[boot] Improve non-printing error handling

Add an implicit __LINE__ to the try_or_raise macro, which gets set in
r11 on cpu_assert. Also made status lines smarter about when to call
cpu_assert.

src/boot/error.cpp

@@ -35,27 +35,28 @@ message(uefi::status status)
 }
 
 [[ noreturn ]] static void
-cpu_assert(uefi::status s, const wchar_t *message)
+cpu_assert(uefi::status s, const wchar_t *message, size_t line)
 {
 	asm volatile (
 		"movq $0xeeeeeeebadbadbad, %%r8;"
 		"movq %0, %%r9;"
 		"movq %1, %%r10;"
+		"movq %2, %%r11;"
 		"movq $0, %%rdx;"
 		"divq %%rdx;"
 		:
-		: "r"((uint64_t)s), "r"(message)
+		: "r"((uint64_t)s), "r"(message), "r"(line)
 		: "rax", "rdx", "r8", "r9", "r10");
 	while (1) asm("hlt");
 }
 
 [[ noreturn ]] void
-raise(uefi::status status, const wchar_t *message)
+raise(uefi::status status, const wchar_t *message, size_t line)
 {
 	if(status_line::fail(message, status))
 		while (1) asm("hlt");
 	else
-		cpu_assert(status, message);
+		cpu_assert(status, message, line);
 }
 
 

src/boot/error.h

@@ -12,7 +12,7 @@ class console;
 namespace error {
 
 /// Halt or exit the program with the given error status/message
-[[ noreturn ]] void raise(uefi::status status, const wchar_t *message);
+[[ noreturn ]] void raise(uefi::status status, const wchar_t *message, size_t line = 0);
 
 const wchar_t * message(uefi::status status);
 
@@ -28,6 +28,6 @@ void debug_break();
 #define try_or_raise(s, m) \
 	do { \
 		uefi::status _s = (s); \
-		if (uefi::is_error(_s)) ::boot::error::raise(_s, (m)); \
+		if (uefi::is_error(_s)) ::boot::error::raise(_s, (m), __LINE__); \
 	} while(0)
 

src/boot/main.cpp

@@ -163,7 +163,7 @@ uefi_preboot(uefi::handle image, uefi::system_table *st)
 memory::efi_mem_map
 uefi_exit(args::header *args, uefi::handle image, uefi::boot_services *bs)
 {
-	status_line status {L"Exiting UEFI"};
+	status_line status {L"Exiting UEFI", nullptr, false};
 
 	memory::efi_mem_map map =
 		memory::build_kernel_mem_map(args, bs);

src/boot/paging.cpp

@@ -118,7 +118,7 @@ private:
 
 		if (!(parent_ent & 1)) {
 			if (!m_cache_count--)
-				error::raise(uefi::status::out_of_resources, L"Page table cache empty");
+				error::raise(uefi::status::out_of_resources, L"Page table cache empty", 0x7ab1e5);
 
 			page_table *table = reinterpret_cast<page_table*>(m_page_cache);
 			m_page_cache = offset_ptr<void>(m_page_cache, page_size);

src/boot/status.cpp

@@ -30,7 +30,8 @@ status *status::s_current = nullptr;
 unsigned status::s_current_type = 0;
 unsigned status_bar::s_count = 0;
 
-status_line::status_line(const wchar_t *message, const wchar_t *context) :
+status_line::status_line(const wchar_t *message, const wchar_t *context, bool fails_clean) :
+	status(fails_clean),
 	m_level(level_ok),
 	m_depth(0),
 	m_outer(nullptr)
@@ -148,6 +149,7 @@ status_line::do_fail(const wchar_t *message, uefi::status status)
 
 
 status_bar::status_bar(kernel::args::framebuffer const &fb) :
+	status(fb.size),
 	m_outer(nullptr)
 {
 	m_size = (fb.vertical / num_boxes) - 1;

src/boot/status.h

@@ -17,6 +17,8 @@ namespace boot {
 class status
 {
 public:
+	status(bool fails_clean = true) : m_fails_clean(fails_clean) {}
+
 	virtual void do_warn(const wchar_t *message, uefi::status status) = 0;
 	virtual void do_fail(const wchar_t *message, uefi::status status) = 0;
 
@@ -28,7 +30,7 @@ public:
 	inline static bool warn(const wchar_t *message, uefi::status status = uefi::status::success) {
 		if (!s_current) return false;
 		s_current->do_warn(message, status);
-		return true;
+		return s_current->m_fails_clean;
 	}
 
 	/// Set the state to error, and print a message. If the state is already at
@@ -39,12 +41,15 @@ public:
 	inline static bool fail(const wchar_t *message, uefi::status status) {
 		if (!s_current) return false;
 		s_current->do_fail(message, status);
-		return true;
+		return s_current->m_fails_clean;
 	}
 
 protected:
 	static status *s_current;
 	static unsigned s_current_type;
+
+private:
+	bool m_fails_clean;
 };
 
 /// Scoped status line reporter. Prints a message and an "OK" if no errors
@@ -59,7 +64,11 @@ public:
 	/// Constructor.
 	/// \arg message  Description of the operation in progress
 	/// \arg context  If non-null, printed after `message` and a colon
-	status_line(const wchar_t *message, const wchar_t *context = nullptr);
+	/// \arg fails_clean If true, this object can handle printing failure
+	status_line(
+		const wchar_t *message,
+		const wchar_t *context = nullptr,
+		bool fails_clean = true);
 	~status_line();
 
 	virtual void do_warn(const wchar_t *message, uefi::status status) override;