uboot代码解析1：根据目的找主线
2024-04-22 07:15:58
https://ke.qq.com/course/4032547?flowToken=1042705
为什么要解析uboot代码呢？当然是因为遇到棘手的问题啦。
目录
前言
一 uboot启动都干了什么
二 找方法
三 我的目的:解决ramdisk问题
main_loop
run_main_loop
数组init_sequence_r
void board_init_r(gd_t *new_gd, ulong dest_addr)
void board_init_f(ulong dummy)
crt0.S
全局变量gd_t *gd;
do_bootm_linux :linux内核的入口函数
结构体typedef struct bootm_headers
前言
先记住这几个东西
全局变量:gd
全局数组：init_sequence_r和static init_fnc_t init_sequence_f[]
函数：main_loop,
linux启动入口函数do_bootm_linux
结构体typedef struct bootm_headers ：要研究ramdisk，就得研究它，
它是我此次分析的重点和主线，这就是我的目的，解决ramdisk问题。
把复杂的事情简单化，就是功力。
一 uboot启动都干了什么
uboot启动以后，先初始化各种硬件，然后进入main_loop,等待用户的交互操作，bootdelay是uboot里的一个环境变量，里面存放着整数，存储秒数，将bootdelay秒时间，uboot未接收到交互信号，就进入linux内核，并结束自己的生命。
uboot根据bootcmd加载zImage和设备树，然后将设备树和bootargs传递给内核。然后内核根据设备树初始化外设，不同的设备树，决定了zImage使用在不同的设备上，例如同一款产品的不同系列，高配版和低配版。
二 找方法
分析代码，讲究方式方法。
第一确定找主线。
其次就是有目的。目的就是动力，不忘初心牢记使命，方得始终。
例如你想修改网卡的MAC地址，或者想修添加一个自定义的命令，也可以向在uboot设置仅通过网络网络启动内核，无论是什么，找到一个目的
三 我的目的:解决ramdisk问题
uboot的是一个大号的裸板程序，裸板程序的特点就是有一个死循环，那就是main_loop，
第一个函数
main_loop
这个函数主要就是和用户交互的，就是解析用户输入的命令，然后给出结果。
main_loop被run_main_loop调用
/* We come here after U-Boot is initialised and ready to process commands */
void main_loop(void)
{const char *s;bootstage_mark_name(BOOTSTAGE_ID_MAIN_LOOP, "main_loop");#ifndef CONFIG_SYS_GENERIC_BOARDputs("Warning: Your board does not use generic board. Please read\n");puts("doc/README.generic-board and take action. Boards not\n");puts("upgraded by the late 2014 may break or be removed.\n");
#endif#ifdef CONFIG_VERSION_VARIABLEsetenv("ver", version_string); /* set version variable */
#endif /* CONFIG_VERSION_VARIABLE */cli_init();run_preboot_environment_command();#if defined(CONFIG_UPDATE_TFTP)update_tftp(0UL, NULL, NULL);
#endif /* CONFIG_UPDATE_TFTP */s = bootdelay_process();if (cli_process_fdt(&s))cli_secure_boot_cmd(s);autoboot_command(s);cli_loop();
}
run_main_loop
这个函数很简单，就是调用的main_loop,sandbox_main_loop_init先不管。
static int run_main_loop(void)
{
#ifdef CONFIG_SANDBOXsandbox_main_loop_init();
#endif/* main_loop() can return to retry autoboot, if so just run it again */for (;;)main_loop();return 0;
}数组init_sequence_r
run_main_loop又被赋值给了数组init_sequence_r，先看下init_sequence_r的类型和定义，init_sequence_r 是一个函数指针数组，里面被赋值各种硬件的初始化函数，看看这个数组的真身，这个数组就是初始化函数列表，里面的函数被依次调用，最后调用run_main_loop。
typedef int (*init_fnc_t)(void);init_fnc_t init_sequence_r[]/** Over time we hope to remove these functions with code fragments and* stub funtcions, and instead call the relevant function directly.** We also hope to remove most of the driver-related init and do it if/when* the driver is later used.** TODO: perhaps reset the watchdog in the initcall function after each call?*/
init_fnc_t init_sequence_r[] = {initr_trace,initr_reloc,/* TODO: could x86/PPC have this also perhaps? */
#ifdef CONFIG_ARMinitr_caches,/* Note: For Freescale LS2 SoCs, new MMU table is created in DDR.* A temporary mapping of IFC high region is since removed,* so environmental variables in NOR flash is not availble* until board_init() is called below to remap IFC to high* region.*/
#endifinitr_reloc_global_data,
