[PATCH] sandbox: cleanup linker scripts and sections

[Heinrich Schuchardt]

On 14.06.24 08:53, Ilias Apalodimas wrote:
> commit 6e2228fb052b ("Merge patch series "Clean up arm linker scripts"")
> was cleaning up linker scripts for armv7 and v8 in a similar fashion.
>
> Several commits in the past -- e.g
> commit d0b5d9da5de2 ("arm: make _end compiler-generated")
> was moving symbols to be compiler generated. They were defined as c
> variables in its own section to force the compiler emit relative a
> reference. However, defining those in the linker script will do the
> same thing since [0].
>
> So let's remove the special sections from the linker scripts, the
> variable definitions from sections.c, and define them as a symbols.
> It's worth noting that the linker was discarding the symbols in the
> older binary completely.
>
> - new binary
> $~ aarch64-linux-gnu-readelf -sW u-boot | grep efi_runtim
>     246: 000000000004acbe    13 FUNC    LOCAL  DEFAULT   14 vbe_req_efi_runtime_rand
>    3198: 0000000000318690    16 OBJECT  LOCAL  DEFAULT   29 efi_runtime_mmio
>    6359: 00000000000dedff   217 FUNC    LOCAL  DEFAULT   14 efi_runtime_relocate
>    7942: 00000000003074c0   136 OBJECT  GLOBAL HIDDEN    29 efi_runtime_services
>    8869: 0000000000305e20     0 NOTYPE  GLOBAL DEFAULT   27 __efi_runtime_rel_stop
>    9159: 0000000000305e20     0 NOTYPE  GLOBAL DEFAULT   27 __efi_runtime_stop
>    9410: 0000000000305e20     0 NOTYPE  GLOBAL DEFAULT   27 __efi_runtime_start
>   10137: 00000000005981bd     0 NOTYPE  WEAK   HIDDEN    33 efi_runtime.c.de5bed54
>   10470: 0000000000305e20     0 NOTYPE  GLOBAL DEFAULT   27 __efi_runtime_rel_start
>
> - old binary
> $~ aarch64-linux-gnu-readelf -sW u-boot.old | grep efi_runtim
>     246: 000000000004acbe    13 FUNC    LOCAL  DEFAULT   14 vbe_req_efi_runtime_rand
>    3198: 0000000000318690    16 OBJECT  LOCAL  DEFAULT   29 efi_runtime_mmio
>    6359: 00000000000dedff   221 FUNC    LOCAL  DEFAULT   14 efi_runtime_relocate
>    7942: 00000000003074c0   136 OBJECT  GLOBAL HIDDEN    29 efi_runtime_services
>   10135: 0000000000598320     0 NOTYPE  WEAK   HIDDEN    33 efi_runtime.c.de5bed54
>
> $~ bloat-o-meter u-bool.old u-boot
> add/remove: 0/0 grow/shrink: 1/1 up/down: 7/-4 (3)
> Function                                     old     new   delta
> efi_memory_init                              343     350      +7
> efi_runtime_relocate                         221     217      -4
> Total: Before=2009902, After=2009905, chg +0.00%
>
> [0] binutils commit 6b3b0ab89663 ("Make linker assigned symbol dynamic only for shared object")
>
> Signed-off-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>

Tested with sandbox_defconfig on amd64, arm64, riscv64.

Tested-by: Heinrich Schuchardt <xypron.glpk at gmx.de>

> ---
>   arch/sandbox/cpu/u-boot.lds | 20 ++++----------------
>   arch/sandbox/lib/Makefile   |  2 +-
>   arch/sandbox/lib/sections.c | 13 -------------
>   3 files changed, 5 insertions(+), 30 deletions(-)
>   delete mode 100644 arch/sandbox/lib/sections.c
>
> diff --git a/arch/sandbox/cpu/u-boot.lds b/arch/sandbox/cpu/u-boot.lds
> index 52f13af3742f..6ee8095b6cbb 100644
> --- a/arch/sandbox/cpu/u-boot.lds
> +++ b/arch/sandbox/cpu/u-boot.lds
> @@ -19,30 +19,18 @@ SECTIONS
>   		*(_u_boot_sandbox_getopt_end)
>   	}
>
> -	efi_runtime_start : {
> -		*(___efi_runtime_start)
> -	}
> -
>   	efi_runtime : {
> +                __efi_runtime_start = .;
>   		*(efi_runtime_text)
>   		*(efi_runtime_data)
> -	}
> -
> -	efi_runtime_stop : {
> -		*(___efi_runtime_stop)
> -	}
> -
> -	efi_runtime_rel_start : {
> -		*(___efi_runtime_rel_start)
> +                __efi_runtime_stop = .;
>   	}
>
>   	efi_runtime_rel : {
> +                __efi_runtime_rel_start = .;
>   		*(.relefi_runtime_text)
>   		*(.relefi_runtime_data)
> -	}
> -
> -	efi_runtime_rel_stop : {
> -		*(___efi_runtime_rel_stop)
> +                __efi_runtime_rel_stop = .;
>   	}
>
>   	.dynsym :
> diff --git a/arch/sandbox/lib/Makefile b/arch/sandbox/lib/Makefile
> index a2bc5a7ee60f..d7d15a50bb6c 100644
> --- a/arch/sandbox/lib/Makefile
> +++ b/arch/sandbox/lib/Makefile
> @@ -5,7 +5,7 @@
>   # (C) Copyright 2002-2006
>   # Wolfgang Denk, DENX Software Engineering, wd at denx.de.
>
> -obj-y	+= fdt_fixup.o interrupts.o sections.o
> +obj-y			+= fdt_fixup.o interrupts.o
>   obj-$(CONFIG_PCI)	+= pci_io.o
>   obj-$(CONFIG_CMD_BOOTM) += bootm.o
>   obj-$(CONFIG_CMD_BOOTZ) += bootm.o
> diff --git a/arch/sandbox/lib/sections.c b/arch/sandbox/lib/sections.c
> deleted file mode 100644
> index 2f2f3fbfdb86..000000000000
> --- a/arch/sandbox/lib/sections.c
> +++ /dev/null
> @@ -1,13 +0,0 @@
> -// SPDX-License-Identifier: GPL-2.0+
> -/*
> - * Copyright 2013 Albert ARIBAUD <albert.u.boot at aribaud.net>
> - *
> - */
> -#include <linux/compiler.h>
> -
> -char __efi_runtime_start[0] __section("___efi_runtime_start");
> -char __efi_runtime_stop[0] __section("___efi_runtime_stop");
> -char __efi_runtime_rel_start[0]
> -		__section("___efi_runtime_rel_start");
> -char __efi_runtime_rel_stop[0]
> -		__section("___efi_runtime_rel_stop");
> --
> 2.45.1
>