[PATCH 6/18] define asm constant for absolute memory access

[PATCH 6/18] define asm constant for absolute memory access

[Vladimir 'phcoder' Serbinenko]

[-- Attachment #1: Type: text/plain, Size: 121 bytes --]

To access an absolute address you need to do it through a label on Apple's cc

-- 
Regards
Vladimir 'phcoder' Serbinenko

[-- Attachment #2: 06_abs.diff --]
[-- Type: text/x-patch, Size: 11490 bytes --]

diff --git a/boot/i386/pc/boot.S b/boot/i386/pc/boot.S
index fc31f5a..c22dccd 100644
--- a/boot/i386/pc/boot.S
+++ b/boot/i386/pc/boot.S
@@ -30,7 +30,11 @@
 #define ABS(x) (x-_start+0x7c00)
 
 	/* Print message string */
+#ifdef APPLE_CC
+#define MSG(x)	x ## _abs = ABS(x); movw $x ## _abs, %si; call message
+#else
 #define MSG(x)	movw $ABS(x), %si; call message
+#endif
 
 	.file	"boot.S"
 
@@ -125,7 +129,12 @@ boot_drive_check:
 	 * ljmp to the next instruction because some bogus BIOSes
 	 * jump to 07C0:0000 instead of 0000:7C00.
 	 */
+#ifdef APPLE_CC
+	real_start_abs = ABS(real_start)
+	ljmp	$0, $(real_start_abs)
+#else
 	ljmp	$0, $ABS(real_start)
+#endif
 
 real_start:	
 
@@ -143,7 +152,12 @@ real_start:
 	 *  Check if we have a forced disk reference here
 	 */
         /* assign root_drive at the same time */
-        movw    ABS(boot_drive), %ax
+#ifdef APPLE_CC
+	boot_drive_abs = ABS (boot_drive)
+	movw    boot_drive_abs, %ax
+#else
+	movw    ABS(boot_drive), %ax
+#endif
         movb    %ah, %dh
 	cmpb	$0xff, %al
 	je	1f
@@ -156,7 +170,12 @@ real_start:
 	MSG(notification_string)
 
 	/* set %si to the disk address packet */
+#ifdef APPLE_CC
+	disk_address_packet_abs = ABS (disk_address_packet)
+	movw	$disk_address_packet_abs, %si
+#else
 	movw	$ABS(disk_address_packet), %si
+#endif
 	
 	/* do not probe LBA if the drive is a floppy */
 	testb	$GRUB_BOOT_MACHINE_BIOS_HD_FLAG, %dl
@@ -197,10 +216,18 @@ lba_mode:
 	movw	$0x0010, (%si)
 
 	/* the absolute address */
+#ifdef APPLE_CC
+	kernel_sector_abs = ABS (kernel_sector)
+	movl	(kernel_sector_abs), %ebx
+	movl	%ebx, 8(%si)
+	movl	(kernel_sector_abs + 4), %ebx
+	movl	%ebx, 12(%si)
+#else
 	movl	ABS(kernel_sector), %ebx
 	movl	%ebx, 8(%si)
 	movl	ABS(kernel_sector + 4), %ebx
 	movl	%ebx, 12(%si)
+#endif
 
 	/* the segment of buffer address */
 	movw	$GRUB_BOOT_MACHINE_BUFFER_SEG, 6(%si)
@@ -267,12 +294,22 @@ final_init:
 
 setup_sectors:
 	/* load logical sector start (top half) */
+#ifdef APPLE_CC
+	kernel_sector_abs = ABS (kernel_sector)
+	movl	(kernel_sector_abs + 4), %eax
+#else
 	movl	ABS(kernel_sector + 4), %eax
+#endif
+
 	orl	%eax, %eax
 	jnz	geometry_error
 	
 	/* load logical sector start (bottom half) */
+#ifdef APPLE_CC
+	movl	(kernel_sector_abs), %eax
+#else
 	movl	ABS(kernel_sector), %eax
+#endif
 
 	/* zero %edx */
 	xorl	%edx, %edx
@@ -336,7 +373,12 @@ setup_sectors:
 	movw	%es, %bx
 	
 copy_buffer:
+#ifdef APPLE_CC
+	kernel_segment_abs = ABS (kernel_segment)
+	movw	(kernel_segment_abs), %es
+#else
 	movw	ABS(kernel_segment), %es
+#endif
 
 	/*
 	 * We need to save %cx and %si because the startup code in
@@ -360,7 +402,12 @@ copy_buffer:
         popw    %dx
 