#if defined(CONFIG_SYS_INIT_RAM_LOCK) && defined(CONFIG_E500)initr_unlock_ram_in_cache,
#endifinitr_barrier,initr_malloc,initr_console_record,
#ifdef CONFIG_SYS_NONCACHED_MEMORYinitr_noncached,
#endifbootstage_relocate,
#ifdef CONFIG_DMinitr_dm,
#endifinitr_bootstage,
#if defined(CONFIG_ARM) || defined(CONFIG_NDS32)board_init, /* Setup chipselects */
#endif/** TODO: printing of the clock inforamtion of the board is now* implemented as part of bdinfo command. Currently only support for* davinci SOC's is added. Remove this check once all the board* implement this.*/
#ifdef CONFIG_CLOCKSset_cpu_clk_info, /* Setup clock information */
#endifstdio_init_tables,initr_serial,initr_announce,INIT_FUNC_WATCHDOG_RESET
#ifdef CONFIG_NEEDS_MANUAL_RELOCinitr_manual_reloc_cmdtable,
#endif
#if defined(CONFIG_PPC) || defined(CONFIG_M68K)initr_trap,
#endif
#ifdef CONFIG_ADDR_MAPinitr_addr_map,
#endif
#if defined(CONFIG_BOARD_EARLY_INIT_R)board_early_init_r,
#endifINIT_FUNC_WATCHDOG_RESET
#ifdef CONFIG_LOGBUFFERinitr_logbuffer,
#endif
#ifdef CONFIG_POSTinitr_post_backlog,
#endifINIT_FUNC_WATCHDOG_RESET
#ifdef CONFIG_SYS_DELAYED_ICACHEinitr_icache_enable,
#endif
#if defined(CONFIG_PCI) && defined(CONFIG_SYS_EARLY_PCI_INIT)/** Do early PCI configuration _before_ the flash gets initialised,* because PCU ressources are crucial for flash access on some boards.*/initr_pci,
#endif
#ifdef CONFIG_WINBOND_83C553initr_w83c553f,
#endif
#ifdef CONFIG_ARCH_EARLY_INIT_Rarch_early_init_r,
#endifpower_init_board,
#ifndef CONFIG_SYS_NO_FLASHinitr_flash,
#endifINIT_FUNC_WATCHDOG_RESET
#if defined(CONFIG_PPC) || defined(CONFIG_M68K) || defined(CONFIG_X86) || \defined(CONFIG_SPARC)/* initialize higher level parts of CPU like time base and timers */cpu_init_r,
#endif
#ifdef CONFIG_PPCinitr_spi,
#endif
#ifdef CONFIG_CMD_NANDinitr_nand,
#endif
#ifdef CONFIG_CMD_ONENANDinitr_onenand,
#endif
#ifdef CONFIG_GENERIC_MMCinitr_mmc,
#endif
#ifdef CONFIG_HAS_DATAFLASHinitr_dataflash,
#endifinitr_env,
#ifdef CONFIG_SYS_BOOTPARAMS_LENinitr_malloc_bootparams,
#endifINIT_FUNC_WATCHDOG_RESETinitr_secondary_cpu,
#if defined(CONFIG_ID_EEPROM) || defined(CONFIG_SYS_I2C_MAC_OFFSET)mac_read_from_eeprom,
#endifINIT_FUNC_WATCHDOG_RESET
#if defined(CONFIG_PCI) && !defined(CONFIG_SYS_EARLY_PCI_INIT)/** Do pci configuration*/initr_pci,
#endifstdio_add_devices,initr_jumptable,
#ifdef CONFIG_APIinitr_api,
#endifconsole_init_r, /* fully init console as a device */
#ifdef CONFIG_DISPLAY_BOARDINFO_LATEshow_board_info,
#endif
#ifdef CONFIG_ARCH_MISC_INITarch_misc_init, /* miscellaneous arch-dependent init */
#endif
#ifdef CONFIG_MISC_INIT_Rmisc_init_r, /* miscellaneous platform-dependent init */
#endifINIT_FUNC_WATCHDOG_RESET
#ifdef CONFIG_CMD_KGDBinitr_kgdb,
#endifinterrupt_init,
#if defined(CONFIG_ARM) || defined(CONFIG_AVR32)initr_enable_interrupts,
#endif
#if defined(CONFIG_MICROBLAZE) || defined(CONFIG_AVR32) || defined(CONFIG_M68K)timer_init, /* initialize timer */
#endif
#if defined(CONFIG_STATUS_LED)initr_status_led,
#endif/* PPC has a udelay(20) here dating from 2002. Why? */
