+/* SPDX-License-Identifier: GPL-2.0+ */
/*
* U-Boot - x86 Startup Code
*
+ * This is always the first code to run from the U-Boot source. To spell it out:
+ *
+ * 1. When TPL (Tertiary Program Loader) is enabled, the boot flow is
+ * TPL->SPL->U-Boot and this file is used for TPL. Then start_from_tpl.S is used
+ * for SPL and start_from_spl.S is used for U-Boot proper.
+ *
+ * 2. When SPL (Secondary Program Loader) is enabled, but not TPL, the boot
+ * flow is SPL->U-Boot and this file is used for SPL. Then start_from_spl.S is
+ * used for U-Boot proper.
+ *
+ * 3. When neither TPL nor SPL is used, this file is used for U-Boot proper.
+ *
* (C) Copyright 2008-2011
* Graeme Russ, <graeme.russ@gmail.com>
*
* (C) Copyright 2002
* Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
- *
- * SPDX-License-Identifier: GPL-2.0+
*/
#include <config.h>
#include <asm/processor-flags.h>
#include <generated/generic-asm-offsets.h>
#include <generated/asm-offsets.h>
+#include <linux/linkage.h>
-.section .text
+.section .text.start
.code32
.globl _start
.type _start, @function
movl %eax, %cr0
wbinvd
- /* Tell 32-bit code it is being entered from an in-RAM copy */
- movl $GD_FLG_WARM_BOOT, %ebx
-
/*
* Zero the BIST (Built-In Self Test) value since we don't have it.
* It must be 0 or the previous loader would have reported an error.
.align 4
.long 0x12345678
_start:
- /*
- * This is the 32-bit cold-reset entry point, coming from start16.
- * Set %ebx to GD_FLG_COLD_BOOT to indicate this.
- */
- movl $GD_FLG_COLD_BOOT, %ebx
+ /* This is the 32-bit cold-reset entry point, coming from start16 */
/* Save BIST */
movl %eax, %ebp
/* Save table pointer */
movl %ecx, %esi
+#ifdef CONFIG_X86_LOAD_FROM_32_BIT
+ lgdt gdt_ptr2
+#endif
+
/* Load the segement registers to match the GDT loaded in start16.S */
movl $(X86_GDT_ENTRY_32BIT_DS * X86_GDT_ENTRY_SIZE), %eax
movw %ax, %fs
jmp car_init
.globl car_init_ret
car_init_ret:
-#ifndef CONFIG_HAVE_FSP
+#ifdef CONFIG_USE_CAR
/*
* We now have CONFIG_SYS_CAR_SIZE bytes of Cache-As-RAM (or SRAM,
* or fully initialised SDRAM - we really don't care which)
/* Get address of global_data */
mov %fs:0, %edx
-#ifdef CONFIG_HAVE_FSP
+#if defined(CONFIG_USE_HOB) && !defined(CONFIG_USE_CAR)
/* Store the HOB list if we have one */
test %esi, %esi
jz skip_hob
movl %esi, GD_HOB_LIST(%edx)
+#ifdef CONFIG_HAVE_FSP
/*
* After fsp_init() returns, the stack has already been switched to a
* place within system memory as defined by CONFIG_FSP_TEMP_RAM_ADDR.
*/
subl $CONFIG_FSP_SYS_MALLOC_F_LEN, %esp
movl %esp, GD_MALLOC_BASE(%edx)
+#endif
skip_hob:
#else
/* Store table pointer */
movl %eax, %esp
/* See if we need to disable CAR */
-.weak car_uninit
- movl $car_uninit, %eax
- cmpl $0, %eax
- jz 1f
-
call car_uninit
-1:
+
/* Re-enter U-Boot by calling board_init_f_r() */
call board_init_f_r
+#ifdef CONFIG_TPL
+.globl jump_to_spl
+.type jump_to_spl, @function
+jump_to_spl:
+ /* Reset stack to the top of CAR space */
+ movl $(CONFIG_SYS_CAR_ADDR + CONFIG_SYS_CAR_SIZE - 4), %esp
+#ifdef CONFIG_DCACHE_RAM_MRC_VAR_SIZE
+ subl $CONFIG_DCACHE_RAM_MRC_VAR_SIZE, %esp
+#endif
+
+ jmp *%eax
+#endif
+
die:
hlt
jmp die
hlt
+WEAK(car_uninit)
+ ret
+ENDPROC(car_uninit)
+
blank_idt_ptr:
.word 0 /* limit */
.long 0 /* base */
.long 0
/* entry addr */
.long CONFIG_SYS_TEXT_BASE
+
+#ifdef CONFIG_X86_LOAD_FROM_32_BIT
+ /*
+ * The following Global Descriptor Table is just enough to get us into
+ * 'Flat Protected Mode' - It will be discarded as soon as the final
+ * GDT is setup in a safe location in RAM
+ */
+gdt_ptr2:
+ .word 0x1f /* limit (31 bytes = 4 GDT entries - 1) */
+ .long gdt_rom2 /* base */
+
+ /* Some CPUs are picky about GDT alignment... */
+ .align 16
+.globl gdt_rom2
+gdt_rom2:
+ /*
+ * The GDT table ...
+ *
+ * Selector Type
+ * 0x00 NULL
+ * 0x08 Unused
+ * 0x10 32bit code
+ * 0x18 32bit data/stack
+ */
+ /* The NULL Desciptor - Mandatory */
+ .word 0x0000 /* limit_low */
+ .word 0x0000 /* base_low */
+ .byte 0x00 /* base_middle */
+ .byte 0x00 /* access */
+ .byte 0x00 /* flags + limit_high */
+ .byte 0x00 /* base_high */
+
+ /* Unused Desciptor - (matches Linux) */
+ .word 0x0000 /* limit_low */
+ .word 0x0000 /* base_low */
+ .byte 0x00 /* base_middle */
+ .byte 0x00 /* access */
+ .byte 0x00 /* flags + limit_high */
+ .byte 0x00 /* base_high */
+
+ /*
+ * The Code Segment Descriptor:
+ * - Base = 0x00000000
+ * - Size = 4GB
+ * - Access = Present, Ring 0, Exec (Code), Readable
+ * - Flags = 4kB Granularity, 32-bit
+ */
+ .word 0xffff /* limit_low */
+ .word 0x0000 /* base_low */
+ .byte 0x00 /* base_middle */
+ .byte 0x9b /* access */
+ .byte 0xcf /* flags + limit_high */
+ .byte 0x00 /* base_high */
+
+ /*
+ * The Data Segment Descriptor:
+ * - Base = 0x00000000
+ * - Size = 4GB
+ * - Access = Present, Ring 0, Non-Exec (Data), Writable
+ * - Flags = 4kB Granularity, 32-bit
+ */
+ .word 0xffff /* limit_low */
+ .word 0x0000 /* base_low */
+ .byte 0x00 /* base_middle */
+ .byte 0x93 /* access */
+ .byte 0xcf /* flags + limit_high */
+ .byte 0x00 /* base_high */
+#endif
projects / oweals / u-boot.git / blobdiff