1 files changed, 217 insertions, 0 deletions
diff --git a/ports/sysdeps/arm/dl-trampoline.S b/ports/sysdeps/arm/dl-trampoline.S
new file mode 100644
index 0000000000..370bda3467
--- /dev/null
+++ b/ports/sysdeps/arm/dl-trampoline.S
@@ -0,0 +1,217 @@
+/* PLT trampolines.  ARM version.
+   Copyright (C) 2005, 2010 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <sysdep.h>
+#include <libc-symbols.h>
+
+#if defined(__USE_BX__)
+#define BX(x) bx	x
+#else
+#define BX(x) mov	pc, x
+#endif
+
+	.text
+	.globl _dl_runtime_resolve
+	.type _dl_runtime_resolve, #function
+	.cfi_sections .debug_frame
+	cfi_startproc
+	.align 2
+_dl_runtime_resolve:
+	cfi_adjust_cfa_offset (4)
+	cfi_rel_offset (lr, 0)
+
+	@ we get called with
+	@ 	stack[0] contains the return address from this call
+	@	ip contains &GOT[n+3] (pointer to function)
+	@	lr points to &GOT[2]
+
+	@ Save arguments.  We save r4 to realign the stack.
+	stmdb	sp!,{r0-r4}
+	cfi_adjust_cfa_offset (20)
+	cfi_rel_offset (r0, 0)
+	cfi_rel_offset (r1, 4)
+	cfi_rel_offset (r2, 8)
+	cfi_rel_offset (r3, 12)
+
+	@ get pointer to linker struct
+	ldr	r0, [lr, #-4]
+
+	@ prepare to call _dl_fixup()
+	@ change &GOT[n+3] into 8*n        NOTE: reloc are 8 bytes each
+	sub	r1, ip, lr
+	sub	r1, r1, #4
+	add	r1, r1, r1
+
+	@ call fixup routine
+	bl	_dl_fixup
+
+	@ save the return
+	mov	ip, r0
+
+	@ get arguments and return address back.  We restore r4
+	@ only to realign the stack.
+	ldmia	sp!, {r0-r4,lr}
+	cfi_adjust_cfa_offset (-24)
+
+	@ jump to the newly found address
+	BX(ip)
+
+	cfi_endproc
+	.size _dl_runtime_resolve, .-_dl_runtime_resolve
+
+#ifndef PROF
+	.globl _dl_runtime_profile
+	.type _dl_runtime_profile, #function
+	.cfi_sections .debug_frame
+	cfi_startproc
+	.align 2
+_dl_runtime_profile:
+	cfi_adjust_cfa_offset (4)
+	cfi_rel_offset (lr, 0)
+
+	@ we get called with
+	@ 	stack[0] contains the return address from this call
+	@	ip contains &GOT[n+3] (pointer to function)
+	@	lr points to &GOT[2]
+
+	@ Stack layout:
+	@ 212 - saved lr
+	@ 208 - framesize returned from pltenter
+	@ 16 - La_arm_regs
+	@ 8 - Saved two arguments to _dl_profile_fixup
+	@ 4 - Saved result of _dl_profile_fixup
+	@ 0 - outgoing argument to _dl_profile_fixup
+	@ For now, we only save the general purpose registers.
+
+	sub	sp, sp, #196
+	cfi_adjust_cfa_offset (196)
+	stmia	sp, {r0-r3}
+	cfi_rel_offset (r0, 0)
+	cfi_rel_offset (r1, 4)
+	cfi_rel_offset (r2, 8)
+	cfi_rel_offset (r3, 12)
+
+	sub	sp, sp, #16
+	cfi_adjust_cfa_offset (16)
+
+	@ Save sp and lr.
+	add	r0, sp, #216
+	str	r0, [sp, #32]
+	ldr	r2, [sp, #212]
+	str	r2, [sp, #36]
+
+	@ get pointer to linker struct
+	ldr	r0, [lr, #-4]
+
+	@ prepare to call _dl_profile_fixup()
+	@ change &GOT[n+3] into 8*n        NOTE: reloc are 8 bytes each
+	sub	r1, ip, lr
+	sub	r1, r1, #4
+	add	r1, r1, r1
+
+	@ Save these two arguments for pltexit.
+	add	r3, sp, #8
+	stmia	r3!, {r0,r1}
+
+	@ Set up extra args for _dl_profile_fixup.
+	@ r2 and r3 are already loaded.
+	add	ip, sp, #208
+	str	ip, [sp, #0]
+
+	@ call profiling fixup routine
+	bl	_dl_profile_fixup
+
+	@ The address to call is now in r0.
+
+	@ Check whether we're wrapping this function.
+	ldr	ip, [sp, #208]
+	cmp	ip, #0
+	bge	1f
+	cfi_remember_state
+
+	@ save the return
+	mov	ip, r0
+
+	@ get arguments and return address back
+	add	sp, sp, #16
+	cfi_adjust_cfa_offset (-16)
+	ldmia	sp, {r0-r3,sp,lr}
+	cfi_adjust_cfa_offset (-200)
+
+	@ jump to the newly found address
+	BX(ip)
+
+	cfi_restore_state
+1:
+	@ The new frame size is in ip.
+
+	@ New stack layout:
+	@ 268 - saved r7
+	@ 264 - saved result of _dl_profile_fixup
+	@ 72 - La_arm_regs
+	@ 64 - Saved two arguments to _dl_profile_fixup
+	@ 0 - La_arm_retval
+	@ For now, we only save the general purpose registers.
+
+	@ Build the new frame.
+	str	r7, [sp, #212]
+	cfi_rel_offset (r7, 212)
+	sub	r7, sp, #56
+	cfi_def_cfa_register (r7)
+	cfi_adjust_cfa_offset (56)
+	sub	sp, sp, ip
+	bic	sp, sp, #7
+
+	@ Save the _dl_profile_fixup result around the call to memcpy.
+	str	r0, [r7, #264]
+
+	@ Copy the stack arguments.
+	mov	r0, sp
+	add	r1, r7, #272
+	mov	r2, ip
+	bl	memcpy
+
+	@ Call the function.
+	add	ip, r7, #72
+	ldmia	ip, {r0-r3}
+	ldr	ip, [r7, #264]
+	mov	lr, pc
+	BX(ip)
+	stmia	r7, {r0-r3}
+
+	@ Call pltexit.
+	add	ip, r7, #64
+	ldmia	ip, {r0,r1}
+	add	r2, r7, #72
+	add	r3, r7, #0
+	bl	_dl_call_pltexit
+
+	@ Return to caller.
+	ldmia	r7, {r0-r3}
+	mov	sp, r7
+	cfi_def_cfa_register (sp)
+	ldr	r7, [sp, #268]
+	ldr	lr, [sp, #92]
+	add	sp, sp, #272
+	cfi_adjust_cfa_offset (-272)
+	BX(lr)
+
+	cfi_endproc
+	.size _dl_runtime_profile, .-_dl_runtime_profile
+#endif
+	.previous