_unknown_none.rs
index a3ab2621c78b2..8679814b782d7 100644
--- a/compiler/rustc_target/src/spec/x86_64_unknown_none.rs
+++ b/compiler/rustc_target/src/spec/x86_64_unknown_none.rs
@@ -8,7 +8,6 @@ use super::{CodeModel, LinkerFlavor, LldFlavor, PanicStrategy, Target, TargetOpt
 
 pub fn target() -> Target {
     let opts = TargetOptions {
-        abi: "softfloat".to_string(),
         linker_flavor: LinkerFlavor::Lld(LldFlavor::Ld),
         linker: Some("rust-lld".to_owned()),
         features: "-mmx,-sse,+soft-float".to_string(),

From 6ab66192f925802a81822e55855546342cb69d1c Mon Sep 17 00:00:00 2001
From: Josh Triplett <josh@joshtriplett.org>
Date: Sun, 19 Sep 2021 12:31:36 -0700
Subject: [PATCH 08/15] x86_64-unknown-none: Disable more target features

Based on the list used for x86_64-unknown-none-linuxkernel.

(Work on this target sponsored by Profian.)
---
 compiler/rustc_target/src/spec/x86_64_unknown_none.rs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/compiler/rustc_target/src/spec/x86_64_unknown_none.rs b/compiler/rustc_target/src/spec/x86_64_unknown_none.rs
index 8679814b782d7..4fe1b6e11e8e1 100644
--- a/compiler/rustc_target/src/spec/x86_64_unknown_none.rs
+++ b/compiler/rustc_target/src/spec/x86_64_unknown_none.rs
@@ -10,7 +10,9 @@ pub fn target() -> Target {
     let opts = TargetOptions {
         linker_flavor: LinkerFlavor::Lld(LldFlavor::Ld),
         linker: Some("rust-lld".to_owned()),
-        features: "-mmx,-sse,+soft-float".to_string(),
+        features:
+            "-mmx,-sse,-sse2,-sse3,-ssse3,-sse4.1,-sse4.2,-3dnow,-3dnowa,-avx,-avx2,+soft-float"
+                .to_string(),
         executables: true,
         disable_redzone: true,
         panic_strategy: PanicStrategy::Abort,

From 2037cee7012480ea84851bd1e85fc9693b321651 Mon Sep 17 00:00:00 2001
From: Josh Triplett <josh@joshtriplett.org>
Date: Sun, 19 Sep 2021 12:33:21 -0700
Subject: [PATCH 09/15] x86_64-unknown-none: Expand TargetOptions to specify
 more details

Specify the `cpu` and the `max_atomic_width` (64).

Set `stack_probes` similarly to other targets to work around known
issues, and copy the corresponding comment from those targets.

Build position-independent code that doesn't require relocations.

(Work on this target sponsored by Profian.)
---
 compiler/rustc_target/src/spec/x86_64_unknown_none.rs | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/compiler/rustc_target/src/spec/x86_64_unknown_none.rs b/compiler/rustc_target/src/spec/x86_64_unknown_none.rs
index 4fe1b6e11e8e1..b460ea1c29b55 100644
--- a/compiler/rustc_target/src/spec/x86_64_unknown_none.rs
+++ b/compiler/rustc_target/src/spec/x86_64_unknown_none.rs
@@ -8,6 +8,14 @@ use super::{CodeModel, LinkerFlavor, LldFlavor, PanicStrategy, Target, TargetOpt
 
 pub fn target() -> Target {
     let opts = TargetOptions {
+        cpu: "x86-64".to_string(),
+        max_atomic_width: Some(64),
+        // don't use probe-stack=inline-asm until rust#83139 and rust#84667 are resolved
+        stack_probes: StackProbeType::Call,
+        position_independent_executables: true,
+        static_position_independent_executables: true,
+        relro_level: RelroLevel::Full,
+        relocation_model: RelocModel::Static,
         linker_flavor: LinkerFlavor::Lld(LldFlavor::Ld),
         linker: Some("rust-lld".to_owned()),
         features:

From 7bb2f7dba07ac066d4150ef83cbc6c6a6d5f145b Mon Sep 17 00:00:00 2001
From: Josh Triplett <josh@joshtriplett.org>
Date: Sun, 19 Sep 2021 12:43:13 -0700
Subject: [PATCH 10/15] x86_64-unknown-none: Add target documentation

In particular, document the default properties and assumptions of code
built for the target.

