fix linker script and call main

Author: max-niederman

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

@@ -2,51 +2,53 @@ OUTPUT_FORMAT("elf32-littlearm")
 
 ENTRY(_start)
 
-__cold_start = 0x03800000;
-__cold_length = 0x04800000;
-__cold_end = __cold_start + __cold_length;
+__user_ram_start = 0x03800000;
+__user_ram_length = 0x04800000;
+__user_ram_end = __user_ram_start + __user_ram_length;
 
 MEMORY {
-    COLD : ORIGIN = __cold_start, LENGTH = __cold_length
+    USER_RAM : ORIGIN = __user_ram_start, LENGTH = __user_ram_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;
+__heap_end = __user_ram_end - __stack_length - 64;
 
 SECTIONS {
-    .code_signature : {
+    .code_signature __user_ram_start : {
         KEEP(*(.code_signature))
-        . = __cold_start + 0x20;
-    } > COLD
-    .text : {
-        KEEP(*(.text.boot))
+    } > USER_RAM = 0
+
+    .text __user_ram_start + 0x20 : {
+        *(.text.boot)
         *(.text .text.*)
-    } > COLD
+    } > USER_RAM
+
     .rodata : {
-        __rodata_start = .;
-        *(.rodata1 .rodata1.*)
-        __rodata_end = .;
-    } > COLD
+        *(.rodata .rodata.*)
+    } > USER_RAM
+
     .data : {
         *(.data .data.*)
-        *(.data1 .data1.*)
-    } > COLD
+    } > USER_RAM
+
     .bss : {
         __bss_start = .;
         *(.bss .bss.*)
         __bss_end = .;
-    } > COLD
+    } > USER_RAM
+
     .heap (NOLOAD) : ALIGN(4) {
         __heap_start = .;
         . = __heap_end;
-    } > COLD
+    } > USER_RAM
+
     .stack (NOLOAD) : ALIGN(8) {
-        __stack_end = .;
+        __stack_bottom = .;
         . += __stack_length;
-        __stack_start = .;
-    } > COLD
+        __stack_top = .;
+    } > USER_RAM
+
+    /DISCARD/ : {
+        *(.ARM.exidx)
+    }
 }

library/std/Cargo.toml

@@ -91,7 +91,7 @@ r-efi = { version = "4.5.0", features = ['rustc-dep-of-std'] }
 r-efi-alloc = { version = "1.0.0", features = ['rustc-dep-of-std'] }
 
 [target.'cfg(target_os = "vexos")'.dependencies]
-vex-sdk = { version = "0.16.1", features = ['rustc-dep-of-std'] }
+vex-sdk = { version = "0.17.0", features = ['rustc-dep-of-std'] }
 
 [features]
 backtrace = [

library/std/src/sys/pal/vexos/mod.rs

@@ -15,6 +15,7 @@ pub mod os;
 pub mod pipe;
 #[path = "../unsupported/process.rs"]
 pub mod process;
+#[path = "../unsupported/stdio.rs"]
 pub mod stdio;
 #[path = "../unsupported/thread.rs"]
 pub mod thread;
@@ -23,17 +24,53 @@ pub mod thread_local_key;
 #[path = "../unsupported/time.rs"]
 pub mod time;
 
-#[path = "../unsupported/common.rs"]
-#[deny(unsafe_op_in_unsafe_fn)]
-mod common;
-pub use common::*;
+use crate::arch::asm;
+
+#[cfg(not(test))]
+#[no_mangle]
+#[link_section = ".text.boot"]
+pub unsafe extern "C" fn _start() -> ! {
+    extern "C" {
+        fn main() -> i32;
+    }
+
+    asm!("ldr sp, =__stack_top", options(nostack));
+
+    main();
+
+    abort_internal()
+}
 
 // This function is needed by the panic runtime. The symbol is named in
 // pre-link args for the target specification, so keep that in sync.
 #[cfg(not(test))]
 #[no_mangle]
 // NB. used by both libunwind and libpanic_abort
 pub extern "C" fn __rust_abort() -> ! {
+    abort_internal()
+}
+
+pub unsafe fn init(_argc: isize, _argv: *const *const u8, _sigpipe: u8) {}
+
+pub unsafe fn cleanup() {}
+
+pub fn unsupported<T>() -> crate::io::Result<T> {
+    Err(unsupported_err())
+}
+
+pub fn unsupported_err() -> crate::io::Error {
+    crate::io::Error::UNSUPPORTED_PLATFORM
+}
+
+pub fn is_interrupted(_code: i32) -> bool {
+    false
+}
+
+pub fn decode_error_kind(_code: i32) -> crate::io::ErrorKind {
+    crate::io::ErrorKind::Uncategorized
+}
+
+pub fn abort_internal() -> ! {
     unsafe {
         vex_sdk::vexSystemExitRequest();
     }
@@ -42,3 +79,7 @@ pub extern "C" fn __rust_abort() -> ! {
         crate::hint::spin_loop()
     }
 }
+
+pub fn hashmap_random_keys() -> (u64, u64) {
+    (1, 2)
+}