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# Put the call_via_rx code into each executable - call_via_ip cannot
# possibly work if called through the PLT! ldso requires this code
# too as it is not linked with the crt stuff and thumb ldso does
# make calls via a register.
#
# The patch puts the code into crti.S so that it is linked into
# every normally built application (if thumb or interworking is
# selected). This is only 30 extra bytes and it works - the previous
# code did not because nothing both implemented and exported the
# APIs (they were in libgcc, but not in the version script).
#
# crti.S and crtn.S is also brought up to date with GCC 3.4.4 - this
# is essential for thumb support because the .init and .fini sections
# must use arm or thumb code to match the compilation of the libraries.
#
# Note that code which pushes stuff into .init or .fini must be
# compiled with or without -mthumb to match the uclibc compilation -
# and gcc itself (which does do this) must therefore be compiled to
# match.
#
--- uClibc-0.9.28/.pc/thumb-call-via-rx.patch/libc/sysdeps/linux/arm/crti.S 2005-08-17 15:49:41.000000000 -0700
+++ uClibc-0.9.28/libc/sysdeps/linux/arm/crti.S 2005-09-21 19:15:19.996721584 -0700
@@ -1,26 +1,86 @@
.file "initfini.c"
.section .init
- .align 2
.global _init
.type _init, %function
+#if defined __thumb__
+ .align 1
+ .thumb
+ .thumb_func
_init:
- @ args = 0, pretend = 0, frame = 0
- @ frame_needed = 0, uses_anonymous_args = 0
- str lr, [sp, #-4]!
-
- .align 2
-
-
- .section .fini
+ push {r4-r7, lr}
+#else
.align 2
+ .arm
+_init:
+ @ gcc 3.3.2 didn't create a stack frame, gcc 3.4.4 does -
+ @ presumably 3.4.4 can put stuff into .init which requires
+ @ the arguments to be saved. This code is copied from 3.4.4
+ mov ip, sp
+ stmdb sp!, {r4, r5, r6, r7, r8, r9, sl, fp, ip, lr, pc}
+ sub fp, ip, #4
+#endif
+
+
+ .section .fini
.global _fini
.type _fini, %function
+#if defined __thumb__
+ .align 1
+ .thumb
+ .thumb_func
_fini:
- @ args = 0, pretend = 0, frame = 0
- @ frame_needed = 0, uses_anonymous_args = 0
- str lr, [sp, #-4]!
- .align 2
-
-
+ push {r4-r7, lr}
+#else
+ .align 2
+ .arm
+_fini:
+ mov ip, sp
+ stmdb sp!, {r4, r5, r6, r7, r8, r9, sl, fp, ip, lr, pc}
+ sub fp, ip, #4
+#endif
+
+
+#if (defined __thumb__ || defined __THUMB_INTERWORK__) && (defined __ARM_ARCH_4T__ || defined __ARM_ARCH_5T__ || defined __ARM_ARCH_5TE__)
+ @ To support thumb code it is currently necessary to have the _call_via_rX
+ @ functions exposed to the linker for any program or shared library. PLT
+ @ references are inadequate - the PLT zaps ip and therefore breaks _call_via_ip
+ @ (and the compiler does generate this). It is simpler to put all the
+ @ required code in here - it only amounts to 60 bytes overhead.
+ @NOTE: it would be better to have the compiler generate this stuff as
+ @ required...
+ .section ".text"
+ .align 0
+ .force_thumb
+
+.macro call_via register
+ .global _call_via_\register
+ .type _call_via_\register, %function
+ .weak _call_via_\register
+ .hidden _call_via_\register
+ .thumb_func
+_call_via_\register:
+ bx \register
+ nop
+ .size _call_via_\register, . - _call_via_\register
+.endm
+
+ @ and calls for the 15 general purpose registers (2 bytes each).
+ call_via r0
+ call_via r1
+ call_via r2
+ call_via r3
+ call_via r4
+ call_via r5
+ call_via r6
+ call_via r7
+ call_via r8
+ call_via r9
+ call_via sl
+ call_via fp
+ call_via ip
+ call_via sp
+ call_via lr
+#endif
+
.ident "GCC: (GNU) 3.3.2 20031005 (Debian prerelease)"
--- uClibc-0.9.28/libc/sysdeps/linux/arm/crtn.S.orig 2005-09-20 16:39:20.010925582 -0700
+++ uClibc-0.9.28/libc/sysdeps/linux/arm/crtn.S 2005-09-20 17:00:51.700206464 -0700
@@ -1,17 +1,34 @@
.file "initfini.c"
.section .init
- .align 2
.global _init
.type _init, %function
- ldr pc, [sp], #4
+#if defined __thumb__
+ .align 1
+ .thumb
+ @ this will not work on ARMv4T, but lots of stuff
+ @ in here won't work there anyway...
+ pop {r4-r7, pc}
+#else
+ .align 2
+ .arm
+ ldmdb fp, {r4, r5, r6, r7, r8, r9, sl, fp, sp, pc}
+#endif
.size _init, .-_init
.section .fini
- .align 2
.global _fini
.type _fini, %function
- ldr pc, [sp], #4
+#if defined __thumb__
+ .align 1
+ .thumb
+ pop {r4-r7, pc}
+#else
+ .align 2
+ .arm
+ ldmdb fp, {r4, r5, r6, r7, r8, r9, sl, fp, sp, pc}
+#endif
.size _fini, .-_fini
+ @ In fact this is modified to 3.4.4
.ident "GCC: (GNU) 3.3.2 20031005 (Debian prerelease)"
--- uClibc-0.9.28/.pc/thumb-call-via-rx.patch/ldso/ldso/arm/dl-syscalls.h 2005-08-17 15:49:41.000000000 -0700
+++ uClibc-0.9.28/ldso/ldso/arm/dl-syscalls.h 2005-09-21 19:17:01.143086323 -0700
@@ -4,3 +4,39 @@
#define __set_errno(X) {(_dl_errno) = (X);}
#include "sys/syscall.h"
+/* _call_via_rX calls are used in thumb ldso because of calls via
+ * function pointers, but ldso is not linked with anything which
+ * provides them, so define them here (only required for thumb).
+ */
+#if defined(__thumb__)
+asm(
+ ".macro call_via register\n"
+ " .global _call_via_\\register\n"
+ " .hidden _call_via_\\register\n"
+ " .type _call_via_\\register, %function\n"
+ " .thumb_func\n"
+ "_call_via_\\register:\n"
+ " bx \\register\n"
+ " .size _call_via_\\register, . - _call_via_\\register\n"
+ ".endm\n"
+
+ ".text\n"
+ ".thumb\n"
+ ".align 1\n"
+ " call_via r0\n"
+ " call_via r1\n"
+ " call_via r2\n"
+ " call_via r3\n"
+ " call_via r4\n"
+ " call_via r5\n"
+ " call_via r6\n"
+ " call_via r7\n"
+ " call_via r8\n"
+ " call_via r9\n"
+ " call_via r10\n"
+ " call_via r11\n"
+ " call_via r12\n"
+ " call_via r13\n"
+ " call_via r14\n"
+);
+#endif
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