(Work on this target sponsored by Profian.)
---
 src/doc/rustc/src/platform-support.md         |  2 +-
 .../platform-support/x86_64-unknown-none.md   | 76 +++++++++++++++++++
 2 files changed, 77 insertions(+), 1 deletion(-)
 create mode 100644 src/doc/rustc/src/platform-support/x86_64-unknown-none.md

diff --git a/src/doc/rustc/src/platform-support.md b/src/doc/rustc/src/platform-support.md
index 0f2072bd52150..6b0c336b3c799 100644
--- a/src/doc/rustc/src/platform-support.md
+++ b/src/doc/rustc/src/platform-support.md
@@ -285,7 +285,7 @@ target | std | host | notes
 `x86_64-unknown-haiku` | ✓ | ✓ | 64-bit Haiku
 `x86_64-unknown-hermit` | ? |  |
 `x86_64-unknown-l4re-uclibc` | ? |  |
-`x86_64-unknown-none` | * |  | Freestanding/bare-metal x86_64, softfloat
+[`x86_64-unknown-none`](platform-support/x86_64-unknown-none.md) | * |  | Freestanding/bare-metal x86_64, softfloat
 `x86_64-unknown-none-hermitkernel` | ? |  | HermitCore kernel
 `x86_64-unknown-none-linuxkernel` | * |  | Linux kernel modules
 `x86_64-unknown-openbsd` | ✓ | ✓ | 64-bit OpenBSD
diff --git a/src/doc/rustc/src/platform-support/x86_64-unknown-none.md b/src/doc/rustc/src/platform-support/x86_64-unknown-none.md
new file mode 100644
index 0000000000000..967956b3c3174
--- /dev/null
+++ b/src/doc/rustc/src/platform-support/x86_64-unknown-none.md
@@ -0,0 +1,76 @@
+# `x86_64-unknown-none`
+
+**Tier: 3**
+
+Freestanding/bare-metal x86-64 binaries in ELF format: firmware, kernels, etc.
+
+## Target maintainers
+
+Harald Hoyer <harald@profian.com>, https://github.com/haraldh
+Mike Leany, https://github.com/mikeleany
+
+## Requirements
+
+This target is cross-compiled. There is no support for `std`. There is no
+default allocator, but it's possible to use `alloc` by supplying an allocator.
+
+By default, Rust code generated for this target does not use any vector or
+floating-point registers (e.g. SSE, AVX). This allows the generated code to run
+in environments, such as kernels, which may need to avoid the use of such
+registers or which may have special considerations about the use of such
+registers (e.g. saving and restoring them to avoid breaking userspace code
+using the same registers). You can change code generation to use additional CPU
+features via the `-C target-feature=` codegen options to rustc, or via the
+`#[target_feature]` mechanism within Rust code.
+
+By default, code generated with this target should run on any `x86_64`
+hardware; enabling additional target features may raise this baseline.
+
+Code generated with this target will use the `kernel` code model by default.
+You can change this using the `-C code-model=` option to rustc.
+
+On `x86_64-unknown-none`, `extern "C"` uses the [standard System V calling
+convention](https://gitlab.com/x86-psABIs/x86-64-ABI), without red zones.
+
+This target generated binaries in the ELF format. Any alternate formats or
+special considerations for binary layout will require linker options or linker
+scripts.
+
+## Building the target
+
+You can build Rust with support for the target by adding it to the `target`
+list in `config.toml`:
+
+```toml
+[build]
+build-stage = 1
+target = ["x86_64-unknown-none"]
+```
+
+## Building Rust programs
+
+Rust does not yet ship pre-compiled artifacts for this target. To compile for
+this target, you will either need to build Rust with the target enabled (see
+"Building the target" above), or build your own copy of `core` by using
+`build-std` or similar.
+
+## Testing
+
+As `x86_64-unknown-none` supports a variety of different environments and does
+not support `std`, this target does not support running the Rust testsuite.
+
+## Cross-compilation toolchains and C code
+
+If you want to compile C code along with Rust (such as for Rust crates with C
+dependencies), you will need an appropriate `x86_64` toolchain.
+
+Rust *may* be able to use an `x86_64-linux-gnu-` toolchain with appropriate
+standalone flags to build for this toolchain (depending on the assumptions of
+that toolchain, see below), or you may wish to use a separate
+`x86_64-unknown-none` (or `x86_64-elf-`) toolchain.
+
+On some `x86_64` hosts that use ELF binaries, you *may* be able to use the host
+C toolchain, if it does not introduce assumptions about the host environment
+that don't match the expectations of a standalone environment. Otherwise, you
+may need a separate toolchain for standalone/freestanding development, just as
+when cross-compiling from a non-`x86_64` platform.

