boards: qemu_x86_tiny: enable support for coverage

This adds the bits so that we can use qemu_x86_tiny for
coverage, as this is currently the only board that can do
demand paging.

This uses the board revision as a way to specify the RAM
size as coverage requires more memory available to store
the coverage data. By piggybacking onto board revision,
this avoids adding another board config just for coverage.

Signed-off-by: Daniel Leung <daniel.leung@intel.com>

boards/x86/qemu_x86/Kconfig.board

@@ -26,3 +26,4 @@ config BOARD_QEMU_X86_TINY
 	depends on SOC_IA32
 	select QEMU_TARGET
 	select CPU_HAS_FPU
+	select HAS_COVERAGE_SUPPORT

boards/x86/qemu_x86/qemu_x86_tiny.ld

@@ -189,6 +189,7 @@ MEMORY
 	LIB_ZEPHYR_OBJECT_FILE_IN_SECT(lsect, cbprintf_complete)	\
 	LIB_ZEPHYR_OBJECT_FILE_IN_SECT(lsect, cbprintf_nano)		\
 	LIB_ZEPHYR_OBJECT_FILE_IN_SECT(lsect, configs)			\
+	LIB_ZEPHYR_OBJECT_FILE_IN_SECT(lsect, coverage)			\
 	LIB_ZEPHYR_OBJECT_FILE_IN_SECT(lsect, heap)			\
 	LIB_ZEPHYR_OBJECT_FILE_IN_SECT(lsect, heap-validate)		\
 	LIB_ZEPHYR_OBJECT_FILE_IN_SECT(lsect, mutex)			\
@@ -198,6 +199,8 @@ MEMORY
 	LIB_ZEPHYR_OBJECT_FILE_IN_SECT(lsect, stdout_console)		\
 	LIB_ZEPHYR_OBJECT_FILE_IN_SECT(lsect, sys_clock_init)		\
 	LIB_ZEPHYR_OBJECT_FILE_IN_SECT(lsect, rb)			\
+	LIB_ZEPHYR_OBJECT_FILE_IN_SECT(lsect, tracing_none)		\
+	LIB_ZEPHYR_OBJECT_FILE_IN_SECT(lsect, tracing_tracking)		\
 	LIB_ZEPHYR_OBJECT_FILE_IN_SECT(lsect, thread_entry)		\
 	LIB_ZEPHYR_OBJECT_FILE_IN_SECT(lsect, work_q)
 
@@ -395,6 +398,10 @@ SECTIONS
 		*libc.a:(.text.*)
 #endif /* CONFIG_NEWLIB_LIBC */
 
+#ifdef CONFIG_COVERAGE
+		*(.text._sub_I_00100_0)
+#endif
+
 		ZEPHYR_KERNEL_FUNCS_IN_SECT
 
 #include <zephyr/linker/kobject-text.ld>
@@ -436,6 +443,7 @@ SECTIONS
 #endif /* CONFIG_NEWLIB_LIBC */
 
 #include <snippets-rodata.ld>
+#include <snippets-pinned-rodata.ld>
 
 #include <zephyr/linker/kobject-rom.ld>
 
@@ -466,14 +474,34 @@ SECTIONS
 		LIB_DRIVERS_IN_SECT(data)
 		LIB_SUBSYS_LOGGING_IN_SECT(data)
 
+#ifdef CONFIG_COVERAGE
+		*(.data.__gcov_.*)
+
+		/*
+		 * This is for the struct gcov_info for
+		 * various functions.
+		 */
+		*(.data..LPBX*)
+#endif
+
 	} GROUP_DATA_LINK_IN(RAMABLE_REGION, ROMABLE_REGION)
 
 #include <zephyr/linker/common-ram.ld>
 #include <zephyr/arch/x86/pagetables.ld>
 #include <zephyr/linker/kobject-data.ld>
 
+/* Located in generated directory. This file is populated by the
+ * zephyr_linker_sources() Cmake function.
+ */
+#include <snippets-pinned-data-sections.ld>
+
 	lnkr_pinned_data_end = .;
 
+/* Located in generated directory. This file is populated by the
+ * zephyr_linker_sources() Cmake function.
+ */
+#include <snippets-pinned-ram-sections.ld>
+
 	SECTION_PROLOGUE(pinned.bss, (NOLOAD),)
 	{
 		. = ALIGN(4);
@@ -491,6 +519,10 @@ SECTIONS
 		LIB_DRIVERS_IN_SECT(bss)
 		LIB_SUBSYS_LOGGING_IN_SECT(bss)
 
+#ifdef CONFIG_COVERAGE
+		*(.bss.__gcov0.*)
+#endif
+
 		lnkr_pinned_bss_end = .;
 	} GROUP_NOLOAD_LINK_IN(RAMABLE_REGION, ROMABLE_REGION)
 

boards/x86/qemu_x86/qemu_x86_tiny_768.conf

@@ -0,0 +1,5 @@
+# Copyright (c) 2022 Intel Corporation.
+# SPDX-License-Identifier: Apache-2.0
+
+# Enable coverage regardless since this config for coverage only.
+CONFIG_COVERAGE=y

boards/x86/qemu_x86/qemu_x86_tiny_768.overlay

@@ -0,0 +1,10 @@
+/*
+ * Copyright (c) 2022 Intel Corporation
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/* Override with 768KB DRAM */
+&dram0 {
+	reg = < 0x100000 DT_SIZE_K(768) >;
+};

boards/x86/qemu_x86/revision.cmake

@@ -0,0 +1,5 @@
+# Copyright (c) 2022 Intel Corporation.
+# SPDX-License-Identifier: Apache-2.0
+
+# We can't really do board_check_revision() here
+# as it will apply to all qemu_x86* boards.

tests/kernel/mbox/mbox_api/boards/qemu_x86_tiny_768.conf

@@ -0,0 +1,5 @@
+# Copyright (c) 2022 Intel Corporation
+# SPDX-License-Identifier: Apache-2.0
+
+# Need quite some space for coverage.
+CONFIG_TEST_EXTRA_STACK_SIZE=1024

tests/kernel/mem_protect/mem_map/boards/qemu_x86_tiny_768.overlay

@@ -0,0 +1,3 @@
+&dram0 {
+	reg = < 0x100000 0x100000 >;
+};

tests/kernel/mem_protect/stackprot/boards/qemu_x86_tiny_768.conf

@@ -0,0 +1,5 @@
+# Copyright 2022 Intel Corporation
+# SPDX-License-Identifier: Apache-2.0
+
+# This is needed for coverage.
+CONFIG_MAIN_STACK_SIZE=4096