Re: [PATCH v2 03/12] arm: arm926ej-s: Add sunxi code

[Andre Przywara <andre.przywara@arm.com>]

On Wed, 26 Jan 2022 08:53:20 -0500
Jesse Taube <mr.bossman075@gmail.com> wrote:

> From: Icenowy Zheng <icenowy@aosc.io>
> 
> Some Allwinner SoCs use ARM926EJ-S core.
> 
> Add Allwinner/sunXi specific code to ARM926EJ-S CPU dircetory.

It looks like we eventually won't need this, since the SPL linker script
is basically identical to the v7 one, and the VBAR access in the FEL
code could be #ifdef'ed. But I see it's not straight-forward to do this
now, so I am OK with this. We can look at cleaning this up later.

> Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
> Signed-off-by: Jesse Taube <Mr.Bossman075@gmail.com>

Reviewed-by: Andre Przywara <andre.przywara@arm.com>

Thanks for the changes!
Andre

> ---
> V1->V2:
> * Fix Copyright notice
> * Remove lowlevel_init
> * Remove replaced timer.c
> * Remove Read CP15 Control Register
> * Remove unused start.c
> ---
>  arch/arm/cpu/arm926ejs/Makefile             |  1 +
>  arch/arm/cpu/arm926ejs/sunxi/Makefile       |  5 +++
>  arch/arm/cpu/arm926ejs/sunxi/config.mk      |  6 +++
>  arch/arm/cpu/arm926ejs/sunxi/fel_utils.S    | 33 ++++++++++++++
>  arch/arm/cpu/arm926ejs/sunxi/u-boot-spl.lds | 48 +++++++++++++++++++++
>  5 files changed, 93 insertions(+)
>  create mode 100644 arch/arm/cpu/arm926ejs/sunxi/Makefile
>  create mode 100644 arch/arm/cpu/arm926ejs/sunxi/config.mk
>  create mode 100644 arch/arm/cpu/arm926ejs/sunxi/fel_utils.S
>  create mode 100644 arch/arm/cpu/arm926ejs/sunxi/u-boot-spl.lds
> 
> diff --git a/arch/arm/cpu/arm926ejs/Makefile b/arch/arm/cpu/arm926ejs/Makefile
> index b901b7c5c9..7f1436d76e 100644
> --- a/arch/arm/cpu/arm926ejs/Makefile
> +++ b/arch/arm/cpu/arm926ejs/Makefile
> @@ -15,6 +15,7 @@ endif
>  obj-$(CONFIG_MX27) += mx27/
>  obj-$(if $(filter mxs,$(SOC)),y) += mxs/
>  obj-$(if $(filter spear,$(SOC)),y) += spear/
> +obj-$(CONFIG_ARCH_SUNXI) += sunxi/
>  
>  # some files can only build in ARM or THUMB2, not THUMB1
>  
> diff --git a/arch/arm/cpu/arm926ejs/sunxi/Makefile b/arch/arm/cpu/arm926ejs/sunxi/Makefile
> new file mode 100644
> index 0000000000..7d8b959dcd
> --- /dev/null
> +++ b/arch/arm/cpu/arm926ejs/sunxi/Makefile
> @@ -0,0 +1,5 @@
> +# SPDX-License-Identifier: GPL-2.0+
> +# (C) Copyright 2012 Henrik Nordstrom <henrik@henriknordstrom.net>
> +
> +obj-y	+= fel_utils.o
> +CFLAGS_fel_utils.o := -marm
> diff --git a/arch/arm/cpu/arm926ejs/sunxi/config.mk b/arch/arm/cpu/arm926ejs/sunxi/config.mk
> new file mode 100644