From 8b6764c4ef111918211029f91964df8ab5d46258 Mon Sep 17 00:00:00 2001
From: Mike Leany <55358344+mikeleany@users.noreply.github.com>
Date: Sun, 19 Sep 2021 15:50:54 -0600
Subject: [PATCH 11/15] Fix build errors.

---
 compiler/rustc_target/src/spec/x86_64_unknown_none.rs | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/compiler/rustc_target/src/spec/x86_64_unknown_none.rs b/compiler/rustc_target/src/spec/x86_64_unknown_none.rs
index b460ea1c29b55..89ed0ea532740 100644
--- a/compiler/rustc_target/src/spec/x86_64_unknown_none.rs
+++ b/compiler/rustc_target/src/spec/x86_64_unknown_none.rs
@@ -4,7 +4,10 @@
 // `target-cpu` compiler flags to opt-in more hardware-specific
 // features.
 
-use super::{CodeModel, LinkerFlavor, LldFlavor, PanicStrategy, Target, TargetOptions};
+use super::{
+    CodeModel, LinkerFlavor, LldFlavor, PanicStrategy, RelocModel, RelroLevel, StackProbeType,
+    Target, TargetOptions,
+};
 
 pub fn target() -> Target {
     let opts = TargetOptions {

From 3b854cf82d28f02108d871133fabfa37ab0ebeb7 Mon Sep 17 00:00:00 2001
From: Mike Leany <55358344+mikeleany@users.noreply.github.com>
Date: Sun, 19 Sep 2021 17:03:54 -0600
Subject: [PATCH 12/15] Documentation fixes.

Fix broken link to target documentation.

Also fix formatting of developer list.
---
 src/doc/rustc/src/SUMMARY.md                              | 1 +
 src/doc/rustc/src/platform-support/x86_64-unknown-none.md | 4 ++--
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/doc/rustc/src/SUMMARY.md b/src/doc/rustc/src/SUMMARY.md
index 8c41835183797..c251425d1b7ad 100644
--- a/src/doc/rustc/src/SUMMARY.md
+++ b/src/doc/rustc/src/SUMMARY.md
@@ -15,6 +15,7 @@
 - [Platform Support](platform-support.md)
     - [aarch64-apple-ios-sim](platform-support/aarch64-apple-ios-sim.md)
     - [\*-kmc-solid_\*](platform-support/kmc-solid.md)
+    - [x86_64-unknown-none](platform-support/x86_64-unknown-none.md)
 - [Target Tier Policy](target-tier-policy.md)
 - [Targets](targets/index.md)
     - [Built-in Targets](targets/built-in.md)
diff --git a/src/doc/rustc/src/platform-support/x86_64-unknown-none.md b/src/doc/rustc/src/platform-support/x86_64-unknown-none.md
index 967956b3c3174..b56e0e03f998b 100644
--- a/src/doc/rustc/src/platform-support/x86_64-unknown-none.md
+++ b/src/doc/rustc/src/platform-support/x86_64-unknown-none.md
@@ -6,8 +6,8 @@ Freestanding/bare-metal x86-64 binaries in ELF format: firmware, kernels, etc.
 
 ## Target maintainers
 
-Harald Hoyer <harald@profian.com>, https://github.com/haraldh
-Mike Leany, https://github.com/mikeleany
+- Harald Hoyer <harald@profian.com>, https://github.com/haraldh
+- Mike Leany, https://github.com/mikeleany
 
 ## Requirements
 

From 9704a837be2d0a9b4537edfdd8650670162d9e3b Mon Sep 17 00:00:00 2001
From: Josh Triplett <josh@joshtriplett.org>
Date: Wed, 22 Sep 2021 14:01:27 -0700
Subject: [PATCH 13/15] Unlinkify email address to satisfy linkchecker

The linkchecker doesn't seem happy with links to email addresses.
---
 src/doc/rustc/src/platform-support/x86_64-unknown-none.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/doc/rustc/src/platform-support/x86_64-unknown-none.md b/src/doc/rustc/src/platform-support/x86_64-unknown-none.md
index b56e0e03f998b..afcc48003b936 100644
--- a/src/doc/rustc/src/platform-support/x86_64-unknown-none.md
+++ b/src/doc/rustc/src/platform-support/x86_64-unknown-none.md
@@ -6,7 +6,7 @@ Freestanding/bare-metal x86-64 binaries in ELF format: firmware, kernels, etc.
 
