[U-Boot] Where I'm going with x86 board.c
Simon Glass
sjg at chromium.org
Thu Dec 22 07:44:47 CET 2011
Hi Graeme,
On Tue, Dec 20, 2011 at 4:06 AM, Graeme Russ <graeme.russ at gmail.com> wrote:
> With Simon's work on generic relocation support, I thought I would throw in
> what I am planning for arch/x86/lib/board.c
>
> Now this is not a patch, it is a work-in-progress complete version of the
> file (compiles, will test soon) - If feedback is positive, I'll add this to
> an upcoming patch set
Looks good to me+++
>
> Notice the amount of wrapping around void functions - If all other arch's
> follow this lead, most of this wrapping can be removed by changing the
> function signatures.
>
> Lines 428 - 585 are effectively the generic init sequence - The rest is
> wrappers, init sequence arrays, or fluff that should be moved
>
> I noticed something along the way - gd is no longer special... let me
> explain...
>
> Some arch's use a dedicated register for the gd pointer - This allows the
> pointer to be written to prior to relocation. For x86, the gd pointer is
> simply passed around as a function parameter early - If the init_sequence_f
> functions accepted a gd pointer as a parameter, there would be no need for
> it to be global prior to relocation and therefore no need to allocate a
> permanent register for it - Of course do_init_loop() would no longer be
> generic for both pre and post relocation. This does mess with the
> stand-alone API, but as discussed before, stand alone applications should
> not be accessing gd anyway, so there should be no API to break ;)
Actually as it happens I did a bit of an experiment with this some
weeks ago and my original board stuff had gd as a parameter for the
pre-reloc functions (some with stubs to other ones like
console_init_f()). On ARM it really doesn't make a lot of sense to use
a global variable instead of a parameter. I decided that it was a bit
much to bite off in one go :-) Partly that was because IMO gd really
only makes sense prior to relocation - for the post-relocation init
calls they don't have a lot of need for gd.
So it has my vote. Once I get somewhere on the reboard series I will
post my common/board.c. As I may have mentioned I have elected so far
to leave the initcall list and local functions in
arch/xxx/lib/board.c.
Would be good to get all this moving.
Regards,
Simon
>
> And on that note, the following comment is well and truly wrong:
>
> * 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".
>
> And finally, here 'tis:
>
> /*
> * (C) Copyright 2008-2011
> * Graeme Russ, <graeme.russ at gmail.com>
> *
> * (C) Copyright 2002
> * Daniel Engström, Omicron Ceti AB, <daniel at omicron.se>
> *
> * (C) Copyright 2002
> * Wolfgang Denk, DENX Software Engineering, <wd at denx.de>
> *
> * (C) Copyright 2002
> * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
> * Marius Groeger <mgroeger at 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>
>
> #ifdef CONFIG_BITBANGMII
> #include <miiphy.h>
> #endif
>
> /*
> * Pointer to initial global data area
> *
> * Here we initialize it.
> */
> #undef XTRN_DECLARE_GLOBAL_DATA_PTR
> #define XTRN_DECLARE_GLOBAL_DATA_PTR /* empty = allocate here */
> DECLARE_GLOBAL_DATA_PTR = (gd_t *) (CONFIG_SYS_INIT_GD_ADDR);
>
> /************************************************************************
> * 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(gd_t *);
> static int copy_uboot_to_ram(gd_t *);
> static int clear_bss(gd_t *);
> static int do_elf_reloc_fixups(gd_t *);
>
> 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,
>
> NULL,
> };
>
> gd_t *gd;
> bd_t bd_data;
>
> static int init_bd_struct_r(void)
> {
> gd->bd = &bd_data;
> memset(gd->bd, 0, sizeof(bd_t));
>
> return 0;
> }
>
> static int mem_malloc_init_r(void)
> {
> mem_malloc_init(((gd->relocaddr - CONFIG_SYS_MALLOC_LEN)+3)&~3,
> CONFIG_SYS_MALLOC_LEN);
>
> return 0;
> }
>
> static int set_default_baudrate_r(void)
> {
> gd->baudrate = CONFIG_BAUDRATE;
> return 0;
> }
>
> #ifdef CONFIG_SERIAL_MULTI
> static int serial_initialize_r(void)
> {
> serial_initialize();
>
> return 0;
> }
> #endif
>
> #ifndef CONFIG_SYS_NO_FLASH
> static int flash_init_r(void)
> {
> ulong size;
>
> /* configure available FLASH banks */
> size = flash_init();
> display_flash_config(size);
> show_boot_progress(0x24);
>
> return 0;
> }
> #endif
>
> static int env_relocate_r(void)
> {
> /* initialize environment */
> env_relocate();
> show_boot_progress(0x26);
>
> return 0;
> }
>
> #ifdef CONFIG_CMD_NET
> static int init_ip_address_r(void)
> {
> /* IP Address */
> bd_data.bi_ip_addr = getenv_IPaddr("ipaddr");
>
> return 0;
> }
> #endif
>
> #ifdef CONFIG_PCI
> static int pci_init_r(void)
> {
> /*
> * Do pci configuration
> */
> pci_init();
>
> return 0;
> }
> #endif
>
> static int jumptable_init_r(void)
> {
> jumptable_init();
>
> return 0;
> }
>
> #if defined(CONFIG_CMD_PCMCIA) && !defined(CONFIG_CMD_IDE)
> static int pci_init_r(void)
> {
> puts("PCMCIA:");
> pcmcia_init();
>
> return 0;
> }
> #endif
>
> #if defined(CONFIG_CMD_KGDB)
> static int kgdb_init_r(void)
> {
> puts("KGDB: ");
> kgdb_init();
>
> return 0;
> }
> #endif
>
> static int enable_interrupts_r(void)
> {
> /* enable exceptions */
> enable_interrupts();
> show_boot_progress(0x28);
>
> return 0;
> }
>
> #ifdef CONFIG_STATUS_LED
> static int status_led_set_r(void)
> {
> status_led_set(STATUS_LED_BOOT, STATUS_LED_BLINKING);
> udelay(20);
>
> return 0;
> }
> #endif
>
> #if defined(CONFIG_CMD_NET)
> static int set_bootfile_r(void)
> {
> char *s;
>
> s = getenv("bootfile");
>
> if (s != NULL)
> copy_filename(BootFile, s, sizeof(BootFile));
>
> return 0;
> }
>
> static int eth_initialize_r(void)
> {
> puts("Net: ");
> eth_initialize(gd->bd);
>
> return 0;
> }
>
> #ifdef CONFIG_RESET_PHY_R
> static int reset_phy_r(void)
> {
> #ifdef DEBUG
> puts("Reset Ethernet PHY\n");
> #endif
> reset_phy();
>
> return 0;
> }
> #endif
>
> #endif
>
> static int set_load_addr_r(void)
> {
> /* Initialize from environment */
> load_addr = getenv_ulong("loadaddr", 16, load_addr);
>
> return 0;
> }
>
> #if defined(CONFIG_CMD_IDE)
> static int ide_init_r(void)
> {
> puts("IDE: ");
> ide_init();
>
> return 0;
> }
> #endif
>
> #if defined(CONFIG_CMD_SCSI)
> static int scsi_init_r(void)
> {
> puts("SCSI: ");
> scsi_init();
>
> return 0;
> }
> #endif
>
> #if defined(CONFIG_CMD_DOC)
> static int doc_init_r(void)
> {
> puts("DOC: ");
> doc_init();
>
> return 0;
> }
> #endif
>
> #ifdef CONFIG_BITBANGMII
> static int bb_miiphy_init_r(void)
> {
> bb_miiphy_init();
>
> return 0;
> }
> #endif
>
> #ifdef CONFIG_POST
> static int post_run_r(void)
> {
> post_run(NULL, POST_RAM | post_bootmode_get(0));
>
> return 0;
> }
> #endif
>
> init_fnc_t *init_sequence_r[] = {
> init_bd_struct_r,
> mem_malloc_init_r,
> set_default_baudrate_r,
> 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,
> #ifdef CONFIG_SERIAL_MULTI
> serial_initialize_r,
> #endif
> #ifndef CONFIG_SYS_NO_FLASH
> flash_init_r,
> #endif
> env_relocate_r,
> #ifdef CONFIG_CMD_NET
> init_ip_address_r,
> #endif
> #ifdef CONFIG_PCI
> pci_init_r,
> #endif
> stdio_init,
