Compressed ROM images now work.

src/arch/i386/prefix/libprefix.S

@@ -37,6 +37,9 @@
  */
 #define HIGHMEM_LOADPOINT ( 4 << 20 )
 
+/* Image compression enabled */
+#define COMPRESS 1
+
 #define CR0_PE 1
 
 	.arch i386
@@ -81,7 +84,11 @@ install_block:
 	
 	/* Do the copy */
 	cld
-	rep addr32 movsb /* or "call decompress16" */
+#if COMPRESS
+	call	decompress16
+#else
+	call	nodecompress16
+#endif
 
 	/* Zero remaining space */
 	movl	%eax, %edi

src/arch/i386/prefix/nonrv2b.S

@@ -0,0 +1,18 @@
+/* Placeholder for decompress16 in non-compressed images */
+
+	.text
+	.arch i386
+	.section ".prefix.lib", "ax", @progbits
+
+	.code16
+	.globl	nodecompress16
+nodecompress16:
+	rep addr32 movsb
+	ret
+
+	/* File split information for the compressor */
+	.section ".zinfo", "a"
+	.ascii	"COPY"
+	.long	_prefix_load_offset
+	.long	_load_size
+	.long	_max_align

src/arch/i386/prefix/romprefix.S

@@ -14,7 +14,7 @@
 	.org	0x00
 romheader:
 	.word	0xAA55			/* BIOS extension signature */
-	.byte	_rom_size		/* Size in 512-byte blocks */
+romheader_size:	.byte	_rom_size	/* Size in 512-byte blocks */
 	jmp	init_vector		/* Initialisation vector */
 	.org	0x16
 	.word	undiheader
@@ -34,7 +34,7 @@ pciheader:
 	.byte	0x02			/* Device Base Type code */
 	.byte	0x00			/* Device Sub-Type code */
 	.byte	0x00			/* Device Interface Type code */
-	.word	_rom_size		/* Image length same as offset 02h */
+pciheader_size:	.word	_rom_size	/* Image length same as offset 02h */
 	.word	0x0001			/* revision level of code/data */
 	.byte	0x00			/* code type */
 	.byte	0x80			/* Flags (last PCI data structure) */
@@ -215,3 +215,15 @@ print_message:
 	popw	%ax
 	ret
 	.size print_message, . - print_message
+
+
+	/* Data update information for the compressor */
+	.section ".zinfo.fixup", "a"
+	.ascii	"SUBB"
+	.long	romheader_size
+	.long	512
+	.long	0
+	.ascii	"SUBW"
+	.long	pciheader_size
+	.long	512
+	.long	0

src/arch/i386/prefix/unnrv2b.S

@@ -35,7 +35,7 @@
 
 	.text
 	.arch i386
-	.section ".prefix", "ax", @progbits
+	.section ".prefix.lib", "ax", @progbits
 
 #ifdef CODE16
 /****************************************************************************
@@ -54,6 +54,7 @@
  * NOTE: It would be possible to build a smaller version of the
  * decompression code for -DKEEP_IT_REAL by using
  *    #define REG(x) x
+ *    #define MOVSB movsb
  * to use 16-bit registers where possible.  This would impose limits
  * that the compressed data size must be in the range [1,65533-%si]
  * and the uncompressed data size must be in the range [1,65536-%di]
@@ -66,6 +67,7 @@
  */
 
 #define REG(x) e ## x
+#define MOVSB addr32 movsb
 
 	.code16
 	.globl	decompress16
@@ -109,11 +111,10 @@ decompress:
 	cld
 	xor	%xBP, %xBP
 	dec	%xBP		/* last_m_off = -1 */
-	add	$4, %xSI	/* Skip "file length" field */
 	jmp	dcl1_n2b
 	
 decompr_literals_n2b:
-	movsb
+	MOVSB
 decompr_loop_n2b:
 	addl	%ebx, %ebx
 	jnz	dcl2_n2b
@@ -157,7 +158,7 @@ decompr_got_mlen_n2b:
 	push	%xSI
 	lea	(%xBP,%xDI), %xSI	/* m_pos = dst + olen + -m_off  */
 	rep
-	es movsb		/* dst[olen++] = *m_pos++ while(m_len > 0) */
+	es MOVSB		/* dst[olen++] = *m_pos++ while(m_len > 0) */
 	pop	%xSI
 	jmp	decompr_loop_n2b
 
@@ -179,3 +180,23 @@ decompr_end_n2b:
 	popl	%ebx
 	pop	%xAX
 	ret
+
+
+	/* File split information for the compressor */
+	.section ".zinfo", "a"
+	.ascii	"COPY"
+	.long	_prefix_load_offset
+	.long	_prefix_progbits_size
+	.long	_max_align
+	.ascii	"PACK"
+	.long	_text16_load_offset
+	.long	_text16_progbits_size
+	.long	_max_align
+	.ascii	"PACK"
+	.long	_data16_load_offset
+	.long	_data16_progbits_size
+	.long	_max_align
+	.ascii	"PACK"
+	.long	_textdata_load_offset
+	.long	_textdata_progbits_size
+	.long	_max_align

src/arch/i386/scripts/i386.lds

@@ -164,6 +164,24 @@ SECTIONS {
 
     _end = .;
 
+    /*
+     * Compressor information block
+     */
+
+    _zinfo_link_addr = 0;
+    . = _zinfo_link_addr;
+    _zinfo = .;
+
+    .zinfo : AT ( _zinfo_load_offset + __zinfo ) {
+	__zinfo = .;
+	_entry = .;
+	*(.zinfo)
+	*(.zinfo.*)
+	_ezinfo_progbits = .;
+    }
+    
+    _ezinfo = .;
+
     /*
      * Dispose of the comment and note sections to make the link map
      * easier to read
@@ -215,6 +233,13 @@ SECTIONS {
 
     _load_size		    = . - _load_addr;
 
+    .			   -= _zinfo_link_addr;
+    _zinfo_load_offset	    = ALIGN ( _max_align );
+    _zinfo_load_addr	    = _zinfo_link_addr + _zinfo_load_offset;
+    _zinfo_size		    = _ezinfo - _zinfo;
+    _zinfo_progbits_size    = _ezinfo_progbits - _zinfo;
+    .			    = _zinfo_load_addr + _zinfo_progbits_size;
+
     _payload_offset	    = _text16_load_offset;
 
     /*