When GCC optimizes for size, it branches to libgcc's _restgpr_N_x routines to restore non-volatile registers. U-Boot's private libgcc lacks these routines, so builds with CONFIG_USE_PRIVATE_LIBGCC=y fail to link with Debian's GCC 14.2, for example qemu-ppce500:
undefined reference to `_restgpr_31_x' Copy the 32-bit integer register save and restore routines from Linux's arch/powerpc/lib/crtsavres.S (v7.3-rc5), following the private libgcc's existing approach for shift routines. Put each group of routines in its own section so --gc-sections can discard unused groups. Linux's CONFIG_CC_OPTIMIZE_FOR_SIZE condition is then not needed. Signed-off-by: Josef Schlehofer <[email protected]> Cc: Tom Rini <[email protected]> Cc: Christophe Leroy <[email protected]> Cc: Marek Behún <[email protected]> --- Changes in v2: - new patch The routines assemble to the same code as crtsavgpr.o, crtresgpr.o and crtresxgpr.o in Debian's libgcc 14.2. --- arch/powerpc/lib/Makefile | 3 +- arch/powerpc/lib/crtsavres.S | 213 +++++++++++++++++++++++++++++++++++ 2 files changed, 215 insertions(+), 1 deletion(-) create mode 100644 arch/powerpc/lib/crtsavres.S diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile index a3048975ae7..90f0e1e5fa9 100644 --- a/arch/powerpc/lib/Makefile +++ b/arch/powerpc/lib/Makefile @@ -5,7 +5,8 @@ ## Build a couple of necessary functions into a private libgcc ## if the user asked for it -lib-$(CONFIG_USE_PRIVATE_LIBGCC) += _ashldi3.o _ashrdi3.o _lshrdi3.o +lib-$(CONFIG_USE_PRIVATE_LIBGCC) += _ashldi3.o _ashrdi3.o _lshrdi3.o \ + crtsavres.o MINIMAL= diff --git a/arch/powerpc/lib/crtsavres.S b/arch/powerpc/lib/crtsavres.S new file mode 100644 index 00000000000..8c35eedecb6 --- /dev/null +++ b/arch/powerpc/lib/crtsavres.S @@ -0,0 +1,213 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Out-of-line integer register save and restore routines, which GCC calls + * from function prologues and epilogues when it optimizes for size. + * + * This code was copied from crtsavres.S in arch/powerpc/lib of the Linux + * kernel sources (v7.3-rc5, last changed by commit 699d53f04829 + * ("powerpc/vdso32: Fix use of crtsavres for PPC64")): the 32-bit integer + * register routines, without the CONFIG_CC_OPTIMIZE_FOR_SIZE condition. + * Each group of routines is in a section of its own, so that --gc-sections + * drops the groups that nothing calls. The source file copyrights are as + * follows: + * + * Copyright (C) 1995, 1996, 1998, 2000, 2001 Free Software Foundation, Inc. + * Copyright 2008 Freescale Semiconductor, Inc. + * Written By Michael Meissner + * + * Based on gcc/config/rs6000/crtsavres.asm from gcc + */ + +#include <asm/processor.h> + +/* Routines for saving integer registers, called by the compiler. */ +/* Called with r11 pointing to the stack header word of the caller of the */ +/* function, just beyond the end of the integer save area. */ + + .section ".text._savegpr_14","ax",@progbits + .align 2 + +_GLOBAL(_savegpr_14) +_GLOBAL(_save32gpr_14) + stw 14,-72(11) /* save gp registers */ +_GLOBAL(_savegpr_15) +_GLOBAL(_save32gpr_15) + stw 15,-68(11) +_GLOBAL(_savegpr_16) +_GLOBAL(_save32gpr_16) + stw 16,-64(11) +_GLOBAL(_savegpr_17) +_GLOBAL(_save32gpr_17) + stw 17,-60(11) +_GLOBAL(_savegpr_18) +_GLOBAL(_save32gpr_18) + stw 18,-56(11) +_GLOBAL(_savegpr_19) +_GLOBAL(_save32gpr_19) + stw 19,-52(11) +_GLOBAL(_savegpr_20) +_GLOBAL(_save32gpr_20) + stw 20,-48(11) +_GLOBAL(_savegpr_21) +_GLOBAL(_save32gpr_21) + stw 21,-44(11) +_GLOBAL(_savegpr_22) +_GLOBAL(_save32gpr_22) + stw 22,-40(11) +_GLOBAL(_savegpr_23) +_GLOBAL(_save32gpr_23) + stw 