Add some generic functions to make barebox work on x86.
Signed-off-by: Juergen Beisert <jbe@xxxxxxxxxxxxxx>
---
arch/x86/lib/Makefile | 7 +
arch/x86/lib/gdt.c | 55 +++++++++++++
arch/x86/lib/memory.c | 67 +++++++++++++++
arch/x86/lib/memory16.S | 73 +++++++++++++++++
arch/x86/lib/traveler.S | 183 +++++++++++++++++++++++++++++++++++++++++++
arch/x86/lib/u-boot.lds.S | 194 ++++++++++++++++++++++++++++++++++++++++++++++
6 files changed, 579 insertions(+)
Index: u-boot-2.0.0-rc10/arch/x86/lib/Makefile
===================================================================
--- /dev/null
+++ u-boot-2.0.0-rc10/arch/x86/lib/Makefile
@@ -0,0 +1,7 @@
+extra-$(CONFIG_GENERIC_LINKER_SCRIPT) += u-boot.lds
+obj-y += memory.o
+obj-y += gdt.o
+
+# needed, when running via a 16 bit BIOS
+obj-$(CONFIG_X86_BIOS_BRINGUP) += memory16.o
+obj-$(CONFIG_X86_BIOS_BRINGUP) += traveler.o
Index: u-boot-2.0.0-rc10/arch/x86/lib/u-boot.lds.S
===================================================================
--- /dev/null
+++ u-boot-2.0.0-rc10/arch/x86/lib/u-boot.lds.S
@@ -0,0 +1,194 @@
+/*
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ *
+ */
+
+#undef i386
+#include <asm/u-boot.lds.h>
+
+OUTPUT_FORMAT("elf32-i386", "elf32-i386", "elf32-i386")
+OUTPUT_ARCH(i386)
+ENTRY(_start)
+
+MEMORY
+{
+ mbr(rwx): ORIGIN = TEXT_BASE, LENGTH = 2 * SECTOR_SIZE
+ uboot (rwx) : ORIGIN = TEXT_BASE + SECTOR_SIZE, LENGTH = (256 * 1024 * 1024)
+}
+
+SECTIONS
+{
+#ifdef CONFIG_X86_HDBOOT
+
+ .ramlayout : {
+ boot_stack = INDIRECT_AREA;
+ indirect_area = INDIRECT_AREA;
+ }
+ /* describing the main boot sector */
+ .bootsector : AT (0) {
+ *(.boot_start)
+
+ . = 0x00b;
+ /*
+ * Maybe later on occupied by a "BIOS parameter block". So,
+ * keep it free from code.
+ * - BytesPerSector dw@0x000B
+ * - SectorsPerCluster db@0x000D
+ * - ReservedSectors dw@0x000E
+ * - FatCopies db@0x0010
+ * - RootDirEntries dw@0x0011
+ * - NumSectors dw@0x0013
+ * - MediaType db@0x0015
+ * - SectorsPerFAT dw@0x0016
+ * - SectorsPerTrack dw@0x0018
+ * - NumberOfHeads dw@0x001A
+ * - HiddenSectors dd@0x001C
+ * - SectorsBig dd@0x0020
+ */
+ LONG(0);
+
+ . = 0x024;
+ *(.boot_code)
+ *(.boot_data)
+
+ /*
+ * embed one "Disk Address Packet Structure" into the boot sector
+ * This DAPS points to the 'indirect' sector to give the boot code
+ * an idea what and where to load. Its content must be adapted
+ * to the system it should run on, so, this structure must be
+ * located at a well known offset.
+ */
+ . = PATCH_AREA;
+ indirect_sector_lba = .;
+ SHORT(0x0010); /* size of this structure */
+ SHORT(0x0001); /* one sector */
+ SHORT(indirect_area); /* where to store: offset */
+ SHORT(0x0000); /* where to store: segment */
+ /* the following values are filled by the installer */
+ LONG(0x00000000); /* LBA start lower */
+ LONG(0x00000000); /* LBA start upper */
+
+ /* boot disk number used by upper layers */
+ . = PATCH_AREA + PATCH_AREA_BOOT_DEV;
+ boot_disk = .;
+ BYTE(0x00); /* boot disk number (provided by the BIOS)
+
+ /* information about the persistant environment storage */
+ . = PATCH_AREA + PATCH_AREA_PERS_START;
+ pers_env_storage = .;
+ LONG(0x00000000); /* LBA start lower */
+ LONG(0x00000000); /* LBA start upper */
+
+ . = PATCH_AREA + PATCH_AREA_PERS_SIZE;
+ pers_env_size = .;
+ SHORT(PATCH_AREA_PERS_SIZE_UNUSED); /* size of this area in sectors */
+
+ . = PATCH_AREA + PATCH_AREA_PERS_DRIVE;
+ pers_env_drive = .;
+ BYTE(0x00); /* used drive */
+
+ /* partition table area (fixed location) */
+ . = OFFSET_OF_PARTITION_TABLE;
+ /* create an empty one */
+ LONG(0x00000000); LONG(0x00000000); LONG(0x00000000); LONG(0x00000000);
+ LONG(0x00000000); LONG(0x00000000); LONG(0x00000000); LONG(0x00000000);
+ LONG(0x00000000); LONG(0x00000000); LONG(0x00000000); LONG(0x00000000);
+ LONG(0x00000000); LONG(0x00000000); LONG(0x00000000); LONG(0x00000000);
+
+ /* boot sector signature */
+ . = OFFSET_OF_SIGNATURE;
+ BYTE(0x55);
+ BYTE(0xAA);
+ /* end of the first sector */
+
+ /*
+ * The indirect sector starts here
+ */
+ . = SECTOR_SIZE;
+ BYTE(MARK_DAPS_INVALID); /* mark the first entry invalid */
+ BYTE(0x00);
+ . = SECTOR_SIZE + 496;
+ BYTE(MARK_DAPS_INVALID); /* mark the last entry invalid */
+ BYTE(0x00);
+ . = SECTOR_SIZE + 508;
+ LONG(0x00000000); /* LBA start upper */
+ } > mbr
+
+ /* some real mode bootstrapping */
+ .bootstrapping : AT ( LOADADDR(.bootsector) + SIZEOF(.bootsector) ) {
+ *(.boot.head)
+ *(.boot.text*)
+ *(.boot.rodata*)
+ *(.boot.data*)
+ . = ALIGN(4);
+ } > uboot
+#endif
+
+ /* the main u-boot-v2 part (32 bit) */
+ .text : AT ( LOADADDR(.bootstrapping) + SIZEOF(.bootstrapping) ) {
+ /* do not align here! It may fails with the LOADADDR! */
+ _stext = .;
+ *(.text_entry*)
+ *(.text_bare_init*)
+ *(.text*)
+ . = ALIGN(4);
+ *(.rodata*)
+ . = ALIGN(4);
+ _etext = .; /* End of text and rodata section */
+ } > uboot
+
+ .data : AT ( LOADADDR(.text) + SIZEOF(.text) ) {
+ *(.data*)
+ . = ALIGN(4);
+ } > uboot
+
+ .got : AT ( LOADADDR(.data) + SIZEOF (.data) ) {
+ *(.got*)
+ . = ALIGN(4);
+ } > uboot
+
+ .u_boot_cmd : AT ( LOADADDR(.got) + SIZEOF (.got) ) {
+ __u_boot_cmd_start = .;
+ U_BOOT_CMDS
+ __u_boot_cmd_end = .;
+ . = ALIGN(4);
+ } > uboot
+
+ .u_boot_initcalls : AT ( LOADADDR(.u_boot_cmd) + SIZEOF (.u_boot_cmd) ) {
+ __u_boot_initcalls_start = .;
+ INITCALLS
+ __u_boot_initcalls_end = .;
+ . = ALIGN(4);
+ } > uboot
+
+ .u_boot_symtab : AT ( LOADADDR(.u_boot_initcalls) + SIZEOF (.u_boot_initcalls) ) {
+ __usymtab_start = .;
+ U_BOOT_SYMS
+ __usymtab_end = .;
+ . = ALIGN(4);
+ } > uboot
+
+ .bss : {
+ __bss_start = .;
+ *(.bss*);
+ *( COMMON )
+ __bss_end = .;
+ _end = .;
+ } > uboot
+}
Index: u-boot-2.0.0-rc10/arch/x86/lib/gdt.c
===================================================================
--- /dev/null
+++ u-boot-2.0.0-rc10/arch/x86/lib/gdt.c
@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2009 Juergen Beisert, Pengutronix
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ *
+ */
+
+/**
+ * @file
+ * @brief Definition of the Global Descriptor Table
+ */
+
+#include <types.h>
+#include <asm/modes.h>
+#include <asm/segment.h>
+
+/**
+ * The 'Global Descriptor Table' used in u-boot-v2
+ *
+ * Note: This table must reachable by real and flat mode code
+ */
+uint64_t gdt[] __attribute__((aligned(16))) __bootdata = {
+ /* CS: code, read/execute, 4 GB, base 0 */
+ [GDT_ENTRY_BOOT_CS] = GDT_ENTRY(0xc09b, 0, 0xfffff),
+ /* DS: data, read/write, 4 GB, base 0 */
+ [GDT_ENTRY_BOOT_DS] = GDT_ENTRY(0xc093, 0, 0xfffff),
+ /* CS: for real mode calls */
+ [GDT_ENTRY_REAL_CS] = GDT_ENTRY(0x009E, 0, 0x0ffff),
+ /* DS: for real mode calls */
+ [GDT_ENTRY_REAL_DS] = GDT_ENTRY(0x0092, 0, 0x0ffff),
+ /* TSS: 32-bit tss, 104 bytes, base 4096 */
+ /* We only have a TSS here to keep Intel VT happy;
+ we don't actually use it for anything. */
+ [GDT_ENTRY_BOOT_TSS] = GDT_ENTRY(0x0089, 4096, 103),
+};
+
+/**
+ * Size of the GDT must be known to load it
+ *
+ * Note: This varibale must reachable by real and flat mode code
+ */
+unsigned gdt_size __bootdata = sizeof(gdt);
Index: u-boot-2.0.0-rc10/arch/x86/lib/memory.c
===================================================================
--- /dev/null
+++ u-boot-2.0.0-rc10/arch/x86/lib/memory.c
@@ -0,0 +1,67 @@
+/*
+ * Copyright (C) 2009 Juergen Beisert, Pengutronix
+ *
+ * This code was inspired by the GRUB2 project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ *
+ */
+
+/**
+ * @file
+ * @brief Memory management
+ */
+
+#include <init.h>
+#include <stdio.h>
+#include <mem_malloc.h>
+#include <asm/syslib.h>
+#include <asm-generic/memory_layout.h>
+
+/**
+ * Handling of free memory
+ *
+ * Topics:
+ * - areas used by BIOS code
+ * - The 0xa0000... 0xfffff hole
+ * - memory above 0x100000
+ */
+
+static int x86_mem_malloc_init(void)
+{
+#ifdef CONFIG_MEMORY_LAYOUT_DEFAULT
+ unsigned long memory_size;
+
+ memory_size = bios_get_memsize();
+ memory_size <<= 10; /* BIOS reports in kiB */
+
+ /*
+ * We do not want to conflict with the kernel. So, we keep the
+ * area from 0x100000 ... 0xFFFFFF free from usage
+ */
+ if (memory_size >= (15 * 1024 * 1024 + MALLOC_SIZE))
+ mem_malloc_init((void*)(16 * 1024 * 1024),
+ (void*)(16 * 1024 * 1024) + MALLOC_SIZE);
+ else
+ return -1;
+#else
+ mem_malloc_init((void *)MALLOC_BASE,
+ (void *)(MALLOC_BASE + MALLOC_SIZE));
+#endif
+ return 0;
+}
+
+core_initcall(x86_mem_malloc_init);
Index: u-boot-2.0.0-rc10/arch/x86/lib/traveler.S
===================================================================
--- /dev/null
+++ u-boot-2.0.0-rc10/arch/x86/lib/traveler.S
@@ -0,0 +1,183 @@
+/*
+ * Copyright (C) 2009 Juergen Beisert, Pengutronix
+ *
+ * Mostly stolen from the GRUB2 project
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ *
+ */
+
+/**
+ * @file
+ * @brief Switch from the flat mode world into the real mode world and vice versa
+ *
+ * Note: These functions are *called* and return in a different operating mode
+ */
+
+/**
+ * @fn void real_to_prot(void)
+ * @brief Switch from temp. real mode back to flat mode
+ *
+ * Called from a 32 bit flat mode segment and returns into a 16 bit segment
+ */
+
+/**
+ * @fn void prot_to_real(void)
+ * @brief Switch from flat mode to real mode
+ *
+ * Called from a 16 bit real mode segment and returns into a 32 bit segment
+ */
+
+#ifndef DOXYGEN_SHOULD_SKIP_THIS
+
+#include <asm/modes.h>
+
+ .file "walkyrie.S"
+
+/* keep the current flat mode stack pointer, while playing in real mode */
+ .section .boot.data.protstack
+ .code32
+protstack: .long 4
+/* temp. store */
+return_addr: .long 4
+
+
+ .section .boot.text.real_to_prot, "ax"
+ .code16
+ .globl real_to_prot
+ .type real_to_prot, @function
+
+/* Note: This routine should not change any other standard registers than eax */
+real_to_prot:
+ /*
+ * Always disable the interrupts, when returning to flat mode
+ */
+ cli
+
+ /* turn on protected mode */
+ movl %cr0, %eax
+ orl $0x00000001, %eax
+ movl %eax, %cr0
+
+ /* jump to relocation, flush prefetch queue, and reload %cs */
+ DATA32 ljmp $__BOOT_CS, $return_to_flatmode
+
+/* ----------------------------------------------------------------------- */
