[libc][uefi] add errno and uefi status conversion

Author: RossComputerGuy

libc/src/__support/OSUtil/uefi/CMakeLists.txt

@@ -3,9 +3,13 @@ add_object_library(
   SRCS
     io.cpp
     exit.cpp
+    error.cpp
   HDRS
     io.h
+    error.h
   DEPENDS
+    libc.include.errno
+    libc.include.limits
     libc.src.__support.common
     libc.src.__support.CPP.string_view
 )

libc/src/__support/OSUtil/uefi/error.cpp

@@ -0,0 +1,88 @@
+//===---------- UEFI implementation of error utils ------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===-------------------------------------------------------------------===//
+
+#include "error.h"
+#include "errno.h"
+#include "limits.h"
+#include "src/__support/macros/config.h"
+
+#define ERROR_BIT (sizeof(size_t) * CHAR_BIT)
+
+namespace LIBC_NAMESPACE_DECL {
+
+static const struct {
+  EFI_STATUS status;
+  int errno;
+} uefi_status_errno_map[] = {
+    {EFI_SUCCESS, 0},
+    {ERROR_BIT | EFI_LOAD_ERROR, EINVAL},
+    {ERROR_BIT | EFI_INVALID_PARAMETER, EINVAL},
+    {ERROR_BIT | EFI_BAD_BUFFER_SIZE, EINVAL},
+    {ERROR_BIT | EFI_NOT_READY, EBUSY},
+    {ERROR_BIT | EFI_DEVICE_ERROR, EIO},
+    {ERROR_BIT | EFI_WRITE_PROTECTED, EPERM},
+    {ERROR_BIT | EFI_OUT_OF_RESOURCES, ENOMEM},
+    {ERROR_BIT | EFI_VOLUME_CORRUPTED, EROFS},
+    {ERROR_BIT | EFI_VOLUME_FULL, ENOSPC},
+    {ERROR_BIT | EFI_NO_MEDIA, ENODEV},
+    {ERROR_BIT | EFI_MEDIA_CHANGED, ENXIO},
+    {ERROR_BIT | EFI_NOT_FOUND, ENOENT},
+    {ERROR_BIT | EFI_ACCESS_DENIED, EACCES},
+    {ERROR_BIT | EFI_NO_RESPONSE, EBUSY},
+    {ERROR_BIT | EFI_NO_MAPPING, ENODEV},
+    {ERROR_BIT | EFI_TIMEOUT, EBUSY},
+    {ERROR_BIT | EFI_NOT_STARTED, EAGAIN},
+    {ERROR_BIT | EFI_ALREADY_STARTED, EINVAL},
+    {ERROR_BIT | EFI_ABORTED, EFAULT},
+    {ERROR_BIT | EFI_ICMP_ERROR, EIO},
+    {ERROR_BIT | EFI_TFTP_ERROR, EIO},
+    {ERROR_BIT | EFI_PROTOCOL_ERROR, EINVAL},
+    {ERROR_BIT | EFI_INCOMPATIBLE_VERSION, EINVAL},
+    {ERROR_BIT | EFI_SECURITY_VIOLATION, EPERM},
+    {ERROR_BIT | EFI_CRC_ERROR, EINVAL},
+    {ERROR_BIT | EFI_END_OF_MEDIA, EPIPE},
+    {ERROR_BIT | EFI_END_OF_FILE, EPIPE},
+    {ERROR_BIT | EFI_INVALID_LANGUAGE, EINVAL},
+    {ERROR_BIT | EFI_COMPROMISED_DATA, EINVAL},
+    {ERROR_BIT | EFI_IP_ADDRESS_CONFLICT, EINVAL},
+    {ERROR_BIT | EFI_HTTP_ERROR, EIO},
+    {EFI_WARN_UNKNOWN_GLYPH, EINVAL},
+    {EFI_WARN_DELETE_FAILURE, EROFS},
+    {EFI_WARN_WRITE_FAILURE, EROFS},
+    {EFI_WARN_BUFFER_TOO_SMALL, E2BIG},
+    {EFI_WARN_STALE_DATA, EINVAL},
+    {EFI_WARN_FILE_SYSTEM, EROFS},
+    {EFI_WARN_RESET_REQUIRED, EINTR},
+};
+
+static constexpr size_t uefi_status_errno_map_length =
+    sizeof(uefi_status_errno_map) / sizeof(uefi_status_errno_map[0]);
+
+int uefi_status_to_errno(EFI_STATUS status) {
+  for (size_t i = 0; i < uefi_status_errno_map_length; i++) {
+    if (uefi_status_errno_map[i].status == status) {
+      return uefi_status_errno_map[i].errno;
+    }
+  }
+
+  // Unknown type
+  __builtin_unreachable();
+}
+
+EFI_STATUS errno_to_uefi_status(int errno) {
+  for (size_t i = 0; i < uefi_status_errno_map_length; i++) {
+    if (uefi_status_errno_map[i].errno == errno) {
+      return uefi_status_errno_map[i].status;
+    }
+  }
+
+  // Unknown type
+  __builtin_unreachable();
+}
+
+} // namespace LIBC_NAMESPACE_DECL

libc/src/__support/OSUtil/uefi/error.h

@@ -0,0 +1,22 @@
+//===---------- UEFI implementation of error utils ------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===-------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC___SUPPORT_OSUTIL_UEFI_ERROR_H
+#define LLVM_LIBC_SRC___SUPPORT_OSUTIL_UEFI_ERROR_H
+
+#include "include/llvm-libc-types/EFI_STATUS.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+int uefi_status_to_errno(EFI_STATUS status);
+EFI_STATUS errno_to_uefi_status(int errno);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC___SUPPORT_OSUTIL_UEFI_ERROR_H

libc/startup/uefi/CMakeLists.txt

@@ -31,7 +31,9 @@ endfunction()
 add_startup_object(
   crt1
   SRCS
-  crt1.cpp
+    crt1.cpp
+  DEPENDS
+    libc.src.__support.OSUtil.uefi.uefi_util
 )
 
 add_custom_target(libc-startup)

libc/startup/uefi/crt1.cpp

@@ -10,6 +10,7 @@
 #include "include/llvm-libc-types/EFI_HANDLE.h"
 #include "include/llvm-libc-types/EFI_STATUS.h"
 #include "include/llvm-libc-types/EFI_SYSTEM_TABLE.h"
+#include "src/__support/OSUtil/uefi/error.h"
 #include "src/__support/macros/config.h"
 
 extern "C" {
@@ -24,9 +25,6 @@ EFI_STATUS EfiMain(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable) {
 
   // TODO: we need the EFI_SHELL_PROTOCOL, malloc, free, and UTF16 -> UTF8
   // conversion.
-  main(0, nullptr, nullptr);
-
-  // TODO: convert the return value of main to EFI_STATUS
-  return EFI_SUCCESS;
+  return LIBC_NAMESPACE::errno_to_uefi_status(main(0, nullptr, nullptr));
 }
 }