 	/* boot kernel */
+#ifdef APPLE_CC
+	kernel_address_abs = ABS (kernel_address)
+	jmp	*(kernel_address_abs)
+#else
 	jmp	*(kernel_address)
+#endif
 
 /* END OF MAIN LOOP */
 
@@ -446,7 +493,12 @@ floppy_probe:
  *  Perform floppy probe.
  */
 
+#ifdef APPLE_CC
+	probe_values_abs = ABS (probe_values)
+	movw	$(probe_values_abs-1), %si
+#else
 	movw	$ABS(probe_values-1), %si
+#endif
 
 probe_loop:
 	/* reset floppy controller INT 13h AH=0 */
diff --git a/boot/i386/pc/cdboot.S b/boot/i386/pc/cdboot.S
index 133f8de..b32f82c 100644
--- a/boot/i386/pc/cdboot.S
+++ b/boot/i386/pc/cdboot.S
@@ -67,8 +67,15 @@ bi_reserved:
 	movw	%ax, %ds
 	movw	%ax, %es
 
+#ifdef APPLE_CC
+	err_noboot_msg_abs = 0x7C00 + err_noboot_msg - start
+	movw	$err_noboot_msg_abs, %si
+	bi_length_dif = bi_length - next
+	movl	%cs:bi_length_dif(%bx), %ecx
+#else
 	movw	$(0x7C00 + err_noboot_msg - start), %si
 	movl	%cs: bi_length - next(%bx), %ecx
+#endif
 	orl	%ecx, %ecx
 	jz	fail
 
@@ -152,7 +159,12 @@ read_cdrom:
 	ret
 
 cdrom_fail:
+#ifdef APPLE_CC
+	err_cdfail_msg_abs = 0x7C00 + err_cdfail_msg - start
+	movw	$(err_cdfail_msg_abs), %si
+#else
 	movw	$(0x7C00 + err_cdfail_msg - start), %si
+#endif
 
 fail:
 	movb	$0x0e, %ah
diff --git a/boot/i386/pc/diskboot.S b/boot/i386/pc/diskboot.S
index 0c8e75d..f29ddaa 100644
--- a/boot/i386/pc/diskboot.S
+++ b/boot/i386/pc/diskboot.S
@@ -28,7 +28,11 @@
 #define ABS(x) (x-_start+GRUB_BOOT_MACHINE_KERNEL_ADDR)
 	
 	/* Print message string */
+#ifdef APPLE_CC
+#define MSG(x)	x ## _abs = ABS(x); mov $x ## _abs, %esi; call message
+#else
 #define MSG(x)	movw $ABS(x), %si; call message
+#endif
 
 	.file	"diskboot.S"
 
@@ -61,7 +65,12 @@ _start:
 	popw	%si
 	
 	/* this sets up for the first run through "bootloop" */
+#ifdef APPLE_CC
+	firstlist_off_abs = ABS (firstlist - GRUB_BOOT_MACHINE_LIST_SIZE)
+	movl	$firstlist_off_abs, %edi
+#else
 	movw	$ABS(firstlist - GRUB_BOOT_MACHINE_LIST_SIZE), %di
+#endif
 
 	/* save the sector number of the second sector in %ebp */
 	movl	(%di), %ebp
diff --git a/boot/i386/pc/lnxboot.S b/boot/i386/pc/lnxboot.S
index e7f55df..0db6826 100644
--- a/boot/i386/pc/lnxboot.S
+++ b/boot/i386/pc/lnxboot.S
@@ -123,8 +123,15 @@ data_leng:
 
 linux_init:
 
+#ifdef APPLE_CC
+	reg_edx_rel = reg_edx - start 
+	code32_start_rel = code32_start - start 
+	movw	%cs:(reg_edx_rel), %dx
+	movl	%cs:(code32_start_rel), %ebp
+#else
 	movw	%cs:(reg_edx - start), %dx
 	movl	%cs:(code32_start - start), %ebp
+#endif
 
 linux_next:
 
@@ -132,12 +139,22 @@ linux_next:
 
 normalize:
 	popw	%bx
+#ifdef APPLE_CC
+	normalize_rel = normalize - start
+	subw	$(normalize_rel), %bx
+#else
 	subw	$(normalize - start), %bx
+#endif
 	shrw	$4, %bx
 	movw	%cs, %ax
 	addw	%bx, %ax
 	pushw	%ax
+#ifdef APPLE_CC
+	real_code_rel = real_code - start
+	pushw	$(real_code_rel)
+#else
 	pushw	$(real_code - start)
+#endif
 	lret				/* Jump to real_code.  */
 
 real_code:
@@ -164,7 +181,12 @@ real_code:
 	rep
 	movsl
 
+#ifdef APPLE_CC
+	real_code_2_rel = real_code_2 - start
+	ljmp	$(CODE_ADDR >> 4), $(real_code_2_rel)
+#else
 	ljmp	$(CODE_ADDR >> 4), $(real_code_2  - start)
+#endif
 
 real_code_2:
 
