Add boot archive base and size and map the boot archive.

An archive (ramfs) to be loaded can be specified in the raspberry pi
config.txt with a certain base address. We can use this to put our
floppy boot archive into memory on startup.

During the start procedure we now map that archive so we can later
load the kernel from it.

build/jam/board/raspberry_pi/BoardSetup

@@ -9,6 +9,11 @@ HAIKU_BOOT_PLATFORM = raspberrypi_arm ;
 
 HAIKU_BOARD_LOADER_BASE = 0x0 ;
 
+HAIKU_BOARD_BOOT_ARCHIVE_BASE = 0x04000000 ;
+HAIKU_BOARD_BOOT_ARCHIVE_SIZE = 0x00400000 ;
+	# TODO: needs to be configured in the config.txt
+	#	ramfsfile=haiku-floppyboot.tgz and ramfsaddr=x
+
 #
 # Flash image
 #

src/system/boot/platform/raspberrypi_arm/Jamfile

@@ -12,7 +12,9 @@ UsePrivateHeaders [ FDirName storage ] ;
 UsePrivateHeaders [ FDirName kernel arch $(TARGET_KERNEL_ARCH) board $(TARGET_BOOT_BOARD) ] ;
 
 {
-	local defines = _BOOT_MODE ;
+	local defines = _BOOT_MODE
+		BOOT_ARCHIVE_BASE=$(HAIKU_BOARD_BOOT_ARCHIVE_BASE)
+		BOOT_ARCHIVE_SIZE=$(HAIKU_BOARD_BOOT_ARCHIVE_SIZE) ;
 
 	defines = [ FDefines $(defines) ] ;
 	SubDirCcFlags $(defines) ;

src/system/boot/platform/raspberrypi_arm/start.cpp

@@ -120,6 +120,11 @@ _start(void)
 	mmu_init();
 
 	platform_init_video();
+	// Map in the boot archive loaded into memory by the firmware.
+	args.platform.boot_tgz_size = BOOT_ARCHIVE_SIZE;
+	args.platform.boot_tgz_data = (void*)mmu_map_physical_memory(
+		BOOT_ARCHIVE_BASE, args.platform.boot_tgz_size, kDefaultPageFlags);
+
 	serial_init();
 	console_init();