[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


More information about the U-Boot mailing list