@@ -189,8 +211,15 @@ real_code_2:
 	cmpl	$MULTIBOOT_MAGIC, %ss:(DATA_ADDR + GRUB_KERNEL_MACHINE_DATA_END)
 	jz	1f
 
+#ifdef APPLE_CC
+	ramdisk_image_rel = ramdisk_image - start
+	ramdisk_size_rel = ramdisk_size - start
+	movl	(ramdisk_image_rel), %esi
+	movl	(ramdisk_size_rel), %ecx
+#else
 	movl	(ramdisk_image - start), %esi
 	movl	(ramdisk_size - start), %ecx
+#endif
 	movl	$(DATA_ADDR - 0x200), %edi
 	jmp	2f
 
@@ -205,7 +234,12 @@ real_code_2:
 	movsbl	%dh, %eax
 	movl	%eax, %ss:(DATA_ADDR + GRUB_KERNEL_MACHINE_INSTALL_DOS_PART)
 
+#ifdef APPLE_CC
+	reg_edx_rel = reg_edx - start
+	movsbl	(reg_edx_rel + 2), %eax
+#else
 	movsbl	(reg_edx + 2 - start), %eax
+#endif
 	movl	%eax, %ss:(DATA_ADDR + GRUB_KERNEL_MACHINE_INSTALL_BSD_PART)
 
 	movb	$0xFF, %dh
@@ -234,6 +268,28 @@ move_memory:
 	pushl	%ecx
 
 	movl	%esi, %eax
+#ifdef APPLE_CC
+	gdt_src1_rel = gdt_src1 - start
+	gdt_src2_rel = gdt_src2 - start
+	gdt_dst1_rel = gdt_dst1 - start
+	gdt_dst2_rel = gdt_dst2 - start
+	gdt_rel = gdt - start
+
+	movw	%si, (gdt_src1_rel)
+	shrl	$16, %eax
+	movb	%al, (gdt_src1_rel + 2)
+	movb	%ah, (gdt_src2_rel)
+
+	movl	%edi, %eax
+	movw	%di, (gdt_dst1_rel)
+	shrl	$16, %eax
+	movb	%al, (gdt_dst1_rel + 2)
+	movb	%ah, (gdt_dst2_rel)
+
+	movw	$(gdt_rel), %si
+	movb	$0x87, %ah
+	shrw	$1, %cx
+#else
 	movw	%si, (gdt_src1 - start)
 	shrl	$16, %eax
 	movb	%al, (gdt_src1 + 2 - start)
@@ -248,6 +304,7 @@ move_memory:
 	movw	$(gdt - start), %si
 	movb	$0x87, %ah
 	shrw	$1, %cx
+#endif
 
 	int	$0x15
 
@@ -257,7 +314,12 @@ move_memory:
 	popl	%esi
 
 	jnc	2f
+#ifdef APPLE_CC
+	err_int15_msg_rel = err_int15_msg - start
+	movw	$(err_int15_msg_rel), %si
+#else
 	movw	$(err_int15_msg - start), %si
+#endif
 	jmp	fail
 
 2:
diff --git a/commands/i386/pc/drivemap_int13h.S b/commands/i386/pc/drivemap_int13h.S
index 23b7302..7a3e8e7 100644
--- a/commands/i386/pc/drivemap_int13h.S
+++ b/commands/i386/pc/drivemap_int13h.S
@@ -30,7 +30,12 @@ FUNCTION(grub_drivemap_handler)
 	/* Map the drive number (always in DL).  */
 	push	%ax
 	push	%bx
+#ifdef APPLE_CC
+	grub_drivemap_mapstart_ofs = INT13H_OFFSET(EXT_C(grub_drivemap_mapstart))
+	movw	$grub_drivemap_mapstart_ofs, %bx
+#else
 	movw	$INT13H_OFFSET(EXT_C(grub_drivemap_mapstart)), %bx
+#endif
 
 more_remaining:
 	movw	%cs:(%bx), %ax
diff --git a/kern/i386/pc/startup.S b/kern/i386/pc/startup.S
index fc83c4c..23f84ed 100644
--- a/kern/i386/pc/startup.S
+++ b/kern/i386/pc/startup.S
@@ -69,7 +69,12 @@ _start:
 	/*
 	 *  Guarantee that "main" is loaded at 0x0:0x8200.
 	 */
+#ifdef APPLE_CC
+	codestart_abs = ABS(codestart) - 0x10000
+	ljmp $0, $(codestart_abs)
+#else
 	ljmp $0, $ABS(codestart)
+#endif
 
