1 files changed, 128 insertions, 0 deletions
diff --git a/arch/i386/boot/compressed/head.S b/arch/i386/boot/compressed/head.S
new file mode 100644
index 000000000000..c5e80b69e7d4
--- /dev/null
+++ b/arch/i386/boot/compressed/head.S
@@ -0,0 +1,128 @@
+/*
+ *  linux/boot/head.S
+ *
+ *  Copyright (C) 1991, 1992, 1993  Linus Torvalds
+ */
+/*
+ *  head.S contains the 32-bit startup code.
+ *
+ * NOTE!!! Startup happens at absolute address 0x00001000, which is also where
+ * the page directory will exist. The startup code will be overwritten by
+ * the page directory. [According to comments etc elsewhere on a compressed
+ * kernel it will end up at 0x1000 + 1Mb I hope so as I assume this. - AC]
+ *
+ * Page 0 is deliberately kept safe, since System Management Mode code in 
+ * laptops may need to access the BIOS data stored there.  This is also
+ * useful for future device drivers that either access the BIOS via VM86 
+ * mode.
+ */
+/*
+ * High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996
+ */
+.text
+#include <linux/linkage.h>
+#include <asm/segment.h>
+        .globl startup_32
+        
+startup_32:
+        cld
+        cli
+        movl $(__BOOT_DS),%eax
+        movl %eax,%ds
+        movl %eax,%es
+        movl %eax,%fs
+        movl %eax,%gs
+        lss stack_start,%esp
+        xorl %eax,%eax
+1:      incl %eax               # check that A20 really IS enabled
+        movl %eax,0x000000      # loop forever if it isn't
+        cmpl %eax,0x100000
+        je 1b
+/*
+ * Initialize eflags.  Some BIOS's leave bits like NT set.  This would
+ * confuse the debugger if this code is traced.
+ * XXX - best to initialize before switching to protected mode.
+ */
+        pushl $0
+        popfl
+/*
+ * Clear BSS
+ */
+        xorl %eax,%eax
+        movl $_edata,%edi
+        movl $_end,%ecx
+        subl %edi,%ecx
+        cld
+        rep
+        stosb
+/*
+ * Do the decompression, and jump to the new kernel..
+ */
+        subl $16,%esp   # place for structure on the stack
+        movl %esp,%eax
+        pushl %esi      # real mode pointer as second arg
+        pushl %eax      # address of structure as first arg
+        call decompress_kernel
+        orl  %eax,%eax 
+        jnz  3f
+        popl %esi       # discard address
+        popl %esi       # real mode pointer
+        xorl %ebx,%ebx
+        ljmp $(__BOOT_CS), $0x100000
+/*
+ * We come here, if we were loaded high.
+ * We need to move the move-in-place routine down to 0x1000
+ * and then start it with the buffer addresses in registers,
+ * which we got from the stack.
+ */
+3:
+        movl $move_routine_start,%esi
+        movl $0x1000,%edi
+        movl $move_routine_end,%ecx
+        subl %esi,%ecx
+        addl $3,%ecx
+        shrl $2,%ecx
+        cld
+        rep
+        movsl
+        popl %esi       # discard the address
+        popl %ebx       # real mode pointer
+        popl %esi       # low_buffer_start
+        popl %ecx       # lcount
+        popl %edx       # high_buffer_start
+        popl %eax       # hcount
+        movl $0x100000,%edi
+        cli             # make sure we don't get interrupted
+        ljmp $(__BOOT_CS), $0x1000 # and jump to the move routine
+/*
+ * Routine (template) for moving the decompressed kernel in place,
+ * if we were high loaded. This _must_ PIC-code !
+ */
+move_routine_start:
+        movl %ecx,%ebp
+        shrl $2,%ecx
+        rep
+        movsl
+        movl %ebp,%ecx
+        andl $3,%ecx
+        rep
+        movsb
+        movl %edx,%esi
+        movl %eax,%ecx  # NOTE: rep movsb won't move if %ecx == 0
+        addl $3,%ecx
+        shrl $2,%ecx
+        rep
+        movsl
+        movl %ebx,%esi  # Restore setup pointer
+        xorl %ebx,%ebx
+        ljmp $(__BOOT_CS), $0x100000
+move_routine_end:

diff --git a/arch/i386/boot/compressed/head.S b/arch/i386/boot/compressed/head.S new file mode 100644 index 000000000000..c5e80b69e7d4 --- /dev/null +++ b/arch/i386/boot/compressed/head.S
@@ -0,0 +1,128 @@
	1	/*
	2	* linux/boot/head.S
	3	*
	4	* Copyright (C) 1991, 1992, 1993 Linus Torvalds
	5	*/
	6
	7	/*
	8	* head.S contains the 32-bit startup code.
