build: update to support building under a hosted cross-compiler

CMakeLists.txt

@@ -1,10 +1,6 @@
 cmake_minimum_required(VERSION 3.31)
 project(magenta C ASM)
 
-if (NOT BUILD_TOOLS_DIR)
-	message(FATAL_ERROR "No build tools directory specified. Please run build.sh")
-endif ()
-
 set(CMAKE_C_STANDARD 17)
 
 set(kernel_arch x86_64)
@@ -85,3 +81,5 @@ target_include_directories(magenta_debug PRIVATE
 	libc/include
 	libmagenta/include
 	arch/${kernel_arch}/include)
+
+install(TARGETS ${kernel_exe_name} DESTINATION boot)

arch/x86_64/thread.c

@@ -93,6 +93,8 @@ kern_status_t ml_thread_clone_user_context(
 	memcpy(regs, src_regs, sizeof *regs);
 
 	regs->rax = return_value;
+	regs->ss = 0x1b;
+	regs->cs = 0x23;
 
 	dest_ml->tr_fsbase = src_ml->tr_fsbase;
 	dest_ml->tr_gsbase = src_ml->tr_gsbase;

debug/CMakeLists.txt

@@ -2,3 +2,4 @@ file(GLOB sources *.c *.h include/magenta/debug/*.h)
 
 add_library(magenta_debug STATIC ${sources})
 target_include_directories(magenta_debug PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/include)
+target_compile_options(magenta_debug PRIVATE -ffreestanding -nostdlib)

ds/ringbuf.c

@@ -286,8 +286,8 @@ kern_status_t ringbuf_write(
 	kern_status_t status = KERN_OK;
 
 	while (remaining > 0) {
-		void *dest;
-		size_t available;
+		void *dest = NULL;
+		size_t available = 0;
 		wait_for_capacity(buf, irq_flags);
 
 		status = ringbuf_open_write_buffer(buf, &dest, &available);

libmagenta/CMakeLists.txt

@@ -1,4 +1,9 @@
-file(GLOB headers ${CMAKE_CURRENT_SOURCE_DIR}/include/magenta/*.h)
+cmake_minimum_required(VERSION 3.31)
+project(libmagenta C ASM)
+
+file(GLOB headers
+	${CMAKE_CURRENT_SOURCE_DIR}/include/magenta/*.h
+	${CMAKE_CURRENT_SOURCE_DIR}/include-user/magenta/*.h)
 file(GLOB asm_sources
 	${CMAKE_CURRENT_SOURCE_DIR}/arch/${CMAKE_SYSTEM_PROCESSOR}/*.S)
 
@@ -6,7 +11,14 @@ set(public_include_dirs
 	${CMAKE_CURRENT_SOURCE_DIR}/include
 	${CMAKE_CURRENT_SOURCE_DIR}/include-user)
 
-add_library(libmagenta STATIC ${asm_sources})
+add_library(libmagenta STATIC ${asm_sources} ${headers})
 target_include_directories(libmagenta PUBLIC
 	${CMAKE_CURRENT_SOURCE_DIR}/include
 	${CMAKE_CURRENT_SOURCE_DIR}/include-user)
+target_compile_options(libmagenta PRIVATE -ffreestanding -nostdlib)
+
+set_target_properties(libmagenta PROPERTIES
+	PREFIX "")
+
+install(TARGETS libmagenta)
+install(FILES ${headers} DESTINATION include/magenta)

tools/e64patch/CMakeLists.txt

@@ -1,3 +1,5 @@
 file(GLOB sources *.c *.h)
 
 add_executable(e64patch ${sources})
+
+install(TARGETS e64patch)