 	/*
 	 *  Compatibility version number
@@ -249,12 +254,24 @@ codestart:
 	movsb
 #endif
 	
+#ifdef APPLE_CC
+	/* clean out the bss */
+	bss_start_abs = ABS (bss_start)
+	bss_end_abs = ABS (bss_end)
+
+	movl    bss_start_abs, %edi
+
+	/* compute the bss length */
+	movl	bss_end_abs, %ecx
+	subl	%edi, %ecx
+#else
 	/* clean out the bss */
 	movl	$BSS_START_SYMBOL, %edi
 
 	/* compute the bss length */
 	movl	$END_SYMBOL, %ecx
 	subl	%edi, %ecx
+#endif
 			
 	/* clean out */
 	xorl	%eax, %eax
@@ -293,7 +310,13 @@ real_to_prot:
 	cli
 
 	/* load the GDT register */
+#ifdef APPLE_CC
+	mov %cs, %ax
+	mov %ax, %ds
+	DATA32	ADDR32	lgdt	gdtdesc
+#else
 	DATA32	ADDR32	lgdt	%cs:gdtdesc
+#endif
 
 	/* turn on protected mode */
 	movl	%cr0, %eax
@@ -1223,7 +1246,12 @@ translate_keycode:
 	pushw	%bx
 	pushw	%si
 	
+#ifdef APPLE_CC
+	translation_table_abs = ABS (translation_table) - 0x10000
+	movw	$(translation_table_abs), %si
+#else
 	movw	$ABS(translation_table), %si
+#endif
 	
 1:	lodsw
 	/* check if this is the end */
diff --git a/mmap/i386/pc/mmap_helper.S b/mmap/i386/pc/mmap_helper.S
index ab7c0d2..f153f1c 100644
--- a/mmap/i386/pc/mmap_helper.S
+++ b/mmap/i386/pc/mmap_helper.S
@@ -28,7 +28,12 @@ VARIABLE(grub_machine_mmaphook_int12)
 	push %ds
 	push %cs
 	pop %ds
+#ifdef APPLE_CC
+	grub_machine_mmaphook_kblow_rel = DS (EXT_C (grub_machine_mmaphook_kblow))
+	movw (grub_machine_mmaphook_kblow_rel), %ax
+#else
 	movw DS (EXT_C (grub_machine_mmaphook_kblow)), %ax
+#endif
 	pop %ds
 	iret
 
@@ -53,8 +58,15 @@ e801:
 	push %ds
 	push %cs
 	pop %ds
+#ifdef APPLE_CC
+	grub_machine_mmaphook_kbin16mb_rel = DS (EXT_C (grub_machine_mmaphook_kbin16mb))
+	grub_machine_mmaphook_64kbin4gb_rel = DS (EXT_C (grub_machine_mmaphook_64kbin4gb))
+	movw (grub_machine_mmaphook_kbin16mb_rel), %ax
+	movw (grub_machine_mmaphook_64kbin4gb_rel), %bx
+#else
 	movw DS (EXT_C (grub_machine_mmaphook_kbin16mb)), %ax
 	movw DS (EXT_C (grub_machine_mmaphook_64kbin4gb)), %bx
+#endif
 	movw %ax, %cx
 	movw %bx, %dx
 	pop %ds
@@ -66,26 +78,42 @@ h88:
 	push %ds
 	push %cs
 	pop %ds
+#ifdef APPLE_CC
+	movw (grub_machine_mmaphook_kbin16mb_rel), %ax
+#else
 	movw DS (EXT_C (grub_machine_mmaphook_kbin16mb)), %ax
+#endif
 	pop %ds
 	clc
 	iret
 
