boards/x86: add Intel64 (64-bit long-mode) QEMU target board

Add qemu_x86_long board (with CONFIG_X86_LONGMODE=y) for testing.

This requires adding support to soc/ia32 for long mode (trivial),
and adding a quick 64- to 32-bit ELF conversion before invoking
QEMU, which apparently doesn't like 64-bit kernel files.

Signed-off-by: Charles E. Youse <charles.youse@intel.com>

boards/x86/qemu_x86/Kconfig.board

@@ -6,3 +6,9 @@ config BOARD_QEMU_X86
 	select QEMU_TARGET
 	select CPU_HAS_FPU
 	select HAS_COVERAGE_SUPPORT
+
+config BOARD_QEMU_X86_LONG
+	bool "QEMU x86 (64-bit long mode)"
+	depends on SOC_IA32
+	select QEMU_TARGET
+	select X86_LONGMODE

boards/x86/qemu_x86/Kconfig.defconfig

@@ -2,7 +2,6 @@
 
 if BOARD_QEMU_X86
 
-
 config BUILD_OUTPUT_BIN
         default n
 
@@ -17,3 +16,10 @@ config FLASH_SIMULATOR
 endif
 
 endif # BOARD_QEMU_X86
+
+if BOARD_QEMU_X86_LONG
+
+config BOARD
+	default "qemu_x86_long"
+
+endif # BOARD_QEMU_X86_LONG

boards/x86/qemu_x86/board.cmake

@@ -6,7 +6,13 @@ if(NOT CONFIG_REBOOT)
   set(REBOOT_FLAG -no-reboot)
 endif()
 
-set(QEMU_CPU_TYPE_${ARCH} qemu32,+nx,+pae)
+if(CONFIG_X86_LONGMODE)
+  set(QEMU_binary_suffix x86_64)
+  set(QEMU_CPU_TYPE_${ARCH} qemu64,+x2apic)
+else()
+  set(QEMU_CPU_TYPE_${ARCH} qemu32,+nx,+pae)
+endif()
+
 set(QEMU_FLAGS_${ARCH}
   -m 9
   -cpu ${QEMU_CPU_TYPE_${ARCH}}

boards/x86/qemu_x86/qemu_x86_long.dts

@@ -0,0 +1,10 @@
+/*
+ * Copyright (c) 2019 Intel Corp.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "qemu_x86.dts"
+
+&flash0 {
+	reg = <0x00100000 DT_FLASH_SIZE>;
+};

boards/x86/qemu_x86/qemu_x86_long.yaml

@@ -0,0 +1,13 @@
+identifier: qemu_x86_long
+name: QEMU Emulation for X86 (long mode)
+type: qemu
+arch: x86
+toolchain:
+  - zephyr
+  - xtools
+simulation: qemu
+testing:
+  default: true
+  ignore_tags:
+     - net
+     - bluetooth

boards/x86/qemu_x86/qemu_x86_long_defconfig

@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: Apache-2.0
+
+CONFIG_X86=y
+CONFIG_SOC_IA32=y
+CONFIG_BOARD_QEMU_X86_LONG=y
+CONFIG_CPU_MINUTEIA=y
+CONFIG_HPET_TIMER=y
+CONFIG_HPET_TIMER_IRQ=2
+CONFIG_PIC_DISABLE=y
+CONFIG_LOAPIC=y
+CONFIG_CONSOLE=y
+CONFIG_SERIAL=y
+CONFIG_UART_NS16550=y
+CONFIG_UART_CONSOLE=y
+CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC=25000000
+CONFIG_TEST_RANDOM_GENERATOR=y
+CONFIG_DEBUG_INFO=y

cmake/emu/qemu.cmake

@@ -233,6 +233,17 @@ elseif(QEMU_NET_STACK)
   endif()
 endif(QEMU_PIPE_STACK)
 
+if(CONFIG_X86_LONGMODE)
+  # QEMU doesn't like 64-bit ELF files. Since we don't use any >4GB
+  # addresses, converting it to 32-bit is safe enough for emulation.
+  list(APPEND PRE_QEMU_COMMANDS
+    COMMAND
+    ${CMAKE_OBJCOPY}
+    -O elf32-i386
+    $<TARGET_FILE:${logical_target_for_zephyr_elf}>
+    )
+endif()
+
 if(CONFIG_X86_64)
   set(QEMU_KERNEL_FILE "${CMAKE_BINARY_DIR}/zephyr-qemu.elf")
 endif()

soc/x86/ia32/linker.ld

@@ -45,5 +45,8 @@ MEMORY
     IDT_LIST        : ORIGIN = 0xFFFF1000, LENGTH = 2K
     }
 
+#ifdef CONFIG_X86_LONGMODE
+#include <arch/x86/intel64/linker.ld>
+#else
 #include <arch/x86/ia32/linker.ld>
-
+#endif