Use rust-lld for RV32. Remove riscv git submodule.

.gitmodules

@@ -1,3 +0,0 @@
-[submodule "crate/riscv"]
-	path = crate/riscv
-	url = https://github.com/riscv-and-rust-and-decaf/riscv.git

README.md

@@ -37,7 +37,7 @@ cargo install cargo-xbuild bootimage
 ```
 
 ```bash
-git clone https://github.com/wangrunji0408/RustOS.git --recursive
+git clone https://github.com/wangrunji0408/RustOS.git
 cd RustOS/kernel
 rustup override set nightly-2018-09-18
 make run arch=riscv32|x86_64

crate/riscv

@@ -1 +0,0 @@
-Subproject commit f358204af01f2374ab6ed6ea059f724cd5f2fe6f

kernel/Cargo.lock

@@ -175,6 +175,7 @@ dependencies = [
 [[package]]
 name = "riscv"
 version = "0.3.0"
+source = "git+https://github.com/riscv-and-rust-and-decaf/riscv#f358204af01f2374ab6ed6ea059f724cd5f2fe6f"
 dependencies = [
  "bare-metal 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "bit_field 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -265,7 +266,7 @@ dependencies = [
  "once 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "raw-cpuid 6.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "redox_syscall 0.1.40 (registry+https://github.com/rust-lang/crates.io-index)",
- "riscv 0.3.0",
+ "riscv 0.3.0 (git+https://github.com/riscv-and-rust-and-decaf/riscv)",
  "simple-filesystem 0.0.1 (git+https://github.com/wangrunji0408/SimpleFileSystem-Rust)",
  "spin 0.4.9 (registry+https://github.com/rust-lang/crates.io-index)",
  "uart_16550 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -390,6 +391,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum raw-cpuid 6.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "41219962ecab392f1e68db9e7ebd972800d4045a128cc23462b384e8c312cde1"
 "checksum redox_syscall 0.1.40 (registry+https://github.com/rust-lang/crates.io-index)" = "c214e91d3ecf43e9a4e41e578973adeb14b474f2bee858742d127af75a0112b1"
 "checksum remove_dir_all 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "3488ba1b9a2084d38645c4c08276a1752dcbf2c7130d74f1569681ad5d2799c5"
+"checksum riscv 0.3.0 (git+https://github.com/riscv-and-rust-and-decaf/riscv)" = "<none>"
 "checksum rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "138e3e0acb6c9fb258b19b67cb8abd63c00679d2851805ea151465464fe9030a"
 "checksum semver 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "1d7eb9ef2c18661902cc47e535f9bc51b78acd254da71d375c2f6720d9a40403"
 "checksum semver-parser 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "388a1df253eca08550bef6c72392cfe7c30914bf41df5269b68cbd6ff8f570a3"

kernel/Cargo.toml

@@ -40,7 +40,7 @@ redox_syscall = "0.1"
 uart_16550 = "0.1"
 
 [target.'cfg(target_arch = "riscv32")'.dependencies]
-riscv = { path = "../crate/riscv" }
+riscv = { git = "https://github.com/riscv-and-rust-and-decaf/riscv" }
 bbl = { path = "../crate/bbl" }
 
 [package.metadata.bootimage]

kernel/riscv32-blog_os.json

@@ -9,12 +9,11 @@
   "cpu": "generic-rv32",
   "features": "",
   "max-atomic-width": "32",
-  "linker": "riscv64-unknown-elf-ld",
-  "linker-flavor": "ld",
+  "linker": "rust-lld",
+  "linker-flavor": "ld.lld",
   "pre-link-args": {
-    "ld": [
-      "-Tsrc/arch/riscv32/boot/linker.ld",
-      "-melf32lriscv"
+    "ld.lld": [
+      "-Tsrc/arch/riscv32/boot/linker.ld"
     ]
   },
   "executables": true,

user/riscv32-ucore.json

@@ -9,13 +9,8 @@
   "cpu": "generic-rv32",
   "features": "",
   "max-atomic-width": "32",
-  "linker": "riscv64-unknown-elf-ld",
-  "linker-flavor": "ld",
-  "pre-link-args": {
-    "ld": [
-      "-melf32lriscv"
-    ]
-  },
+  "linker": "rust-lld",
+  "linker-flavor": "ld.lld",
   "executables": true,
   "panic-strategy": "abort",
   "relocation-model": "static",