nova: export kernel messages via memory

Fixes #2207

repos/base-nova/include/nova/syscall-generic.h

@@ -91,6 +91,7 @@ namespace Nova {
 		struct Mem_desc
 		{
 			enum Type {
+				HYPERVISOR_LOG      = -6,
 				FRAMEBUFFER         = -5,
 				ACPI_XSDT           = -4,
 				ACPI_RSDT           = -3,

repos/base-nova/src/core/platform.cc

@@ -527,6 +527,9 @@ Platform::Platform() :
 		ram_alloc()->add_range(base, size);
 	}
 
+	uint64_t hyp_log = 0;
+	uint64_t hyp_log_size = 0;
+
 	/*
 	 * Exclude all non-available memory from physical allocator AFTER all
 	 * available RAM was added - otherwise the non-available memory gets not
@@ -536,6 +539,14 @@ Platform::Platform() :
 	for (unsigned i = 0; i < num_mem_desc; i++, mem_desc++) {
 		if (mem_desc->type == Hip::Mem_desc::AVAILABLE_MEMORY) continue;
 
+		if (verbose_boot_info)
+			log("detected res memory: ", Hex(mem_desc->addr), " - size: ",
+			    Hex(mem_desc->size), " type=", (int)mem_desc->type);
+		if (mem_desc->type == Hip::Mem_desc::HYPERVISOR_LOG) {
+			hyp_log = mem_desc->addr;
+			hyp_log_size = mem_desc->size;
+		}
+
 		/* skip regions above 4G on 32 bit, no op on 64 bit */
 		if (mem_desc->addr > ~0UL) continue;
 
@@ -711,6 +722,11 @@ Platform::Platform() :
 		init_core_log( Core_log_range { core_local_addr, log_size } );
 	}
 
+	/* export hypervisor log memory */
+	if (hyp_log && hyp_log_size)
+		_rom_fs.insert(new (core_mem_alloc()) Rom_module(hyp_log, hyp_log_size,
+		                                                 "kernel_log"));
+
 	/* I/O port allocator (only meaningful for x86) */
 	_io_port_alloc.add_range(0, 0x10000);
 

repos/os/run/log_core.run

@@ -12,11 +12,15 @@ proc log_service { } {
 	return ram
 }
 
+if {[have_spec nova]} {
+	proc kernel_output { } { return "novga logmem" }
+}
+
 build "core init drivers/timer server/vfs server/fs_log app/log_core"
 
 create_boot_directory
 
-install_config {
+append config {
 <config>
 	<parent-provides>
 		<service name="CPU"/>
@@ -76,9 +80,28 @@ install_config {
 			<service name="CPU"> <parent/> </service>
 			<service name="LOG"> <parent/> </service>
 		</route>
-	</start>
-</config>
-}
+	</start>}
+
+append_if [have_spec nova] config {
+	<start name="log_kernel">
+		<binary name="log_core"/>
+		<resource name="RAM" quantum="10M"/>
+		<config period_ms="2000"/>
+		<route>
+			<service name="ROM" unscoped_label="log_core"> <parent/> </service>
+			<service name="ROM" unscoped_label="ld.lib.so"> <parent/> </service>
+			<service name="ROM" label="log"> <parent label="kernel_log"/> </service>
+			<service name="Timer"> <child name="timer"/> </service>
+			<service name="PD"> <parent/> </service>
+			<service name="CPU"> <parent/> </service>
+			<service name="LOG"> <parent/> </service>
+		</route>
+	</start>}
+
+append config {
+</config>}
+
+install_config $config
 
 build_boot_image "core init timer ld.lib.so vfs fs_log log_core vfs.lib.so"
 

tool/run/boot_dir/nova

@@ -3,10 +3,10 @@ proc binary_name_core_o    { } { return "core-nova.o" }
 proc binary_name_timer     { } { return "nova_timer_drv" }
 
 proc kernel_files { } { return hypervisor }
-
+proc kernel_output { } { return "novga serial" }
 
 proc run_boot_string { } {
-	return "\n\r\fNOVA Microhypervisor"
+	return "\nHypervisor reports "
 }
 
 
@@ -126,7 +126,7 @@ proc run_boot_dir {binaries} {
 		puts $fh " insmod multiboot2"
 		puts $fh " insmod gzio"
 		puts $fh " multiboot2 /boot/bender $serial_bender_opt"
-		puts $fh " module2 /boot/hypervisor hypervisor iommu serial novpid novga"
+		puts $fh " module2 /boot/hypervisor hypervisor iommu novpid [kernel_output]"
 		puts $fh " module2 /boot/image.elf.gz image.elf"
 		puts $fh "}"
 		close $fh
@@ -148,7 +148,7 @@ proc run_boot_dir {binaries} {
 		#
 		set fh [open "[run_dir]/config-52-54-00-12-34-56" "WRONLY CREAT TRUNC"]
 		puts $fh " exec /boot/bender"
-		puts $fh " load /boot/hypervisor iommu serial novpid novga"
+		puts $fh " load /boot/hypervisor iommu novpid [kernel_output]"
 		puts $fh " load /boot/image.elf"
 		close $fh