23,-36(11) +_GLOBAL(_savegpr_24) +_GLOBAL(_save32gpr_24) + stw 24,-32(11) +_GLOBAL(_savegpr_25) +_GLOBAL(_save32gpr_25) + stw 25,-28(11) +_GLOBAL(_savegpr_26) +_GLOBAL(_save32gpr_26) + stw 26,-24(11) +_GLOBAL(_savegpr_27) +_GLOBAL(_save32gpr_27) + stw 27,-20(11) +_GLOBAL(_savegpr_28) +_GLOBAL(_save32gpr_28) + stw 28,-16(11) +_GLOBAL(_savegpr_29) +_GLOBAL(_save32gpr_29) + stw 29,-12(11) +_GLOBAL(_savegpr_30) +_GLOBAL(_save32gpr_30) + stw 30,-8(11) +_GLOBAL(_savegpr_31) +_GLOBAL(_save32gpr_31) + stw 31,-4(11) + blr + +/* Routines for restoring integer registers, called by the compiler. */ +/* Called with r11 pointing to the stack header word of the caller of the */ +/* function, just beyond the end of the integer restore area. */ + + .section ".text._restgpr_14","ax",@progbits + .align 2 + +_GLOBAL(_restgpr_14) +_GLOBAL(_rest32gpr_14) + lwz 14,-72(11) /* restore gp registers */ +_GLOBAL(_restgpr_15) +_GLOBAL(_rest32gpr_15) + lwz 15,-68(11) +_GLOBAL(_restgpr_16) +_GLOBAL(_rest32gpr_16) + lwz 16,-64(11) +_GLOBAL(_restgpr_17) +_GLOBAL(_rest32gpr_17) + lwz 17,-60(11) +_GLOBAL(_restgpr_18) +_GLOBAL(_rest32gpr_18) + lwz 18,-56(11) +_GLOBAL(_restgpr_19) +_GLOBAL(_rest32gpr_19) + lwz 19,-52(11) +_GLOBAL(_restgpr_20) +_GLOBAL(_rest32gpr_20) + lwz 20,-48(11) +_GLOBAL(_restgpr_21) +_GLOBAL(_rest32gpr_21) + lwz 21,-44(11) +_GLOBAL(_restgpr_22) +_GLOBAL(_rest32gpr_22) + lwz 22,-40(11) +_GLOBAL(_restgpr_23) +_GLOBAL(_rest32gpr_23) + lwz 23,-36(11) +_GLOBAL(_restgpr_24) +_GLOBAL(_rest32gpr_24) + lwz 24,-32(11) +_GLOBAL(_restgpr_25) +_GLOBAL(_rest32gpr_25) + lwz 25,-28(11) +_GLOBAL(_restgpr_26) +_GLOBAL(_rest32gpr_26) + lwz 26,-24(11) +_GLOBAL(_restgpr_27) +_GLOBAL(_rest32gpr_27) + lwz 27,-20(11) +_GLOBAL(_restgpr_28) +_GLOBAL(_rest32gpr_28) + lwz 28,-16(11) +_GLOBAL(_restgpr_29) +_GLOBAL(_rest32gpr_29) + lwz 29,-12(11) +_GLOBAL(_restgpr_30) +_GLOBAL(_rest32gpr_30) + lwz 30,-8(11) +_GLOBAL(_restgpr_31) +_GLOBAL(_rest32gpr_31) + lwz 31,-4(11) + blr + +/* Routines for restoring integer registers, called by the compiler. */ +/* Called with r11 pointing to the stack header word of the caller of the */ +/* function, just beyond the end of the integer restore area. */ + + .section ".text._restgpr_14_x","ax",@progbits + .align 2 + +_GLOBAL(_restgpr_14_x) +_GLOBAL(_rest32gpr_14_x) + lwz 14,-72(11) /* restore gp registers */ +_GLOBAL(_restgpr_15_x) +_GLOBAL(_rest32gpr_15_x) + lwz 15,-68(11) +_GLOBAL(_restgpr_16_x) +_GLOBAL(_rest32gpr_16_x) + lwz 16,-64(11) +_GLOBAL(_restgpr_17_x) +_GLOBAL(_rest32gpr_17_x) + lwz 17,-60(11) +_GLOBAL(_restgpr_18_x) +_GLOBAL(_rest32gpr_18_x) + lwz 18,-56(11) +_GLOBAL(_restgpr_19_x) +_GLOBAL(_rest32gpr_19_x) + lwz 19,-52(11) +_GLOBAL(_restgpr_20_x) +_GLOBAL(_rest32gpr_20_x) + lwz 20,-48(11) +_GLOBAL(_restgpr_21_x) +_GLOBAL(_rest32gpr_21_x) + lwz 21,-44(11) +_GLOBAL(_restgpr_22_x) +_GLOBAL(_rest32gpr_22_x) + lwz 22,-40(11) +_GLOBAL(_restgpr_23_x) +_GLOBAL(_rest32gpr_23_x) + lwz 23,-36(11) +_GLOBAL(_restgpr_24_x) +_GLOBAL(_rest32gpr_24_x) + lwz 24,-32(11) +_GLOBAL(_restgpr_25_x) +_GLOBAL(_rest32gpr_25_x) + lwz 25,-28(11) +_GLOBAL(_restgpr_26_x) +_GLOBAL(_rest32gpr_26_x) + lwz 26,-24(11) +_GLOBAL(_restgpr_27_x) +_GLOBAL(_rest32gpr_27_x) + lwz 27,-20(11) +_GLOBAL(_restgpr_28_x) +_GLOBAL(_rest32gpr_28_x) + lwz 28,-16(11) +_GLOBAL(_restgpr_29_x) +_GLOBAL(_rest32gpr_29_x) + lwz 29,-12(11) +_GLOBAL(_restgpr_30_x) +_GLOBAL(_rest32gpr_30_x) + lwz 30,-8(11) +_GLOBAL(_restgpr_31_x) +_GLOBAL(_rest32gpr_31_x) + lwz 0,4(11) + lwz 31,-4(11) + mtlr 0 + mr 1,11 + blr -- 2.54.0 (Apple Git-157)
