/* * (C) Copyright 2008-2011 * Graeme Russ, * * (C) Copyright 2002 * Daniel Engström, Omicron Ceti AB, * * (C) Copyright 2002 * Wolfgang Denk, DENX Software Engineering, * * (C) Copyright 2002 * Sysgo Real-Time Solutions, GmbH * Marius Groeger * * 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 #include #include #include #include #include #include #include #include #include /* * Breath some life into the board... * * Getting the board up and running is a three-stage process: * 1) Execute from Flash, SDRAM Uninitialised * At this point, there is a limited amount of non-SDRAM memory * (typically the CPU cache, but can also be SRAM or even a buffer of * of some peripheral). This limited memory is used to hold: * - The initial copy of the Global Data Structure * - A temporary stack * - A temporary x86 Global Descriptor Table * - The pre-console buffer (if enabled) * * The following is performed during this phase of execution: * - Core low-level CPU initialisation * - Console initialisation * - SDRAM initialisation * * 2) Execute from Flash, SDRAM Initialised * At this point we copy Global Data from the initial non-SDRAM * memory and set up the permanent stack in SDRAM. The CPU cache is no * longer being used as temporary memory, so we can now fully enable * it. * * The following is performed during this phase of execution: * - Create final stack in SDRAM * - Copy Global Data from temporary memory to SDRAM * - Enabling of CPU cache(s), * - Copying of U-Boot code and data from Flash to RAM * - Clearing of the BSS * - ELF relocation adjustments * * 3) Execute from SDRAM * The following is performed during this phase of execution: * - All remaining initialisation */ /* * The requirements for any new initalization function is simple: it is * a function with no parameters which returns an integer return code, * where 0 means "continue" and != 0 means "fatal error, hang the system" */ typedef int (init_fnc_t) (void); /* * init_sequence_f is the list of init functions which are run when U-Boot * is executing from Flash with a limited 'C' environment. The following * limitations must be considered when implementing an '_f' function: * - 'static' variables are read-only * - Global Data (gd->xxx) is read/write * - Stack space is limited * * The '_f' sequence must, as a minimum, initialise SDRAM. It _should_ * also initialise the console (to provide early debug output) */ init_fnc_t *init_sequence_f[] = { cpu_init_f, board_early_init_f, #ifdef CONFIG_OF_CONTROL find_fdt, fdtdec_check_fdt, #endif env_init, init_baudrate_f, serial_init, console_init_f, #ifdef CONFIG_OF_CONTROL prepare_fdt, #endif dram_init_f, calculate_relocation_address, NULL, }; /* * init_sequence_f_r is the list of init functions which are run when * U-Boot is executing from Flash with a semi-limited 'C' environment. * The following limitations must be considered when implementing an * '_f_r' function: * - 'static' variables are read-only * - Global Data (gd->xxx) is read/write * * The '_f_r' sequence must, as a minimum, copy U-Boot to RAM (if * supported). It _should_, if possible, copy global data to RAM and * initialise the CPU caches (to speed up the relocation process) */ init_fnc_t *init_sequence_f_r[] = { init_cache_f_r, copy_uboot_to_ram, copy_fdt_to_ram, clear_bss, do_elf_reloc_fixups, NULL, }; /* * init_sequence_r is the list of init functions which are run when U-Boot * is executing from RAM with a full 'C' environment. There are no longer * any limitations which must be considered when implementing an '_r' * function, (i.e.'static' variables are read/write) * * If not already done, the '_r' sequence must copy global data to RAM and * (should) initialise the CPU caches. */ init_fnc_t *init_sequence_r[] = { set_reloc_flag_r, init_bd_struct_r, mem_malloc_init_r, cpu_init_r, board_early_init_r, dram_init, interrupt_init, timer_init, display_banner, display_dram_config, serial_initialize_r, #ifndef CONFIG_SYS_NO_FLASH flash_init_r, #endif #ifdef CONFIG_PCI pci_init_r, #endif #ifdef CONFIG_SPI init_func_spi, #endif env_relocate_r, stdio_init, jumptable_init_r, console_init_r, #ifdef CONFIG_MISC_INIT_R misc_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_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 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(); } } void board_init_f(ulong boot_flags) { gd->fdt_blob = gd->new_fdt = NULL; gd->flags = boot_flags; do_init_loop(init_sequence_f); /* * SDRAM and console are now initialised. The final stack can now * be setup in SDRAM. Code execution will continue 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) { do_init_loop(init_sequence_f_r); /* * U-Boot has been copied into SDRAM, the BSS has been cleared etc. * 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) ; } void board_init_r(gd_t *id, ulong dest_addr) { 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 */ }