1/* SPDX-License-Identifier: GPL-2.0+ */
2/*
3 * 32-bit x86 Startup Code when running from SPL. This is the startup code in
4 * U-Boot proper, when SPL is used.
5
6 * Copyright 2018 Google, Inc
7 * Written by Simon Glass <sjg@chromium.org>
8 */
9
10#include <config.h>
11
12.section .text.start
13.code32
14.globl _start
15.type _start, @function
16_start:
17	/*
18	 * If running from coreboot, CAR is no-longer available. Use the
19	 * existing stack, which is large enough.
20	 */
21	call	locate_coreboot_table
22	cmp	$0, %eax
23	jge	use_existing_stack
24
25	movl	$(CONFIG_SYS_CAR_ADDR + CONFIG_SYS_CAR_SIZE - 4), %eax
26#ifdef CONFIG_DCACHE_RAM_MRC_VAR_SIZE
27	subl	$CONFIG_DCACHE_RAM_MRC_VAR_SIZE, %eax
28#endif
29	jmp	2f
30	/*
31	 * We don't subtract CONFIG_DCACHE_RAM_MRC_VAR_SIZE since memory is
32	 * already set up. This has the happy side-effect of putting gd in a
33	 * new place separate from SPL, so the memset() in
34	 * board_init_f_init_reserve() does not cause any problems (otherwise
35	 * it would zero out the gd and crash)
36	 */
37	/* Set up memory using the existing stack */
38use_existing_stack:
39	mov	%esp, %eax
402:
41	call	board_init_f_alloc_reserve
42	mov	%eax, %esp
43
44	call	board_init_f_init_reserve
45
46#ifdef CONFIG_DEBUG_UART
47	call	debug_uart_init
48#endif
49
50	call	x86_cpu_reinit_f
51	xorl	%eax, %eax
52	call	board_init_f
53	call	board_init_f_r
54
55	/* Should not return here */
56	jmp	.
57
58.globl board_init_f_r_trampoline
59.type board_init_f_r_trampoline, @function
60board_init_f_r_trampoline:
61	/*
62	 * SPL has been executed and SDRAM has been initialised, U-Boot code
63	 * has been copied into RAM, BSS has been cleared and relocation
64	 * adjustments have been made. It is now time to jump into the in-RAM
65	 * copy of U-Boot
66	 *
67	 * %eax = Address of top of new stack
68	 */
69
70	/* Stack grows down from top of SDRAM */
71	movl	%eax, %esp
72
73	/* Re-enter U-Boot by calling board_init_f_r() */
74	call	board_init_f_r
75
76die:
77	hlt
78	jmp	die
79	hlt
80
81	.align 4
82_dt_ucode_base_size:
83	/* These next two fields are filled in by binman */
84.globl ucode_base
85ucode_base:	/* Declared in microcode.h */
86	.long	0			/* microcode base */
87.globl ucode_size
88ucode_size:	/* Declared in microcode.h */
89	.long	0			/* microcode size */
90