RISC-V support

Author: philipc

GccBase.lds

@@ -0,0 +1,75 @@
+/** @file
+
+  Unified linker script for GCC based builds
+
+  Copyright (c) 2010 - 2015, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2015, Linaro Ltd. All rights reserved.<BR>
+  (C) Copyright 2016 Hewlett Packard Enterprise Development LP<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+SECTIONS {
+
+  /*
+   * The PE/COFF binary consists of DOS and PE/COFF headers, and a sequence of
+   * section headers adding up to PECOFF_HEADER_SIZE bytes (which differs
+   * between 32-bit and 64-bit builds). The actual start of the .text section
+   * will be rounded up based on its actual alignment.
+   */
+  . = PECOFF_HEADER_SIZE;
+
+  .text : ALIGN(COMMONPAGESIZE) {
+    *(.text .text.* .stub .gnu.linkonce.t.*)
+    *(.rodata .rodata.* .gnu.linkonce.r.*)
+    *(.got .got.*)
+
+    /*
+     * The contents of AutoGen.c files are mostly constant from the POV of the
+     * program, but most of it ends up in .data or .bss by default since few of
+     * the variable definitions that get emitted are declared as CONST.
+     * Unfortunately, we cannot pull it into the .text section entirely, since
+     * patchable PCDs are also emitted here, but we can at least move all of the
+     * emitted GUIDs here.
+     */
+    *:AutoGen.obj(.data.g*Guid)
+  }
+
+  /*
+   * The alignment of the .data section should be less than or equal to the
+   * alignment of the .text section. This ensures that the relative offset
+   * between these sections is the same in the ELF and the PE/COFF versions of
+   * this binary.
+   */
+  .data ALIGN(ALIGNOF(.text)) : ALIGN(COMMONPAGESIZE) {
+    *(.data .data.* .gnu.linkonce.d.*)
+    *(.bss .bss.*)
+  }
+
+  .rela (INFO) : {
+    *(.rela .rela.*)
+  }
+
+  .hii : ALIGN(COMMONPAGESIZE) {
+    KEEP (*(.hii))
+  }
+
+  /*
+   * Retain the GNU build id but in a non-allocatable section so GenFw
+   * does not copy it into the PE/COFF image.
+   */
+  .build-id (INFO) : { *(.note.gnu.build-id) }
+
+  /DISCARD/ : {
+    *(.eh_frame)
+    *(.note.GNU-stack)
+    *(.gnu_debuglink)
+    *(.interp)
+    *(.dynsym)
+    *(.dynstr)
+    *(.dynamic)
+    *(.hash .gnu.hash)
+    *(.comment)
+  }
+}

build.py

@@ -37,6 +37,7 @@
     'qemu_binary': {
         'x86_64': 'qemu-system-x86_64',
         'aarch64': 'qemu-system-aarch64',
+        'riscv64': 'qemu-system-riscv64',
     },
     # Path to directory containing `OVMF_{CODE/VARS}.fd` (for x86_64),
     # or `*-pflash.raw` (for AArch64).
@@ -61,6 +62,14 @@ def get_target_triple():
     arch = SETTINGS['arch']
     return f'{arch}-unknown-uefi'
 
+def get_target_triple_option():
+    arch = SETTINGS['arch']
+    if arch == 'riscv64':
+        triple = 'riscv64-unknown-uefi.json'
+    else:
+        triple = get_target_triple()
+    return triple
+
 def build_dir():
     'Returns the directory where Cargo places the build artifacts'
     return target_dir() / get_target_triple() / SETTINGS['config']
@@ -72,7 +81,7 @@ def esp_dir():
 def run_tool(tool, *flags):
     'Runs cargo-<tool> with certain arguments.'
 
-    target = get_target_triple()
+    target = get_target_triple_option()
     cmd = ['cargo', tool, '--target', target, *flags]
 
     if SETTINGS['verbose']:
@@ -107,14 +116,23 @@ def build(*test_flags):
     # Copy the built test runner file to the right directory for running tests.
     built_file = build_dir() / 'uefi-test-runner.efi'
 
+    arch = SETTINGS['arch']
+    if arch == 'riscv64':
+        sp.run([
+            'elftoefi',
+            build_dir() / 'uefi-test-runner',
+            built_file,
+        ], check=True)
+
     boot_dir = esp_dir() / 'EFI' / 'Boot'
     boot_dir.mkdir(parents=True, exist_ok=True)
 
-    arch = SETTINGS['arch']
     if arch == 'x86_64':
         output_file = boot_dir / 'BootX64.efi'
     elif arch == 'aarch64':
         output_file = boot_dir / 'BootAA64.efi'
+    elif arch == 'riscv64':
+        output_file = boot_dir / 'BootRV64.efi'
 
     shutil.copy2(built_file, output_file)
 
@@ -302,6 +320,11 @@ def run_qemu():
             # A72 is a very generic 64-bit ARM CPU in the wild
             '-cpu', 'cortex-a72',
         ])
+    elif arch == 'riscv64':
+        qemu_flags.extend([
+            '-machine', 'virt',
+            '-cpu', 'rv64',
+        ])
     else:
         raise NotImplementedError('Unknown arch')
 
@@ -434,7 +457,7 @@ def main():
                         choices=['build', 'run', 'doc', 'clippy', 'test'])
 
     parser.add_argument('--target', help='target to build for (default: %(default)s)', type=str,
-                        choices=['x86_64', 'aarch64'], default='x86_64')
+                        choices=['x86_64', 'aarch64', 'riscv64'], default='x86_64')
 
     parser.add_argument('--verbose', '-v', help='print commands before executing them',
                         action='store_true')

riscv64-unknown-uefi.json

@@ -0,0 +1,39 @@
+{
+  "abi-return-struct-as-int": true,
+  "allows-weak-linkage": false,
+  "arch": "riscv64",
+  "code-model": "medium",
+  "cpu": "generic-rv64",
+  "data-layout": "e-m:e-p:64:64-i64:64-i128:128-n64-S128",
+  "disable-redzone": true,
+  "eh-frame-header": false,
+  "emit-debug-gdb-scripts": false,
+  "executables": true,
+  "features": "+m,+a,+f,+d,+c",
+  "linker": "rust-lld",
+  "linker-flavor": "ld.lld",
+  "llvm-target": "riscv64",
+  "max-atomic-width": 64,
+  "os": "uefi",
+  "panic-strategy": "abort",
+  "pre-link-args": {
+    "ld.lld": [
+      "--entry", "efi_main",
+      "--nmagic",
+      "--emit-relocs",
+      "--no-relax",
+      "-z", "common-page-size=0x40",
+      "--defsym=COMMONPAGESIZE=0x40",
+      "--defsym=PECOFF_HEADER_SIZE=0x220",
+      "-TGccBase.lds"
+    ]
+  },
+  "singlethread": true,
+  "split-debuginfo": "packed",
+  "stack-probes": {
+    "kind": "call"
+  },
+  "target-c-int-width": "32",
+  "target-endian": "little",
+  "target-pointer-width": "64"
+}