 ## Target maintainers
 
-- Harald Hoyer <harald@profian.com>, https://github.com/haraldh
+- Harald Hoyer `harald@profian.com`, https://github.com/haraldh
 - Mike Leany, https://github.com/mikeleany
 
 ## Requirements

From 3a1879299e8742e9193569152bef3f997c51e0ea Mon Sep 17 00:00:00 2001
From: Josh Triplett <josh@joshtriplett.org>
Date: Thu, 30 Sep 2021 16:09:29 -0700
Subject: [PATCH 14/15] x86_64-unknown-none: Use position-independent code by
 default

This avoids requiring relocation code, which a bare-metal environment
may not have or want.
---
 compiler/rustc_target/src/spec/aarch64_unknown_none.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/compiler/rustc_target/src/spec/aarch64_unknown_none.rs b/compiler/rustc_target/src/spec/aarch64_unknown_none.rs
index 9d3652790108c..d74cd9edc59e2 100644
--- a/compiler/rustc_target/src/spec/aarch64_unknown_none.rs
+++ b/compiler/rustc_target/src/spec/aarch64_unknown_none.rs
@@ -14,7 +14,7 @@ pub fn target() -> Target {
         linker: Some("rust-lld".to_owned()),
         features: "+strict-align,+neon,+fp-armv8".to_string(),
         executables: true,
-        relocation_model: RelocModel::Static,
+        relocation_model: RelocModel::Pic,
         disable_redzone: true,
         max_atomic_width: Some(128),
         panic_strategy: PanicStrategy::Abort,

From 11d54dc1c61f74aa4cfa704ed97bf6c853a731e5 Mon Sep 17 00:00:00 2001
From: Mike Leany <55358344+mikeleany@users.noreply.github.com>
Date: Thu, 14 Oct 2021 12:10:20 -0600
Subject: [PATCH 15/15] Fix issue where PIC was added to the wrong target.

Should be for x86_64_unknown_none, but aarch64_unknown_none was inadvertently
updated instead.
---
 compiler/rustc_target/src/spec/aarch64_unknown_none.rs | 2 +-
 compiler/rustc_target/src/spec/x86_64_unknown_none.rs  | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/compiler/rustc_target/src/spec/aarch64_unknown_none.rs b/compiler/rustc_target/src/spec/aarch64_unknown_none.rs
index d74cd9edc59e2..9d3652790108c 100644
--- a/compiler/rustc_target/src/spec/aarch64_unknown_none.rs
+++ b/compiler/rustc_target/src/spec/aarch64_unknown_none.rs
@@ -14,7 +14,7 @@ pub fn target() -> Target {
         linker: Some("rust-lld".to_owned()),
         features: "+strict-align,+neon,+fp-armv8".to_string(),
         executables: true,
-        relocation_model: RelocModel::Pic,
+        relocation_model: RelocModel::Static,
         disable_redzone: true,
         max_atomic_width: Some(128),
         panic_strategy: PanicStrategy::Abort,
diff --git a/compiler/rustc_target/src/spec/x86_64_unknown_none.rs b/compiler/rustc_target/src/spec/x86_64_unknown_none.rs
index 89ed0ea532740..722409dd168ce 100644
--- a/compiler/rustc_target/src/spec/x86_64_unknown_none.rs
+++ b/compiler/rustc_target/src/spec/x86_64_unknown_none.rs
@@ -18,7 +18,7 @@ pub fn target() -> Target {
         position_independent_executables: true,
         static_position_independent_executables: true,
         relro_level: RelroLevel::Full,
-        relocation_model: RelocModel::Static,
+        relocation_model: RelocModel::Pic,
         linker_flavor: LinkerFlavor::Lld(LldFlavor::Ld),
         linker: Some("rust-lld".to_owned()),
         features: