[U-Boot] [PATCH 20/40] x86: Add support for starting from SPL/TPL
Bin Meng
bmeng.cn at gmail.com
Fri Feb 22 07:19:20 UTC 2019
Hi Simon,
On Wed, Jan 30, 2019 at 12:00 PM Simon Glass <sjg at chromium.org> wrote:
>
> When a previous phase of U-Boot has run we need to adjust the init of
> subsequent states to avoid messing up the CPU state.
>
> Add a new version of the start logic for SPL, when it boots from TPL
> (start_from tpl.c) and a new version for U-Boot when it boots from SPL.
>
> Signed-off-by: Simon Glass <sjg at chromium.org>
> ---
>
> arch/x86/Makefile | 12 ++++++
> arch/x86/cpu/Makefile | 15 +++++++-
> arch/x86/cpu/start_from_spl.S | 71 +++++++++++++++++++++++++++++++++++
> arch/x86/cpu/start_from_tpl.S | 50 ++++++++++++++++++++++++
> 4 files changed, 147 insertions(+), 1 deletion(-)
> create mode 100644 arch/x86/cpu/start_from_spl.S
> create mode 100644 arch/x86/cpu/start_from_tpl.S
>
> diff --git a/arch/x86/Makefile b/arch/x86/Makefile
> index fec14847cc..9fd6cf2d3b 100644
> --- a/arch/x86/Makefile
> +++ b/arch/x86/Makefile
> @@ -4,9 +4,21 @@ ifeq ($(CONFIG_EFI_APP),)
> ifdef CONFIG_$(SPL_)X86_64
> head-y := arch/x86/cpu/start64.o
> else
> +ifeq ($(CONFIG_$(SPL_TPL_)X86_16BIT_INIT),y)
> head-y := arch/x86/cpu/start.o
> +else
> +ifndef CONFIG_SPL
> +head-y := arch/x86/cpu/start.o
> +else
> +ifdef CONFIG_SPL_BUILD
> +head-y = arch/x86/cpu/start_from_tpl.o
> +else
> +head-y = arch/x86/cpu/start_from_spl.o
> +endif
> +endif
> endif
> endif
> +endif # EFI
>
> head-$(CONFIG_$(SPL_)X86_16BIT_INIT) += arch/x86/cpu/start16.o
> head-$(CONFIG_$(SPL_)X86_16BIT_INIT) += arch/x86/cpu/resetvec.o
> diff --git a/arch/x86/cpu/Makefile b/arch/x86/cpu/Makefile
> index 54668aab24..85fd5e616e 100644
> --- a/arch/x86/cpu/Makefile
> +++ b/arch/x86/cpu/Makefile
> @@ -9,9 +9,22 @@
> ifeq ($(CONFIG_$(SPL_)X86_64),y)
> extra-y = start64.o
> else
> +ifeq ($(CONFIG_$(SPL_TPL_)X86_16BIT_INIT),y)
> extra-y = start.o
> +else
> +ifndef CONFIG_SPL
> +extra-y = start.o
> +else
> +ifdef CONFIG_SPL_BUILD
> +extra-y = start_from_tpl.o
> +else
> +extra-y = start_from_spl.o
> endif
> -extra-$(CONFIG_$(SPL_)X86_16BIT_INIT) += resetvec.o start16.o
> +endif
> +endif
> +endif
> +
> +extra-$(CONFIG_$(SPL_TPL_)X86_16BIT_INIT) += resetvec.o start16.o
>
> obj-y += cpu.o cpu_x86.o
>
> diff --git a/arch/x86/cpu/start_from_spl.S b/arch/x86/cpu/start_from_spl.S
Is it possible to consolidate start_from_spl.S and start_from_tpl.S
into one file, to save some duplicates?