> index 0000000000..76ffec9df6
> --- /dev/null
> +++ b/arch/arm/cpu/arm926ejs/sunxi/config.mk
> @@ -0,0 +1,6 @@
> +# Build a combined spl + u-boot image
> +ifdef CONFIG_SPL
> +ifndef CONFIG_SPL_BUILD
> +ALL-y += u-boot-sunxi-with-spl.bin
> +endif
> +endif
> diff --git a/arch/arm/cpu/arm926ejs/sunxi/fel_utils.S b/arch/arm/cpu/arm926ejs/sunxi/fel_utils.S
> new file mode 100644
> index 0000000000..08be7ed11a
> --- /dev/null
> +++ b/arch/arm/cpu/arm926ejs/sunxi/fel_utils.S
> @@ -0,0 +1,33 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +/*
> + * Utility functions for FEL mode.
> + *
> + * Copyright (c) 2015 Google, Inc
> + */
> +
> +#include <asm-offsets.h>
> +#include <config.h>
> +#include <asm/system.h>
> +#include <linux/linkage.h>
> +
> +ENTRY(save_boot_params)
> +	ldr	r0, =fel_stash
> +	str	sp, [r0, #0]
> +	str	lr, [r0, #4]
> +	mrs	lr, cpsr		@ Read CPSR
> +	str	lr, [r0, #8]
> +	mrc	p15, 0, lr, c1, c0, 0	@ Read CP15 SCTLR Register
> +	str	lr, [r0, #12]
> +	b	save_boot_params_ret
> +ENDPROC(save_boot_params)
> +
> +ENTRY(return_to_fel)
> +	mov	sp, r0
> +	mov	lr, r1
> +	ldr	r0, =fel_stash
> +	ldr	r1, [r0, #16]
> +	mcr	p15, 0, r1, c1, c0, 0	@ Write CP15 Control Register
> +	ldr	r1, [r0, #12]
> +	msr	cpsr, r1		@ Write CPSR
> +	bx	lr
> +ENDPROC(return_to_fel)
> diff --git a/arch/arm/cpu/arm926ejs/sunxi/u-boot-spl.lds b/arch/arm/cpu/arm926ejs/sunxi/u-boot-spl.lds
> new file mode 100644
> index 0000000000..9a000ac5d3
> --- /dev/null
> +++ b/arch/arm/cpu/arm926ejs/sunxi/u-boot-spl.lds
> @@ -0,0 +1,48 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +/*
> + * (C) Copyright 2018
> + * Icenowy Zheng <icenowy@aosc.io>
> + *
> + * Based on arch/arm/cpu/armv7/sunxi/u-boot-spl.lds:
> + */
> +MEMORY { .sram : ORIGIN = CONFIG_SPL_TEXT_BASE,\
> +		LENGTH = CONFIG_SPL_MAX_SIZE }
> +MEMORY { .sdram : ORIGIN = CONFIG_SPL_BSS_START_ADDR, \
> +		LENGTH = CONFIG_SPL_BSS_MAX_SIZE }
> +
> +OUTPUT_FORMAT("elf32-littlearm", "elf32-littlearm", "elf32-littlearm")
> +OUTPUT_ARCH(arm)
> +ENTRY(_start)
> +SECTIONS
> +{
> +	.text      :
> +	{
> +		__start = .;
> +		*(.vectors)
> +		*(.text*)
> +	} > .sram
> +
> +	. = ALIGN(4);
> +	.rodata : { *(SORT_BY_ALIGNMENT(.rodata*)) } >.sram
> +
> +	. = ALIGN(4);
> +	.data : { *(SORT_BY_ALIGNMENT(.data*)) } >.sram
> +
> +	. = ALIGN(4);
> +	.u_boot_list : {
> +		KEEP(*(SORT(.u_boot_list*)));
> +	} > .sram
> +
> +	. = ALIGN(4);
> +	__image_copy_end = .;
> +	_end = .;
> +
> +	.bss :
> +	{
> +		. = ALIGN(4);
> +		__bss_start = .;
> +		*(.bss*)
> +		. = ALIGN(4);
> +		__bss_end = .;
> +	} > .sdram
> +}