Self-relocation code for powerpc.

1 files changed, 99 insertions, 1 deletions

diff --git a/lib/csu/powerpc/md_init.h b/lib/csu/powerpc/md_init.h
index 3fab44b9a98..8625ce57cf1 100644
--- a/lib/csu/powerpc/md_init.h
+++ b/lib/csu/powerpc/md_init.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: md_init.h,v 1.2 2013/12/03 06:21:41 guenther Exp $ */
+/* $OpenBSD: md_init.h,v 1.3 2014/12/26 13:52:01 kurt Exp $ */
 
 /*-
  * Copyright (c) 2001 Ross Harvey
@@ -148,3 +148,101 @@ __asm(									\
 "	mr %r6, %r22							\n" \
 "	b ___start							\n" \
 )
+
+#define	MD_RCRT0_START							\
+__asm(									\
+"	.text								\n" \
+"	.section	\".text\"					\n" \
+"	.align 2							\n" \
+"	.globl	_start							\n" \
+"	.type	_start, @function					\n" \
+"	.globl	__start							\n" \
+"	.type	__start, @function					\n" \
+"_start:								\n" \
+"__start:								\n" \
+"	mr	%r19, %r1		# save stack in r19		\n" \
+"	stwu	1, (-16 -((9+3)*4))(%r1) # allocate dl_data		\n" \
+"									\n" \
+"	# move argument registers to saved registers for startup flush	\n" \
+"	mr %r20, %r3			# argc				\n" \
+"	mr %r21, %r4			# argv				\n" \
+"	mr %r22, %r5			# envp				\n" \
+"	mflr	%r27	/* save off old link register */		\n" \
+"	stw	%r27, 4(%r19)		# save in normal location	\n" \
+"	bl	1f							\n" \
+"	# this instruction never gets executed but can be used		\n" \
+"	# to find the virtual address where the page is loaded.		\n" \
+"	bl _GLOBAL_OFFSET_TABLE_@local-4				\n" \
+"	bl _DYNAMIC@local						\n" \
+"1:									\n" \
+"	mflr	%r6		# this stores where we are (+4)		\n" \
+"	lwz	%r18, 0(%r6)	# load the instruction at offset_sym	\n" \
+"				# it contains an offset to the location	\n" \
+"				# of the GOT.				\n" \
+"									\n" \
+"	rlwinm %r18,%r18,0,8,30 # mask off offset portion of the instr. \n" \
+"									\n" \
+"	/*								\n" \
+"	 * these adds effectively calculate the value the		\n" \
+"	 * bl _GLOBAL_OFFSET_TABLE_@local-4				\n" \
+"	 * operation that would be below would calculate.		\n" \
+"	 */								\n" \
+"	add	%r28, %r18, %r6						\n" \
+"									\n" \
+"	/* mprotect GOT-4 for correct execution of blrl instruction */	\n" \
+"	li	%r0, " STR(SYS_mprotect) "				\n" \
+"	mr	%r3, %r28						\n" \
+"	li	%r4, 4							\n" \
+"	li	%r5, 7	/* (PROT_READ|PROT_WRITE|PROT_EXEC) */		\n" \
+"	sc								\n" \
+"									\n" \
+"	li	%r0, 0							\n" \
+"	# flush the blrl instruction out of the data cache		\n" \
+"	dcbf	%r6, %r18						\n" \
+"	sync								\n" \
+"	isync								\n" \
+"	# make certain that the got table addr is not in the icache	\n" \
+"	icbi	%r6, %r18						\n" \
+"	sync								\n" \
+"	isync								\n" \
+"									\n" \
+"	/* This calculates the address of _DYNAMIC the same way		\n" \
+"	 * that the GLOBAL_OFFSET_TABLE was calculated.			\n" \
+"	 */								\n" \
+"	lwz	%r18, 4(%r6)						\n" \
+"	rlwinm	%r18,%r18,0,8,30 # mask off offset portion of the instr. \n" \
+"	add	%r8, %r18, %r6	# address of _DYNAMIC (arg6 for _dl_boot) \n" \
+"	addi	%r18, %r8, 4	# correction.				\n" \
+"	lwz	%r4, 4(%r28)	# load addr of _DYNAMIC according to got. \n" \
+"	sub	%r4, %r18, %r4	# determine load offset			\n" \
+"									\n" \
+"	subi	%r3, %r21, 4	# Get stack pointer (arg0 for _dl_boot). \n" \
+"	addi	%r4, %r1, 8	# dl_data				\n" \
+"	mr	%r5, %r18	# dynamicp				\n" \
+"									\n" \
+"	bl	_dl_boot_bind@local					\n" \
+"									\n" \
+"	mtlr %r27							\n" \
+"	# move argument registers back from saved registers		\n" \
+"	mr %r3, %r20							\n" \
+"	mr %r4, %r21							\n" \
+"	mr %r5, %r22							\n" \
+"	li %r6, 0							\n" \
+"	b ___start							\n" \
+"									\n" \
+"	.text								\n" \
+"	.align 2							\n" \
+"	.globl	_dl_exit						\n" \
+"	.type	_dl_exit, @function					\n" \
+"_dl_exit:								\n" \
+"	li	%r0, " STR(SYS_exit) "					\n" \
+"	sc								\n" \
+"	blr								\n" \
+"									\n" \
+"	.text								\n" \
+"	.align 2							\n" \
+"	.globl	_dl_printf						\n" \
+"	.type	_dl_printf, @function					\n" \
+"_dl_printf:								\n" \
+"	blr								\n" \
+)