Support booting with a packaged boot loader

* Add new package haiku_loader.hpkg and move haiku_loader there. The
  package is built without compression, so that the stage 1 boot loader
  has a chance of loading it.
* Adjust the stage 1 boot loader to load the haiku_loader package and
  relocate the boot loader code accordingly.

build/jam/HaikuImage

@@ -197,10 +197,11 @@ SYSTEM_ADD_ONS_FILE_SYSTEMS = bfs bindfs btrfs cdda exfat ext2 fat iso9660 nfs
 	googlefs ;
 
 
-# build the haiku system package and add it
+# build the haiku system packages and add them
 include [ FDirName $(HAIKU_BUILD_RULES_DIR) HaikuPackages ] ;
 
 AddPackageFilesToHaikuImage system : haiku.hpkg ;
+AddPackageFilesToHaikuImage system : haiku_loader.hpkg ;
 
 
 AddSymlinkToHaikuImage . : /boot/common/apps ;
@@ -315,9 +316,6 @@ SEARCH on <post-install>fresh_install
 	= [ FDirName $(HAIKU_TOP) data common settings ] ;
 AddFilesToHaikuImage common settings : <post-install>fresh_install ;
 
-# boot loader
-AddFilesToHaikuImage system : haiku_loader ;
-
 # decorators
 AddDirectoryToHaikuImage home config non-packaged add-ons decorators ;
 #AddFilesToHaikuImage home config add-ons decorators : ;

build/jam/HaikuPackages

@@ -4,6 +4,7 @@ local packages =
 	Haiku
 	HaikuCrossDevel
 	HaikuDevel
+	HaikuLoader
 	HaikuUserguide
 	HaikuWelcome
 	MakefileEngine

build/jam/packages/Haiku

@@ -280,9 +280,6 @@ SEARCH on $(thinkPadFiles) = $(thinkpadDir) ;
 AddFilesToPackage data KeyboardLayouts ThinkPad
 	: $(thinkPadFiles) ;
 
-# boot loader
-AddFilesToPackage : haiku_loader ;
-
 # boot module links
 AddBootModuleSymlinksToPackage
 	acpi@x86 ata@ata pci isa@x86 config_manager dpc

build/jam/packages/HaikuLoader

@@ -0,0 +1,13 @@
+local haikuLoaderPackage = haiku_loader.hpkg ;
+HaikuPackage $(haikuLoaderPackage) ;
+
+
+# boot loader
+AddFilesToPackage : haiku_loader ;
+
+
+# Force no compression, so the stage one loader can directly execute the boot
+# loader.
+HAIKU_PACKAGE_COMPRESSION_LEVEL on $(haikuLoaderPackage) = 0 ;
+
+BuildHaikuPackage $(haikuLoaderPackage) : haiku_loader ;

src/data/package_infos/haiku_loader

@@ -0,0 +1,18 @@
+name			haiku_loader
+version			R1~alpha4_pm-1
+architecture	x86_gcc2
+summary			"The Haiku boot loader"
+description		"The Haiku boot loader."
+
+packager		"The Haiku build system"
+vendor			"Haiku Project"
+
+copyrights		"2001-2013 Haiku, Inc. et al"
+licenses		"MIT"
+
+provides {
+	haiku_loader=R1~alpha4_pm-1
+}
+
+requires {
+}

src/system/boot/platform/bios_ia32/stage1.S

@@ -1,11 +1,11 @@
-; Copyright 2005, Ingo Weinhold, [email protected].
+; Copyright 2005-2013, Ingo Weinhold, [email protected].
 ; Distributed under the terms of the MIT License.
 ;
 ; Stage 1 boot code for the good (?) old BIOS for use as boot block of HD
 ; partitions. The offset of the partition in 512 byte blocks must be written at
 ; position PARTITION_OFFSET_OFFSET (32 bit little endian; makebootable does
 ; that) or otherwise the code can't find the partition.
-; The partition must be a BFS formatted. The file "system/haiku_loader"
+; The partition must be BFS formatted. The file "system/haiku_loader"
 ; (the stage 2 boot loader) loaded into memory at 0x1000:0x0000 (linear address
 ; 0x10000) and entered at 0x:1000:0x0200 with parameters eax - partition offset
 ; in 512 byte blocks and dl - BIOS ID of the boot drive.
@@ -193,6 +193,12 @@ struc	BPlusTreeNode
 	.all_key_length		resw	1
 endstruc
 
+; The beginning of a HPKG header
+struc	HPKGHeader
+	.magic				resd	1
+	.header_size		resw	1
+	; ...
+
 ; That's what esp points to after a "pushad".
 struc	PushadStack
 	.edi						resd	1
@@ -631,7 +637,7 @@ kReadErrorString			db	"read error", 0
 kBadSuperBlockMagicString	db	"bad superblock", 0
 kNotADirectoryString		db	"not a directory", 0
 kBadInodeMagicString		db	"bad inode", 0
-kNoZbeosString				db	"haiku_loader not found", 0
+kNoZbeosString				db	"no loader", 0
 %else
 kErrorString				db	"Failed to load OS. Press any key to reboot..."
 							db	0
@@ -640,7 +646,8 @@ kErrorString				db	"Failed to load OS. Press any key to reboot..."
 ; the path to the boot loader
 kPathComponents:
 pathComponent				"system"
-pathComponent				"haiku_loader"
+pathComponent				"packages"
+pathComponent				"haiku_loader.hpkg"
 							db	0
 
 
@@ -706,20 +713,65 @@ readBootLoader:
 	and			ax, ax
 	jnz			.read_loop
 
-	; We have successfully read the complete boot loader. Set up the
+	; We have successfully read the complete boot loader package. The actual
+	; code is located at the beginning of the package file heap which starts
+	; directly after the header. Since the boot loader code expects to be
+	; located at a fixed address, we have to move it there.
+
+	; First set up the source and target segment registers. We keep the current
+	; value also in bx, since it is easier to do arithmetics with it. We keep
+	; the increment value for the segment registers in dx.
+	mov			bx, 0x1000		; initial ds and es value
+	push		bx
+	pop			ds
+	push		bx
+	pop			es
+	mov			dx, bx			; the increment value for the segment registers
+
+	; Determine how much we have to copy and from where to where. si will be
+	; the source and di the destination pointer (both segment relative) and
+	; ecx is our byte count. To save instructions we only approximate the count.
+	; It may be almost a full segment greater than necessary. But that doesn't
+	; really harm.
+	mov			ecx, edi
+	shr			ecx, 12								; byte count
+	xor			di, di								; target
+	mov			ax, [di + HPKGHeader.header_size]	; header size (big endian)
+	xchg		ah, al
+	mov			si, ax								; source
+
+.move_loop:
+	movsb
+	test		si, si
+	jnz			.move_no_source_overflow
+	add			bx, dx
+	push		bx
+	pop			ds
+.move_no_source_overflow:
+	test		di, di
+	jnz			.move_no_destination_overflow
+	push		bx
+	pop			es
+				; Using bx (the value of ds) is fine, since we assume that the
+				; source is less than a segment ahead of the destination.
+.move_no_destination_overflow:
+	dec			ecx
+	jnz			.move_loop
+
+	; We have successfully prepared the boot loader code. Set up the
 	; environment for it.
 	; eax - partition offset in sectors
+	push		cs
+	pop			ds
+				; temporarily reset ds, so we can access our variables
 	mov dword	eax, [kPartitionOffset]
 
 	; dl - BIOS drive ID
 	xor			edx, edx
 	mov			dl, [bios_drive_id]
 
-	; ds, es
+	; Note: We don't have to set ds and es, since the stage 2 sets them
-	push 		0x07c0
+	; anyway before accessing any data.
-	pop			ds
-	push 		0x1000
-	pop			es
 
 	; enter the boot loader
 	jmp			0x1000:0x200
@@ -949,6 +1001,7 @@ bfsBlockToDiskBlock:
 	ret
 
 
+%if 0
 ; _writeInt32
 ; Writes the given number in 8 digit hexadecimal representation to screen.
 ; Used for debugging only.
@@ -988,6 +1041,7 @@ _writeInt32:
 
 	popad
 	ret
+%endif
 
 
 ; check whether we are small enough