add armv7a-vex-v5 target

Author: max-niederman

compiler/rustc_target/src/spec/mod.rs

@@ -1913,6 +1913,8 @@ supported_targets! {
 
     ("armv7-sony-vita-newlibeabihf", armv7_sony_vita_newlibeabihf),
 
+    ("armv7a-vex-v5", armv7a_vex_v5),
+
     ("armv7-unknown-linux-uclibceabi", armv7_unknown_linux_uclibceabi),
     ("armv7-unknown-linux-uclibceabihf", armv7_unknown_linux_uclibceabihf),
 

compiler/rustc_target/src/spec/targets/armv7a_vex_v5.rs

@@ -0,0 +1,34 @@
+use crate::spec::{Cc, LinkerFlavor, Lld, PanicStrategy, RelocModel, Target, TargetOptions};
+
+const LINK_SCRIPT: &str = include_str!("./armv7a_vex_v5_linker_script.ld");
+
+pub(crate) fn target() -> Target {
+    Target {
+        llvm_target: "armv7a-none-eabi".into(),
+        metadata: crate::spec::TargetMetadata {
+            description: None,
+            tier: None,
+            host_tools: None,
+            std: None,
+        },
+        pointer_width: 32,
+        data_layout: "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64".into(),
+        arch: "arm".into(),
+        options: TargetOptions {
+            abi: "eabi".into(),
+            linker_flavor: LinkerFlavor::Gnu(Cc::No, Lld::Yes),
+            linker: Some("rust-lld".into()),
+            link_script: Some(LINK_SCRIPT.into()),
+            features: "+v7,+thumb2,+soft-float,-neon,+strict-align".into(),
+            relocation_model: RelocModel::Static,
+            disable_redzone: true,
+            max_atomic_width: Some(64),
+            panic_strategy: PanicStrategy::Abort,
+            emit_debug_gdb_scripts: false,
+            c_enum_min_bits: Some(8),
+            os: "vexos".into(),
+            vendor: "vex".into(),
+            ..Default::default()
+        },
+    }
+}

compiler/rustc_target/src/spec/targets/armv7a_vex_v5_linker_script.ld

@@ -0,0 +1,52 @@
+OUTPUT_FORMAT("elf32-littlearm")
+
+ENTRY(_start)
+
+__cold_start = 0x03800000;
+__cold_length = 0x04800000;
+__cold_end = __cold_start + __cold_length;
+
+MEMORY {
+    COLD : ORIGIN = __cold_start, LENGTH = __cold_length
+}
+
+__stack_length = 0x400000;
+/*
+I'm not sure why subtracting anything is necessary, but it fixes memory permission errors.
+0x1000 is an arbitrary number that works.
+*/
+__heap_end = __cold_end - __stack_length - 0x1000;
+
+SECTIONS {
+    .code_signature {
+        KEEP(*(.code_signature))
+        . = __cold_start + 0x20;
+    } > COLD
+    .text : {
+        KEEP(*(.text.boot))
+        *(.text .text.*)
+    } > COLD
+    .rodata : {
+        __rodata_start = .;
+        *(.rodata1 .rodata1.*)
+        __rodata_end = .;
+    } > COLD
+    .data : {
+        *(.data .data.*)
+        *(.data1 .data1.*)
+    } > COLD
+    .bss : {
+        __bss_start = .;
+        *(.bss .bss.*)
+        __bss_end = .;
+    } > COLD
+    .heap (NOLOAD) : ALIGN(4) {
+        __heap_start = .;
+        . = __heap_end;
+    } > COLD
+    .stack (NOLOAD) : ALIGN(8) {
+        __stack_end = .;
+        . += __stack_length;
+        __stack_start = .;
+    } > COLD
+}