GK SDK 源码库: XMIPCLinuxV100R005C00SPC030 (kernel/tools/open_source excluded)

source/bootloader/u-boot-2020.01/arch/x86/cpu/start_from_spl.S

@@ -0,0 +1,73 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * 32-bit x86 Startup Code when running from SPL. This is the startup code in
+ * U-Boot proper, when SPL is used.
+
+ * 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
+
+	call	x86_cpu_reinit_f
+	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 */