> jumptable_init_r,
> console_init_r,
> #ifdef CONFIG_MISC_INIT_R
> misc_init_r,
> #endif
> #if defined(CONFIG_CMD_PCMCIA) && !defined(CONFIG_CMD_IDE)
> pci_init_r,
> #endif
> #if defined(CONFIG_CMD_KGDB)
> kgdb_init_r,
> #endif
> enable_interrupts_r,
> #ifdef CONFIG_STATUS_LED
> status_led_set_r,
> #endif
> set_load_addr_r,
> #if defined(CONFIG_CMD_NET)
> set_bootfile_r,
> #endif
> #if defined(CONFIG_CMD_IDE)
> ide_init_r,
> #endif
> #if defined(CONFIG_CMD_SCSI)
> scsi_init_r,
> #endif
> #if defined(CONFIG_CMD_DOC)
> doc_init_r,
> #endif
> #ifdef CONFIG_BITBANGMII
> bb_miiphy_init_r,
> #endif
> #if defined(CONFIG_CMD_NET)
> eth_initialize_r,
> #ifdef CONFIG_RESET_PHY_R
> reset_phy_r,
> #endif
> #endif
> #ifdef CONFIG_LAST_STAGE_INIT
> last_stage_init,
> #endif
> NULL,
> };
>
> static int calculate_relocation_address(gd_t *id)
> {
> ulong text_start = (ulong)&__text_start;
> ulong bss_end = (ulong)&__bss_end;
> ulong dest_addr;
> ulong rel_offset;
>
> /* Calculate destination RAM Address and relocation offset */
> dest_addr = id->start_addr_sp;
> dest_addr -= CONFIG_SYS_STACK_SIZE;
> dest_addr -= (bss_end - text_start);
>
> /*
> * Round destination address down to 16-byte boundary to keep
> * IDT and GDT 16-byte aligned
> */
> dest_addr &= ~15;
>
> rel_offset = dest_addr - text_start;
>
> id->relocaddr = dest_addr;
> id->reloc_off = rel_offset;
>
> return 0;
> }
>
> static int copy_uboot_to_ram(gd_t *id)
> {
> size_t len = (size_t)&__data_end - (size_t)&__text_start;
>
> memcpy((void *)id->relocaddr, (void *)&__text_start, len);
>
> return 0;
> }
>
> static int clear_bss(gd_t *id)
> {
> ulong dst_addr = (ulong)&__bss_start + id->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(gd_t *id)
> {
> 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 +
> id->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 += id->reloc_off;
> }
> }
> } while (re_src++ < re_end);
>
> return 0;
> }
>
> static void do_init_loop(init_fnc_t **init_fnc_ptr)
> {
> for (; *init_fnc_ptr; ++init_fnc_ptr) {
> WATCHDOG_RESET();
> if ((*init_fnc_ptr)() != 0)
> hang();
> }
> }
>
> /* Load U-Boot into RAM, initialize BSS, perform relocation adjustments */
> void board_init_f(ulong boot_flags)
> {
> gd->flags = boot_flags;
>
> do_init_loop(init_sequence_f);
>
> /* SDRAM is now initialised setup a new stack in SDRAM */
> setup_sdram_environment(gd->ram_size, GENERATED_GBL_DATA_SIZE);
>
> /* NOTREACHED - relocate_code() does not return */
> while (1)
> ;
> }
>
> typedef void (board_init_r_t) (gd_t *, ulong);
>
> void relocate_code(ulong stack_ptr, gd_t *id, ulong reloc_addr)
> {
> board_init_r_t *board_init_r_func;
>
> /* We are running from flash, but the stack is now in SDRAM */
>
> /* gd is still in CAR - Copy it into SDRAM */
> memcpy(id, gd, sizeof(gd_t));
>
> id->start_addr_sp = stack_ptr;
>
> if (init_cache() != 0)
> hang();
>
> calculate_relocation_address(id);
> copy_uboot_to_ram(id);
> clear_bss(id);
> do_elf_reloc_fixups(id);
>
> board_init_r_func = board_init_r;
> board_init_r_func += id->reloc_off;
> board_init_r_func(id, id->relocaddr);
>
> /* NOTREACHED - relocate_code() does not return */
> while (1)
> ;
> }
>
> void board_init_r(gd_t *id, ulong dest_addr)
> {
> /* Global data pointer is now writable */
> gd = id;
>
> gd->flags |= GD_FLG_RELOC;
>
> /* compiler optimization barrier needed for GCC >= 3.4 */
> __asm__ __volatile__("" : : : "memory");
>
> do_init_loop(init_sequence_r);
>
> /* 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)
> {
> }
>
>
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