> new file mode 100644
> index 0000000000..4d4e5d0758
> --- /dev/null
> +++ b/arch/x86/cpu/start_from_spl.S
> @@ -0,0 +1,71 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +/*
> + * 32-bit x86 Startup Code when running from SPL
> + *
> + * Copyright 2018 Google, Inc
> + * Written by Simon Glass <sjg at chromium.org>
> + */
> +
> +#include <config.h>
> +
> +.section .text.start
> +.code32
> +.globl _start
> +.type _start, @function
> +_start:
> + /* Set up memory using the existing stack */
> + movl $(CONFIG_SYS_CAR_ADDR + CONFIG_SYS_CAR_SIZE - 4), %eax
> +#ifdef CONFIG_DCACHE_RAM_MRC_VAR_SIZE
> + subl $CONFIG_DCACHE_RAM_MRC_VAR_SIZE, %eax
> +#endif
> + /*
> + * We don't subject CONFIG_DCACHE_RAM_MRC_VAR_SIZE since memory is
> + * already set up. This has the happy side-effect of putting gd in a
> + * new place separate from SPL, so the memset() in
> + * board_init_f_init_reserve() does not cause any problems (otherwise
> + * it would zero out the gd and crash)
> + */
> + call board_init_f_alloc_reserve
> + mov %eax, %esp
> +
> + call board_init_f_init_reserve
> +
> + xorl %eax, %eax
> + call board_init_f
> + call board_init_f_r
> +
> + /* Should not return here */
> + jmp .
> +
> +.globl board_init_f_r_trampoline
> +.type board_init_f_r_trampoline, @function
> +board_init_f_r_trampoline:
> + /*
> + * SPL has been executed and SDRAM has been initialised, U-Boot code
> + * has been copied into RAM, BSS has been cleared and relocation
> + * adjustments have been made. It is now time to jump into the in-RAM
> + * copy of U-Boot
> + *
> + * %eax = Address of top of new stack
> + */
> +
> + /* Stack grows down from top of SDRAM */
> + movl %eax, %esp
> +
> + /* Re-enter U-Boot by calling board_init_f_r() */
> + call board_init_f_r
> +
> +die:
> + hlt
> + jmp die
> + hlt
> +
> + .align 4
> +_dt_ucode_base_size:
> + /* These next two fields are filled in by binman */
> +.globl ucode_base
> +ucode_base: /* Declared in microcode.h */
> + .long 0 /* microcode base */
> +.globl ucode_size
> +ucode_size: /* Declared in microcode.h */
> + .long 0 /* microcode size */
> diff --git a/arch/x86/cpu/start_from_tpl.S b/arch/x86/cpu/start_from_tpl.S
> new file mode 100644
> index 0000000000..e27f39eddf
> --- /dev/null
> +++ b/arch/x86/cpu/start_from_tpl.S
> @@ -0,0 +1,50 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +/*
> + * 32-bit x86 Startup Code when running from SPL
> + *
> + * Copyright 2018 Google, Inc
> + * Written by Simon Glass <sjg at chromium.org>
> + */
> +
> +#include <config.h>
> +
> +.section .text.start
> +.code32
> +.globl _start
> +.type _start, @function
> +_start:
> + /* Set up memory using the existing stack */
> + mov %esp, %eax
> + call board_init_f_alloc_reserve
> + mov %eax, %esp
> +
> + call board_init_f_init_reserve
> +
missing "xorl %eax, %eax" here
> + call board_init_f
> + call board_init_f_r
> +
> + /* Should not return here */
> + jmp .
> +
> +.globl board_init_f_r_trampoline
> +.type board_init_f_r_trampoline, @function
> +board_init_f_r_trampoline:
> + /*
> + * SPL has been executed and SDRAM has been initialised, U-Boot code
TPL?
> + * has been copied into RAM, BSS has been cleared and relocation
> + * adjustments have been made. It is now time to jump into the in-RAM
> + * copy of U-Boot
> + *
> + * %eax = Address of top of new stack
> + */
> +
> + /* Stack grows down from top of SDRAM */
> + movl %eax, %esp
> +
> + /* Re-enter U-Boot by calling board_init_f_r() */
> + call board_init_f_r
> +
> +die:
> + hlt
> + jmp die
> + hlt
> --
Regards,
Bin
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