	9	*
	10	* NOTE!!! Startup happens at absolute address 0x00001000, which is also where
	11	* the page directory will exist. The startup code will be overwritten by
	12	* the page directory. [According to comments etc elsewhere on a compressed
	13	* kernel it will end up at 0x1000 + 1Mb I hope so as I assume this. - AC]
	14	*
	15	* Page 0 is deliberately kept safe, since System Management Mode code in
	16	* laptops may need to access the BIOS data stored there. This is also
	17	* useful for future device drivers that either access the BIOS via VM86
	18	* mode.
	19	*/
	20
	21	/*
	22	* High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996
	23	*/
	24	.text
	25
	26	#include <linux/linkage.h>
	27	#include <asm/segment.h>
	28
	29	.globl startup_32
	30
	31	startup_32:
	32	cld
	33	cli
	34	movl $(__BOOT_DS),%eax
	35	movl %eax,%ds
	36	movl %eax,%es
	37	movl %eax,%fs
	38	movl %eax,%gs
	39
	40	lss stack_start,%esp
	41	xorl %eax,%eax
	42	1: incl %eax # check that A20 really IS enabled
	43	movl %eax,0x000000 # loop forever if it isn't
	44	cmpl %eax,0x100000
	45	je 1b
	46
	47	/*
	48	* Initialize eflags. Some BIOS's leave bits like NT set. This would
	49	* confuse the debugger if this code is traced.
	50	* XXX - best to initialize before switching to protected mode.
	51	*/
	52	pushl $0
	53	popfl
	54	/*
	55	* Clear BSS
	56	*/
	57	xorl %eax,%eax
	58	movl $_edata,%edi
	59	movl $_end,%ecx
	60	subl %edi,%ecx
	61	cld
	62	rep
	63	stosb
	64	/*
	65	* Do the decompression, and jump to the new kernel..
	66	*/
	67	subl $16,%esp # place for structure on the stack
	68	movl %esp,%eax
	69	pushl %esi # real mode pointer as second arg
	70	pushl %eax # address of structure as first arg
	71	call decompress_kernel
	72	orl %eax,%eax
	73	jnz 3f
	74	popl %esi # discard address
	75	popl %esi # real mode pointer
	76	xorl %ebx,%ebx
	77	ljmp $(__BOOT_CS), $0x100000
	78
	79	/*
	80	* We come here, if we were loaded high.
	81	* We need to move the move-in-place routine down to 0x1000
	82	* and then start it with the buffer addresses in registers,
	83	* which we got from the stack.
	84	*/
	85	3:
	86	movl $move_routine_start,%esi
	87	movl $0x1000,%edi
	88	movl $move_routine_end,%ecx
	89	subl %esi,%ecx
	90	addl $3,%ecx
	91	shrl $2,%ecx
	92	cld
	93	rep
	94	movsl
	95
	96	popl %esi # discard the address
	97	popl %ebx # real mode pointer
	98	popl %esi # low_buffer_start
	99	popl %ecx # lcount
	100	popl %edx # high_buffer_start
	101	popl %eax # hcount
	102	movl $0x100000,%edi
	103	cli # make sure we don't get interrupted
	104	ljmp $(__BOOT_CS), $0x1000 # and jump to the move routine
	105
	106	/*
	107	* Routine (template) for moving the decompressed kernel in place,
	108	* if we were high loaded. This _must_ PIC-code !
	109	*/
	110	move_routine_start:
	111	movl %ecx,%ebp
	112	shrl $2,%ecx
	113	rep
	114	movsl
	115	movl %ebp,%ecx
	116	andl $3,%ecx
	117	rep
	118	movsb
	119	movl %edx,%esi
	120	movl %eax,%ecx # NOTE: rep movsb won't move if %ecx == 0
	121	addl $3,%ecx
	122	shrl $2,%ecx
	123	rep
	124	movsl
	125	movl %ebx,%esi # Restore setup pointer
	126	xorl %ebx,%ebx
	127	ljmp $(__BOOT_CS), $0x100000
	128	move_routine_end: