u-boot-brain/arch/x86/lib/board.c
Graeme Russ 9e6c572ff0 x86: Use fs for global data
Use the base address of the 'F' segment as a pointer to the global data
structure. By adding the linear address (i.e. the 'D' segment address) as
the first word of the global data structure, the address of the global data
relative to the 'D' segment can be found simply, for example, by:

	fs movl 0, %eax

This makes the gd 'pointer' writable prior to relocation (by reloading the
Global Desctriptor Table) which brings x86 into line with all other arches

NOTE: Writing to the gd 'pointer' is expensive (but we only do it
twice) but using it to access global data members (read and write) is
still fairly cheap

--
Changes for v2:
 - Rebased against changes made to patch #3
 - Removed extra indent
 - Tweaked commit message
2012-01-04 22:17:24 +11:00

517 lines
12 KiB
C

/*
* (C) Copyright 2008-2011
* Graeme Russ, <graeme.russ@gmail.com>
*
* (C) Copyright 2002
* Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
*
* (C) Copyright 2002
* Wolfgang Denk, DENX Software Engineering, <wd@denx.de>
*
* (C) Copyright 2002
* Sysgo Real-Time Solutions, GmbH <www.elinos.com>
* Marius Groeger <mgroeger@sysgo.de>
*
* 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
*/
#include <common.h>
#include <watchdog.h>
#include <command.h>
#include <stdio_dev.h>
#include <version.h>
#include <malloc.h>
#include <net.h>
#include <ide.h>
#include <serial.h>
#include <asm/u-boot-x86.h>
#include <elf.h>
#include <asm/processor.h>
#ifdef CONFIG_BITBANGMII
#include <miiphy.h>
#endif
/************************************************************************
* Init Utilities *
************************************************************************
* Some of this code should be moved into the core functions,
* or dropped completely,
* but let's get it working (again) first...
*/
static int init_baudrate(void)
{
gd->baudrate = getenv_ulong("baudrate", 10, CONFIG_BAUDRATE);
return 0;
}
static int display_banner(void)
{
printf("\n\n%s\n\n", version_string);
return 0;
}
static int display_dram_config(void)
{
int i;
puts("DRAM Configuration:\n");
for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) {
printf("Bank #%d: %08lx ", i, gd->bd->bi_dram[i].start);
print_size(gd->bd->bi_dram[i].size, "\n");
}
return 0;
}
#ifndef CONFIG_SYS_NO_FLASH
static void display_flash_config(ulong size)
{
puts("Flash: ");
print_size(size, "\n");
}
#endif
/*
* Breath some life into the board...
*
* Initialize an SMC for serial comms, and carry out some hardware
* tests.
*
* The first part of initialization is running from Flash memory;
* its main purpose is to initialize the RAM so that we
* can relocate the monitor code to RAM.
*/
/*
* All attempts to come up with a "common" initialization sequence
* that works for all boards and architectures failed: some of the
* requirements are just _too_ different. To get rid of the resulting
* mess of board dependend #ifdef'ed code we now make the whole
* initialization sequence configurable to the user.
*
* The requirements for any new initalization function is simple: it
* receives a pointer to the "global data" structure as it's only
* argument, and returns an integer return code, where 0 means
* "continue" and != 0 means "fatal error, hang the system".
*/
typedef int (init_fnc_t) (void);
static int calculate_relocation_address(void);
static int copy_uboot_to_ram(void);
static int clear_bss(void);
static int do_elf_reloc_fixups(void);
static int copy_gd_to_ram(void);
init_fnc_t *init_sequence_f[] = {
cpu_init_f,
board_early_init_f,
env_init,
init_baudrate,
serial_init,
console_init_f,
dram_init_f,
calculate_relocation_address,
copy_uboot_to_ram,
clear_bss,
do_elf_reloc_fixups,
NULL,
};
init_fnc_t *init_sequence_r[] = {
copy_gd_to_ram,
cpu_init_r, /* basic cpu dependent setup */
board_early_init_r, /* basic board dependent setup */
dram_init, /* configure available RAM banks */
interrupt_init, /* set up exceptions */
timer_init,
display_banner,
display_dram_config,
NULL,
};
static int calculate_relocation_address(void)
{
ulong text_start = (ulong)&__text_start;
ulong bss_end = (ulong)&__bss_end;
ulong dest_addr;
/*
* NOTE: All destination address are rounded down to 16-byte
* boundary to satisfy various worst-case alignment
* requirements
*/
/* Global Data is at top of available memory */
dest_addr = gd->ram_size;
dest_addr -= GENERATED_GBL_DATA_SIZE;
dest_addr &= ~15;
gd->new_gd_addr = dest_addr;
/* GDT is below Global Data */
dest_addr -= X86_GDT_SIZE;
dest_addr &= ~15;
gd->gdt_addr = dest_addr;
/* Stack is below GDT */
gd->start_addr_sp = dest_addr;
/* U-Boot is below the stack */
dest_addr -= CONFIG_SYS_STACK_SIZE;
dest_addr -= (bss_end - text_start);
dest_addr &= ~15;
gd->relocaddr = dest_addr;
gd->reloc_off = (dest_addr - text_start);
return 0;
}
static int copy_uboot_to_ram(void)
{
size_t len = (size_t)&__data_end - (size_t)&__text_start;
memcpy((void *)gd->relocaddr, (void *)&__text_start, len);
return 0;
}
static int clear_bss(void)
{
ulong dst_addr = (ulong)&__bss_start + gd->reloc_off;
size_t len = (size_t)&__bss_end - (size_t)&__bss_start;
memset((void *)dst_addr, 0x00, len);
return 0;
}
static int do_elf_reloc_fixups(void)
{
Elf32_Rel *re_src = (Elf32_Rel *)(&__rel_dyn_start);
Elf32_Rel *re_end = (Elf32_Rel *)(&__rel_dyn_end);
Elf32_Addr *offset_ptr_rom;
Elf32_Addr *offset_ptr_ram;
/* The size of the region of u-boot that runs out of RAM. */
uintptr_t size = (uintptr_t)&__bss_end - (uintptr_t)&__text_start;
do {
/* Get the location from the relocation entry */
offset_ptr_rom = (Elf32_Addr *)re_src->r_offset;
/* Check that the location of the relocation is in .text */
if (offset_ptr_rom >= (Elf32_Addr *)CONFIG_SYS_TEXT_BASE) {
/* Switch to the in-RAM version */
offset_ptr_ram = (Elf32_Addr *)((ulong)offset_ptr_rom +
gd->reloc_off);
/* Check that the target points into .text */
if (*offset_ptr_ram >= CONFIG_SYS_TEXT_BASE &&
*offset_ptr_ram <
(CONFIG_SYS_TEXT_BASE + size)) {
*offset_ptr_ram += gd->reloc_off;
}
}
} while (re_src++ < re_end);
return 0;
}
/* Load U-Boot into RAM, initialize BSS, perform relocation adjustments */
void board_init_f(ulong boot_flags)
{
init_fnc_t **init_fnc_ptr;
gd->flags = boot_flags;
for (init_fnc_ptr = init_sequence_f; *init_fnc_ptr; ++init_fnc_ptr) {
if ((*init_fnc_ptr)() != 0)
hang();
}
gd->flags |= GD_FLG_RELOC;
/*
* SDRAM is now initialised, U-Boot has been copied into SDRAM,
* the BSS has been cleared etc. The final stack can now be setup
* in SDRAM. Code execution will continue (momentarily) in Flash,
* but with the stack in SDRAM and Global Data in temporary memory
* (CPU cache)
*/
board_init_f_r_trampoline(gd->start_addr_sp);
/* NOTREACHED - board_init_f_r_trampoline() does not return */
while (1)
;
}
void board_init_f_r(void)
{
/*
* Transfer execution from Flash to RAM by calculating the address
* of the in-RAM copy of board_init_r() and calling it
*/
(board_init_r + gd->reloc_off)(gd, gd->relocaddr);
/* NOTREACHED - board_init_r() does not return */
while (1)
;
}
static int copy_gd_to_ram(void)
{
gd_t *ram_gd;
/*
* Global data is still in temporary memory (the CPU cache).
* calculate_relocation_address() has set gd->new_gd_addr to
* where the global data lives in RAM but getting it there
* safely is a bit tricky due to the 'F-Segment Hack' that
* we need to use for x86
*/
ram_gd = (gd_t *)gd->new_gd_addr;
memcpy((void *)ram_gd, gd, sizeof(gd_t));
/*
* Reload the Global Descriptor Table so FS points to the
* in-RAM copy of Global Data (calculate_relocation_address()
* has already calculated the in-RAM location of the GDT)
*/
ram_gd->gd_addr = (ulong)ram_gd;
init_gd(ram_gd, (u64 *)gd->gdt_addr);
return 0;
}
void board_init_r(gd_t *id, ulong dest_addr)
{
#if defined(CONFIG_CMD_NET)
char *s;
#endif
#ifndef CONFIG_SYS_NO_FLASH
ulong size;
#endif
static bd_t bd_data;
init_fnc_t **init_fnc_ptr;
show_boot_progress(0x21);
/* compiler optimization barrier needed for GCC >= 3.4 */
__asm__ __volatile__("" : : : "memory");
gd->bd = &bd_data;
memset(gd->bd, 0, sizeof(bd_t));
show_boot_progress(0x22);
gd->baudrate = CONFIG_BAUDRATE;
mem_malloc_init((((ulong)dest_addr - CONFIG_SYS_MALLOC_LEN)+3)&~3,
CONFIG_SYS_MALLOC_LEN);
for (init_fnc_ptr = init_sequence_r; *init_fnc_ptr; ++init_fnc_ptr) {
if ((*init_fnc_ptr)() != 0)
hang();
}
show_boot_progress(0x23);
#ifdef CONFIG_SERIAL_MULTI
serial_initialize();
#endif
#ifndef CONFIG_SYS_NO_FLASH
/* configure available FLASH banks */
size = flash_init();
display_flash_config(size);
show_boot_progress(0x24);
#endif
show_boot_progress(0x25);
/* initialize environment */
env_relocate();
show_boot_progress(0x26);
#ifdef CONFIG_CMD_NET
/* IP Address */
bd_data.bi_ip_addr = getenv_IPaddr("ipaddr");
#endif
#if defined(CONFIG_PCI)
/*
* Do pci configuration
*/
pci_init();
#endif
show_boot_progress(0x27);
stdio_init();
jumptable_init();
/* Initialize the console (after the relocation and devices init) */
console_init_r();
#ifdef CONFIG_MISC_INIT_R
/* miscellaneous platform dependent initialisations */
misc_init_r();
#endif
#if defined(CONFIG_CMD_PCMCIA) && !defined(CONFIG_CMD_IDE)
WATCHDOG_RESET();
puts("PCMCIA:");
pcmcia_init();
#endif
#if defined(CONFIG_CMD_KGDB)
WATCHDOG_RESET();
puts("KGDB: ");
kgdb_init();
#endif
/* enable exceptions */
enable_interrupts();
show_boot_progress(0x28);
#ifdef CONFIG_STATUS_LED
status_led_set(STATUS_LED_BOOT, STATUS_LED_BLINKING);
#endif
udelay(20);
/* Initialize from environment */
load_addr = getenv_ulong("loadaddr", 16, load_addr);
#if defined(CONFIG_CMD_NET)
s = getenv("bootfile");
if (s != NULL)
copy_filename(BootFile, s, sizeof(BootFile));
#endif
WATCHDOG_RESET();
#if defined(CONFIG_CMD_IDE)
WATCHDOG_RESET();
puts("IDE: ");
ide_init();
#endif
#if defined(CONFIG_CMD_SCSI)
WATCHDOG_RESET();
puts("SCSI: ");
scsi_init();
#endif
#if defined(CONFIG_CMD_DOC)
WATCHDOG_RESET();
puts("DOC: ");
doc_init();
#endif
#ifdef CONFIG_BITBANGMII
bb_miiphy_init();
#endif
#if defined(CONFIG_CMD_NET)
WATCHDOG_RESET();
puts("Net: ");
eth_initialize(gd->bd);
#endif
#if (defined(CONFIG_CMD_NET)) && (0)
WATCHDOG_RESET();
# ifdef DEBUG
puts("Reset Ethernet PHY\n");
# endif
reset_phy();
#endif
#ifdef CONFIG_LAST_STAGE_INIT
WATCHDOG_RESET();
/*
* Some parts can be only initialized if all others (like
* Interrupts) are up and running (i.e. the PC-style ISA
* keyboard).
*/
last_stage_init();
#endif
#ifdef CONFIG_POST
post_run(NULL, POST_RAM | post_bootmode_get(0));
#endif
show_boot_progress(0x29);
/* main_loop() can return to retry autoboot, if so just run it again. */
for (;;)
main_loop();
/* NOTREACHED - no way out of command loop except booting */
}
void hang(void)
{
puts("### ERROR ### Please RESET the board ###\n");
for (;;)
;
}
unsigned long do_go_exec(ulong (*entry)(int, char * const []),
int argc, char * const argv[])
{
unsigned long ret = 0;
char **argv_tmp;
/*
* x86 does not use a dedicated register to pass the pointer to
* the global_data, so it is instead passed as argv[-1]. By using
* argv[-1], the called 'Application' can use the contents of
* argv natively. However, to safely use argv[-1] a new copy of
* argv is needed with the extra element
*/
argv_tmp = malloc(sizeof(char *) * (argc + 1));
if (argv_tmp) {
argv_tmp[0] = (char *)gd;
memcpy(&argv_tmp[1], argv, (size_t)(sizeof(char *) * argc));
ret = (entry) (argc, &argv_tmp[1]);
free(argv_tmp);
}
return ret;
}
void setup_pcat_compatibility(void)
__attribute__((weak, alias("__setup_pcat_compatibility")));
void __setup_pcat_compatibility(void)
{
}