x86: Add support for starting from SPL/TPL

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@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index fec14847cc572c439be3579f849f1f563a58d7af..9fd6cf2d3bb76be56310d654bcaeb2668fd4385a 100644 (file)
--- 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 54668aab2404131f80c1e2eb5a55e028fdf74794..85fd5e616ea3af7b9866b7ad3d5e47485ead8d71 100644 (file)
--- 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
new file mode 100644 (file)
index 0000000..4d4e5d0
--- /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@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 (file)
index 0000000..44b5363
--- /dev/null
+++ b/arch/x86/cpu/start_from_tpl.S
@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * 32-bit x86 Startup Code when running from TPL
+ *
+ * Copyright 2018 Google, Inc
+ * Written by Simon Glass <sjg@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
+
+       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:
+       /*
+        * TPL has been executed: SDRAM has been initialised, BSS has been
+        * cleared.
+        *
+        * %eax = Address of top of new stack
+        */
+
+       /* Stack grows down from top of SDRAM */
+       movl    %eax, %esp
+
+       /* Re-enter SPL by calling board_init_f_r() */
+       call    board_init_f_r
+
+die:
+       hlt
+       jmp     die
+       hlt