 e820:
+#ifdef APPLE_CC
+	mmaphook_mmap_rel = DS(mmaphook_mmap)
+	mmaphook_mmap_num_rel = DS(EXT_C(grub_machine_mmaphook_mmap_num))
+#endif
 	popf
 	push %ds
 	push %cs
 	pop %ds
 	cmpw $20, %cx
 	jb errexit
+#ifdef APPLE_CC
+	cmpw (mmaphook_mmap_num_rel), %bx
+#else
 	cmpw DS (EXT_C (grub_machine_mmaphook_mmap_num)), %bx
+#endif
 	jae errexit
 	cmp $0x534d4150, %edx
 	jne errexit
 	push %si
 	push %di
 	movw $20, %cx
+#ifdef APPLE_CC
+	movl $(mmaphook_mmap_rel), %esi
+#else
 	movw $(DS(mmaphook_mmap)), %si
+#endif
 	mov %bx, %ax
 	imul $20, %ax
 	add %ax, %si
@@ -94,7 +122,11 @@ e820:
 	pop %si
 	movl $20, %ecx
 	inc %bx
+#ifdef APPLE_CC
+	cmpw (mmaphook_mmap_num_rel), %bx
+#else
 	cmpw DS(EXT_C(grub_machine_mmaphook_mmap_num)), %bx
+#endif
 	jb noclean
 	xor %bx, %bx	
 noclean:	

Re: [PATCH 6/18] define asm constant for absolute memory access

[Pavel Roskin]

On Sat, 2009-05-30 at 16:46 +0200, Vladimir 'phcoder' Serbinenko wrote:
> +#ifdef APPLE_CC
> +#define MSG(x) x ## _abs = ABS(x); movw $x ## _abs, %si; call message
> +#else
>  #define MSG(x) movw $ABS(x), %si; call message
> +#endif

I have verified that defining APPLE_CC on Fedora would produce exactly
the same bytecode.  I don't see any reason to have preprocessor
conditionals all over the place.  Are you trying to support as without
variables?

> +#ifdef APPLE_CC
> +       movl $(mmaphook_mmap_rel), %esi
> +#else
>         movw $(DS(mmaphook_mmap)), %si
> +#endif

That's not an equivalent replacement.  The argument width is different.

-- 
Regards,
Pavel Roskin

Re: [PATCH 6/18] define asm constant for absolute memory access

[Vladimir 'phcoder' Serbinenko]

[-- Attachment #1: Type: text/plain, Size: 1408 bytes --]

On Tue, Jun 16, 2009 at 3:28 AM, Pavel Roskin <proski@gnu.org> wrote:

> On Sat, 2009-05-30 at 16:46 +0200, Vladimir 'phcoder' Serbinenko wrote:
> > +#ifdef APPLE_CC
> > +#define MSG(x) x ## _abs = ABS(x); movw $x ## _abs, %si; call message
> > +#else
> >  #define MSG(x) movw $ABS(x), %si; call message
> > +#endif
>
> I have verified that defining APPLE_CC on Fedora would produce exactly
> the same bytecode.  I don't see any reason to have preprocessor
> conditionals all over the place.  Are you trying to support as without
> variables?
>
the problem is absolute adressing. Apple's AS issues a relocation directive
for the code of type:
mov a-b, %eax
(probably because of possibility of external aliases)
which is then too complex for linker to resolve, that's why I needed to use
constants as recommended by AS warning

>
> > +#ifdef APPLE_CC
> > +       movl $(mmaphook_mmap_rel), %esi
> > +#else
> >         movw $(DS(mmaphook_mmap)), %si
> > +#endif
>
> That's not an equivalent replacement.  The argument width is different.
>
I know. Sometimes because of the quirks I had to replace some code with a
less logical alternative which should however work in the flow

>
> --
> Regards,
> Pavel Roskin
>
>
> _______________________________________________
> Grub-devel mailing list
> Grub-devel@gnu.org
> http://lists.gnu.org/mailman/listinfo/grub-devel
>



-- 
Regards
Vladimir 'phcoder' Serbinenko

[-- Attachment #2: Type: text/html, Size: 2282 bytes --]

Re: [PATCH 6/18] define asm constant for absolute memory access

[Pavel Roskin]

On Tue, 2009-06-16 at 12:49 +0200, Vladimir 'phcoder' Serbinenko wrote:

>         > +#ifdef APPLE_CC
>         > +       movl $(mmaphook_mmap_rel), %esi
>         > +#else
>         >         movw $(DS(mmaphook_mmap)), %si
>         > +#endif
>         
>         That's not an equivalent replacement.  The argument width is
>         different.
> I know. Sometimes because of the quirks I had to replace some code
> with a less logical alternative which should however work in the flow 

Please don't commit such changes without an explicit permissions form
the maintainers.  It's very time consuming to verify such code after it
has been committed.

-- 
Regards,
Pavel Roskin