+ .section .boot.text.return_to_flatmode, "ax"
+ .type return_to_flatmode, @function
+ .code32
+
+return_to_flatmode:
+ /* reload other segment registers */
+ movw $__BOOT_DS, %ax
+ movw %ax, %ds
+ movw %ax, %es
+ movw %ax, %fs
+ movw %ax, %gs
+ movw %ax, %ss
+
+ /* move the return address from the real mode to the flat mode stack */
+ movl (%esp), %eax
+ movl %eax, return_addr
+
+ /* setup again the flat mode stack */
+ movl protstack, %eax
+ movl %eax, %esp
+ movl %eax, %ebp
+
+ movl return_addr, %eax
+ movl %eax, (%esp)
+
+ /* flag we returned happy here */
+ xorl %eax, %eax
+ ret
+
+ .size real_to_prot, .-real_to_prot
+
+/* ------------------------------------------------------------------------ */
+
+/* Note: This routine should not change any other standard registers than eax */
+
+ .section .boot.text.prot_to_real, "ax"
+ .globl prot_to_real
+ .type prot_to_real, @function
+ .extern boot_stack
+ .code32
+
+prot_to_real:
+ /* save the protected mode stack */
+ movl %esp, %eax
+ movl %eax, protstack
+
+ /* prepare the real mode stack */
+ /* - address to call to the top of this stack */
+ movl (%esp), %eax
+ movl %eax, boot_stack - 4
+
+ /* - the stack itself */
+ movl $boot_stack - 4, %eax
+ movl %eax, %esp
+ movl %eax, %ebp
+
+ /* prepare segments limits to 16 bit */
+ movw $__REAL_DS, %ax
+ movw %ax, %ds
+ movw %ax, %es
+ movw %ax, %fs
+ movw %ax, %gs
+ movw %ax, %ss
+
+ /* at last, also limit the code segment to 16 bit */
+ ljmp $__REAL_CS, $return_to_realmode
+
+/* ----------------------------------------------------------------------- */
+
+ .section .boot.text.return_to_realmode, "ax"
+return_to_realmode:
+ .code16
+
+ /* disable protected mode */
+ movl %cr0, %eax
+ andl $(~0x00000001), %eax
+ movl %eax, %cr0
+
+ /*
+ * all the protected mode settings are still cached in the CPU.
+ * Refresh them by re-loading all registers in realmode
+ * Start with the CS, continue with the data registers
+ */
+ ljmp $0, $enter_realmode
+
+enter_realmode:
+ xorl %eax, %eax
+ movw %ax, %ds
+ movw %ax, %es
+ movw %ax, %fs
+ movw %ax, %gs
+ movw %ax, %ss
+ /*
+ * back in plain real mode now, we can play again with the BIOS
+ */
+
+ /* restore interrupts */
+ sti
+
+ /* return on realmode stack! */
+ DATA32 ret
+
+ .size prot_to_real, .-prot_to_real
+
+#endif
Index: u-boot-2.0.0-rc10/arch/x86/lib/memory16.S
===================================================================
--- /dev/null
+++ u-boot-2.0.0-rc10/arch/x86/lib/memory16.S
@@ -0,0 +1,73 @@
+/*
+ * Copyright (C) 2009 Juergen Beisert, Pengutronix
+ *
+ * This code was inspired by the GRUB2 project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ *
+ */
+
+/**
+ * @file
+ * @brief Query the memory layout information from the BIOS
+ *
+ * Note: This function is running in flat and real mode. Due to some
+ * other restrictions it must running from an address space below 0x10000
+ */
+
+/**
+ * @fn unsigned short bios_get_memsize(void)
+ * @brief Does a BIOS call "INT 15H, AH=88H" to get extended memory size
+ * @return Extended memory size in KB
+ *
+ * @note This call is limited to 64 MiB. So, if the system provides more than
+ * 64 MiB of memory, still 64 MiB are reported.
+ *
+ */
+
+#ifndef DOXYGEN_SHOULD_SKIP_THIS
+
+ .section .boot.text.bios_get_memsize, "ax"
+ .code32
+ .globl bios_get_memsize
+ .type bios_get_memsize, @function
+
+ .extern prot_to_real
+
+bios_get_memsize:
+
+ pushl %ebp
+
+ call prot_to_real /* enter real mode */
+ .code16
+
+ movb $0x88, %ah
+ int $0x15
+
+ movw %ax, %dx
+
+ DATA32 call real_to_prot
+
+ .code32
+
+ movw %dx, %ax
+
+ popl %ebp
+ ret
+
+ .size bios_get_memsize, .-bios_get_memsize
+
+#endif
--
_______________________________________________
u-boot-v2 mailing list
u-boot-v2@xxxxxxxxxxxxxxxxxxx
http://lists.infradead.org/mailman/listinfo/u-boot-v2