#ifdef CONFIG_CMD_NETinitr_ethaddr,
#endif
#ifdef CONFIG_BOARD_LATE_INITboard_late_init,
#endif
#ifdef CONFIG_FSL_FASTBOOTinitr_fastboot_setup,
#endif
#if defined(CONFIG_CMD_AMBAPP)ambapp_init_reloc,
#if defined(CONFIG_SYS_AMBAPP_PRINT_ON_STARTUP)initr_ambapp_print,
#endif
#endif
#ifdef CONFIG_CMD_SCSIINIT_FUNC_WATCHDOG_RESETinitr_scsi,
#endif
#ifdef CONFIG_CMD_DOCINIT_FUNC_WATCHDOG_RESETinitr_doc,
#endif
#ifdef CONFIG_BITBANGMIIinitr_bbmii,
#endif
#ifdef CONFIG_CMD_NETINIT_FUNC_WATCHDOG_RESETinitr_net,
#endif
#ifdef CONFIG_POSTinitr_post,
#endif
#if defined(CONFIG_CMD_PCMCIA) && !defined(CONFIG_CMD_IDE)initr_pcmcia,
#endif
#if defined(CONFIG_CMD_IDE)initr_ide,
#endif
#ifdef CONFIG_LAST_STAGE_INITINIT_FUNC_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_CMD_BEDBUGINIT_FUNC_WATCHDOG_RESETinitr_bedbug,
#endif
#if defined(CONFIG_PRAM) || defined(CONFIG_LOGBUFFER)initr_mem,
#endif
#ifdef CONFIG_PS2KBDinitr_kbd,
#endif
#if defined(CONFIG_SPARC)prom_init,
#endif
#ifdef CONFIG_FSL_FASTBOOTinitr_check_fastboot,
#endifrun_main_loop,
}void board_init_r(gd_t *new_gd, ulong dest_addr)
init_sequence_r在函数board_init_r中被调用
void board_init_r(gd_t *new_gd, ulong dest_addr)
{
#ifdef CONFIG_NEEDS_MANUAL_RELOCint i;
#endif#ifdef CONFIG_AVR32mmu_init_r(dest_addr);
#endif#if !defined(CONFIG_X86) && !defined(CONFIG_ARM) && !defined(CONFIG_ARM64)gd = new_gd;
#endif#ifdef CONFIG_NEEDS_MANUAL_RELOCfor (i = 0; i < ARRAY_SIZE(init_sequence_r); i++)init_sequence_r[i] += gd->reloc_off;
#endifif (initcall_run_list(init_sequence_r))hang();/* NOTREACHED - run_main_loop() does not return */hang();
}
void board_init_f(ulong dummy)
board_init_r被board_init_f调用
void board_init_f(ulong dummy)
{/* setup AIPS and disable watchdog */arch_cpu_init();ccgr_init();/* iomux and setup of i2c */board_early_init_f();/* setup GP timer */timer_init();/* UART clocks enabled and gd valid - init serial console */preloader_console_init();/* DDR initialization */spl_dram_init();/* Clear the BSS. */memset(__bss_start, 0, __bss_end - __bss_start);/* load/boot image from boot device */board_init_r(NULL, 0);
}crt0.S
board_init_f在crt0.S被ENTRY(_main)调用，好了到头了。
ENTRY(_main)/** Set up initial C runtime environment and call board_init_f(0).*/#if defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_STACK)ldr sp, =(CONFIG_SPL_STACK)
#elseldr sp, =(CONFIG_SYS_INIT_SP_ADDR)
#endif
#if defined(CONFIG_CPU_V7M) /* v7M forbids using SP as BIC destination */mov r3, spbic r3, r3, #7mov sp, r3
#elsebic sp, sp, #7 /* 8-byte alignment for ABI compliance */
#endifmov r0, spbl board_init_f_alloc_reservemov sp, r0/* set up gd here, outside any C code */mov r9, r0bl board_init_f_init_reservemov r0, #0bl board_init_f全局变量gd_t *gd;
这些函数里还使用了一个全局变量gd，gd的类型如下所示
gd_t *gd;
研究uboot整体脉络，就是IXUS研究gd这个变量。
typedef struct global_data {bd_t *bd;unsigned long flags;unsigned int baudrate;unsigned long cpu_clk; /* CPU clock in Hz! */unsigned long bus_clk;/* We cannot bracket this with CONFIG_PCI due to mpc5xxx */unsigned long pci_clk;unsigned long mem_clk;
#if defined(CONFIG_LCD) || defined(CONFIG_VIDEO)unsigned long fb_base; /* Base address of framebuffer mem */
