+/* SPDX-License-Identifier: GPL-2.0+ */
/*
- * U-boot - x86 Startup Code
+ * 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 <version.h>
#include <asm/global_data.h>
#include <asm/post.h>
#include <asm/processor.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
.globl _x86boot_start
_x86boot_start:
/*
- * This is the fail safe 32-bit bootstrap entry point. The
- * following code is not executed from a cold-reset (actually, a
- * lot of it is, but from real-mode after cold reset. It is
- * repeated here to put the board into a state as close to cold
- * reset as necessary)
+ * This is the fail-safe 32-bit bootstrap entry point.
+ *
+ * This code is used when booting from another boot loader like
+ * coreboot or EFI. So we repeat some of the same init found in
+ * start16.
*/
cli
cld
movl %eax, %cr0
wbinvd
- /* Tell 32-bit code it is being entered from an in-RAM copy */
- movw $GD_FLG_WARM_BOOT, %bx
- jmp 1f
-_start:
/*
- * This is the 32-bit cold-reset entry point. Initialize %bx to 0
- * in case we're preceeded by some sort of boot stub.
+ * 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.
*/
- movw $GD_FLG_COLD_BOOT, %bx
-1:
+ movl $0, %ebp
+
+ jmp 1f
+
+ /* Add a way for tools to discover the _start entry point */
+ .align 4
+ .long 0x12345678
+_start:
+ /* This is the 32-bit cold-reset entry point, coming from start16 */
+
/* Save BIST */
movl %eax, %ebp
+1:
+
+ /* Save table pointer */
+ movl %ecx, %esi
- /* Load the segement registes to match the gdt loaded in start16.S */
+#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
movw %ax, %ds
/* Clear the interrupt vectors */
lidt blank_idt_ptr
- /* Early platform init (setup gpio, etc ) */
+ /*
+ * Critical early platform init - generally not used, we prefer init
+ * to happen later when we have a console, in case something goes
+ * wrong.
+ */
jmp early_board_init
.globl early_board_init_ret
early_board_init_ret:
jmp car_init
.globl car_init_ret
car_init_ret:
+#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)
* starting at CONFIG_SYS_CAR_ADDR to be used as a temporary stack
- * and early malloc area. The MRC requires some space at the top.
+ * and early malloc() area. The MRC requires some space at the top.
*
* Stack grows down from top of CAR. We have:
*
* top-> CONFIG_SYS_CAR_ADDR + CONFIG_SYS_CAR_SIZE
* MRC area
- * global_data
- * x86 global descriptor table
+ * global_data with x86 global descriptor table
* early malloc area
* stack
* bottom-> CONFIG_SYS_CAR_ADDR
#ifdef CONFIG_DCACHE_RAM_MRC_VAR_SIZE
subl $CONFIG_DCACHE_RAM_MRC_VAR_SIZE, %esp
#endif
+#else
+ /*
+ * U-Boot enters here twice. For the first time it comes from
+ * car_init_done() with esp points to a temporary stack and esi
+ * set to zero. For the second time it comes from fsp_init_done()
+ * with esi holding the HOB list address returned by the FSP.
+ */
+#endif
+ /* Set up global data */
+ mov %esp, %eax
+ call board_init_f_alloc_reserve
+ mov %eax, %esp
+ call board_init_f_init_reserve
+
+#ifdef CONFIG_DEBUG_UART
+ call debug_uart_init
+#endif
- /* Reserve space on stack for global data */
- subl $GENERATED_GBL_DATA_SIZE, %esp
-
- /* Align global data to 16-byte boundary */
- andl $0xfffffff0, %esp
- post_code(POST_START_STACK)
-
- /* Zero the global data since it won't happen later */
- xorl %eax, %eax
- movl $GENERATED_GBL_DATA_SIZE, %ecx
- movl %esp, %edi
- rep stosb
-
- /* Setup first parameter to setup_gdt, pointer to global_data */
- movl %esp, %eax
-
- /* Reserve space for global descriptor table */
- subl $X86_GDT_SIZE, %esp
-
- /* Align temporary global descriptor table to 16-byte boundary */
- andl $0xfffffff0, %esp
- movl %esp, %ecx
+ /* Get address of global_data */
+ mov %fs:0, %edx
+#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)
-#if defined(CONFIG_SYS_MALLOC_F_LEN)
- subl $CONFIG_SYS_MALLOC_F_LEN, %esp
- movl %eax, %edx
- addl $GD_MALLOC_BASE, %edx
- movl %esp, (%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.
+ * Enlarge the size of malloc() pool before relocation since we have
+ * plenty of memory now.
+ */
+ subl $CONFIG_FSP_SYS_MALLOC_F_LEN, %esp
+ movl %esp, GD_MALLOC_BASE(%edx)
+#endif
+skip_hob:
+#else
+ /* Store table pointer */
+ movl %esi, GD_TABLE(%edx)
#endif
/* Store BIST */
- movl %eax, %edx
- addl $GD_BIST, %edx
- movl %ebp, (%edx)
-
- /* Set second parameter to setup_gdt */
- movl %ecx, %edx
-
- /* Setup global descriptor table so gd->xyz works */
- call setup_gdt
+ movl %ebp, GD_BIST(%edx)
/* Set parameter to board_init_f() to boot flags */
post_code(POST_START_DONE)
xorl %eax, %eax
- /* Enter, U-boot! */
+ /* Enter, U-Boot! */
call board_init_f
/* indicate (lack of) progress */
/* Stack grows down from top of SDRAM */
movl %eax, %esp
- /* Reserve space on stack for global data */
- subl $GENERATED_GBL_DATA_SIZE, %esp
-
- /* Align global data to 16-byte boundary */
- andl $0xfffffff0, %esp
-
- /* Setup first parameter to memcpy (and setup_gdt) */
- movl %esp, %eax
-
- /* Setup second parameter to memcpy */
- fs movl 0, %edx
-
- /* Set third parameter to memcpy */
- movl $GENERATED_GBL_DATA_SIZE, %ecx
-
- /* Copy global data from CAR to SDRAM stack */
- call memcpy
+ /* See if we need to disable CAR */
+ call car_uninit
- /* Reserve space for global descriptor table */
- subl $X86_GDT_SIZE, %esp
-
- /* Align global descriptor table to 16-byte boundary */
- andl $0xfffffff0, %esp
-
- /* Set second parameter to setup_gdt */
- movl %esp, %edx
+ /* Re-enter U-Boot by calling board_init_f_r() */
+ call board_init_f_r
- /* Setup global descriptor table so gd->xyz works */
- call setup_gdt
+#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
- /* Re-enter U-Boot by calling board_init_f_r */
- call board_init_f_r
+ jmp *%eax
+#endif
die:
hlt
jmp die
hlt
+WEAK(car_uninit)
+ ret
+ENDPROC(car_uninit)
+
blank_idt_ptr:
.word 0 /* limit */
.long 0 /* base */
.p2align 2 /* force 4-byte alignment */
+ /* Add a multiboot header so U-Boot can be loaded by GRUB2 */
multiboot_header:
/* magic */
- .long 0x1BADB002
+ .long 0x1badb002
/* flags */
.long (1 << 16)
/* checksum */
.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