Add Sony PlayStation 1 tier 3 target

Author: ayrtonm

compiler/rustc_target/src/spec/mipsel_sony_psx.rs

@@ -0,0 +1,37 @@
+use crate::spec::{cvs, Cc, LinkerFlavor, Lld, PanicStrategy, RelocModel, Target, TargetOptions};
+
+pub fn target() -> Target {
+    Target {
+        llvm_target: "mipsel-sony-psx".into(),
+        pointer_width: 32,
+        data_layout: "e-m:m-p:32:32-i8:8:32-i16:16:32-i64:64-n32-S64".into(),
+        arch: "mips".into(),
+
+        options: TargetOptions {
+            os: "none".into(),
+            env: "psx".into(),
+            vendor: "sony".into(),
+            linker_flavor: LinkerFlavor::Gnu(Cc::No, Lld::Yes),
+            cpu: "mips1".into(),
+            executables: true,
+            linker: Some("rust-lld".into()),
+            relocation_model: RelocModel::Static,
+            exe_suffix: ".exe".into(),
+
+            // PSX doesn't natively support floats.
+            features: "+soft-float".into(),
+
+            // This should be 16 bits, but LLVM incorrectly tries emitting MIPS-II SYNC instructions
+            // for atomic loads and stores. This crashes rustc so we have to disable the Atomic* API
+            // until this is fixed upstream. See https://reviews.llvm.org/D122427#3420144 for more
+            // info.
+            max_atomic_width: Some(0),
+
+            // PSX does not support trap-on-condition instructions.
+            llvm_args: cvs!["-mno-check-zero-division"],
+            llvm_abiname: "o32".into(),
+            panic_strategy: PanicStrategy::Abort,
+            ..Default::default()
+        },
+    }
+}

compiler/rustc_target/src/spec/mod.rs

@@ -1222,6 +1222,7 @@ supported_targets! {
     ("armv7a-kmc-solid_asp3-eabihf", armv7a_kmc_solid_asp3_eabihf),
 
     ("mipsel-sony-psp", mipsel_sony_psp),
+    ("mipsel-sony-psx", mipsel_sony_psx),
     ("mipsel-unknown-none", mipsel_unknown_none),
     ("thumbv4t-none-eabi", thumbv4t_none_eabi),
     ("armv4t-none-eabi", armv4t_none_eabi),

src/doc/rustc/src/SUMMARY.md

@@ -29,6 +29,7 @@
     - [\*-kmc-solid_\*](platform-support/kmc-solid.md)
     - [m68k-unknown-linux-gnu](platform-support/m68k-unknown-linux-gnu.md)
     - [mips64-openwrt-linux-musl](platform-support/mips64-openwrt-linux-musl.md)
+    - [mipsel-sony-psx](platform-support/mipsel-sony-psx.md)
     - [nvptx64-nvidia-cuda](platform-support/nvptx64-nvidia-cuda.md)
     - [riscv32imac-unknown-xous-elf](platform-support/riscv32imac-unknown-xous-elf.md)
     - [*-pc-windows-gnullvm](platform-support/pc-windows-gnullvm.md)

src/doc/rustc/src/platform-support.md

@@ -260,6 +260,7 @@ target | std | host | notes
 `mips-unknown-linux-uclibc` | ✓ |  | MIPS Linux with uClibc
 [`mips64-openwrt-linux-musl`](platform-support/mips64-openwrt-linux-musl.md) | ? |  | MIPS64 for OpenWrt Linux MUSL
 `mipsel-sony-psp` | * |  | MIPS (LE) Sony PlayStation Portable (PSP)
+[`mipsel-sony-psx`](platform-support/mipsel-sony-psx.md) | * |  | MIPS (LE) Sony PlayStation 1 (PSX)
 `mipsel-unknown-linux-uclibc` | ✓ |  | MIPS (LE) Linux with uClibc
 `mipsel-unknown-none` | * |  | Bare MIPS (LE) softfloat
 `mipsisa32r6-unknown-linux-gnu` | ? |  |

src/doc/rustc/src/platform-support/mipsel-sony-psx.md

@@ -0,0 +1,49 @@
+# mipsel-sony-psx
+
+**Tier: 3**
+
+Sony PlayStation 1 (psx)
+
+## Designated Developer
+
+* [@ayrtonm](https://github.com/ayrtonm)
+
+## Requirements
+
+This target is cross-compiled.
+It has no special requirements for the host.
+
+## Building
+
+The target can be built by enabling it for a `rustc` build:
+
+```toml
+[build]
+build-stage = 1
+target = ["mipsel-sony-psx"]
+```
+
+## Cross-compilation
+
+This target can be cross-compiled from any host.
+
+## Testing
+
+Currently there is no support to run the rustc test suite for this target.
+
+## Building Rust programs
+
+Since it is Tier 3, rust doesn't ship pre-compiled artifacts for this target.
+
+Just use the `build-std` nightly cargo feature to build the `core` and `alloc` libraries:
+```shell
+cargo build -Zbuild-std=core,alloc --target mipsel-sony-psx
+```
+
+The command above generates an ELF. To generate binaries in the PSEXE format that emulators run, you can use [cargo-psx](https://github.com/ayrtonm/psx-sdk-rs#readme):
+
+```shell
+cargo psx build
+```
+
+or use `-Clink-arg=--oformat=binary` to produce a flat binary.