#endif
#if defined(CONFIG_POST) || defined(CONFIG_LOGBUFFER)unsigned long post_log_word; /* Record POST activities */unsigned long post_log_res; /* success of POST test */unsigned long post_init_f_time; /* When post_init_f started */
#endif
#ifdef CONFIG_BOARD_TYPESunsigned long board_type;
#endifunsigned long have_console; /* serial_init() was called */
#ifdef CONFIG_PRE_CONSOLE_BUFFERunsigned long precon_buf_idx; /* Pre-Console buffer index */
#endifunsigned long env_addr; /* Address of Environment struct */unsigned long env_valid; /* Checksum of Environment valid? */unsigned long ram_top; /* Top address of RAM used by U-Boot */unsigned long relocaddr; /* Start address of U-Boot in RAM */phys_size_t ram_size; /* RAM size */
#ifdef CONFIG_SYS_MEM_RESERVE_SECURE
#define MEM_RESERVE_SECURE_SECURED 0x1
#define MEM_RESERVE_SECURE_MAINTAINED 0x2
#define MEM_RESERVE_SECURE_ADDR_MASK (~0x3)/** Secure memory addr* This variable needs maintenance if the RAM base is not zero,* or if RAM splits into non-consecutive banks. It also has a* flag indicating the secure memory is marked as secure by MMU.* Flags used: 0x1 secured* 0x2 maintained*/phys_addr_t secure_ram;
#endifunsigned long mon_len; /* monitor len */unsigned long irq_sp; /* irq stack pointer */unsigned long start_addr_sp; /* start_addr_stackpointer */unsigned long reloc_off;struct global_data *new_gd; /* relocated global data */#ifdef CONFIG_DMstruct udevice *dm_root; /* Root instance for Driver Model */struct udevice *dm_root_f; /* Pre-relocation root instance */struct list_head uclass_root; /* Head of core tree */
#endif
#ifdef CONFIG_TIMERstruct udevice *timer; /* Timer instance for Driver Model */
#endifconst void *fdt_blob; /* Our device tree, NULL if none */void *new_fdt; /* Relocated FDT */unsigned long fdt_size; /* Space reserved for relocated FDT */struct jt_funcs *jt; /* jump table */char env_buf[32]; /* buffer for getenv() before reloc. */
#ifdef CONFIG_TRACEvoid *trace_buff; /* The trace buffer */
#endif
#if defined(CONFIG_SYS_I2C)int cur_i2c_bus; /* current used i2c bus */
#endif
#ifdef CONFIG_SYS_I2C_MXCvoid *srdata[10];
#endifunsigned long timebase_h;unsigned long timebase_l;
#ifdef CONFIG_SYS_MALLOC_F_LENunsigned long malloc_base; /* base address of early malloc() */unsigned long malloc_limit; /* limit address */unsigned long malloc_ptr; /* current address */
#endif
#ifdef CONFIG_PCIstruct pci_controller *hose; /* PCI hose for early use */phys_addr_t pci_ram_top; /* top of region accessible to PCI */
#endif
#ifdef CONFIG_PCI_BOOTDELAYint pcidelay_done;
#endifstruct udevice *cur_serial_dev; /* current serial device */struct arch_global_data arch; /* architecture-specific data */
#ifdef CONFIG_CONSOLE_RECORDstruct membuff console_out; /* console output */struct membuff console_in; /* console input */
#endif
#ifdef CONFIG_DM_VIDEOulong video_top; /* Top of video frame buffer area */ulong video_bottom; /* Bottom of video frame buffer area */
#endif
}do_bootm_linux :linux内核的入口函数
一切事物终将走向灭亡，但也会迎来心生，uboot死亡的时候，就是内核出生的地方。
/* Main Entry point for arm bootm implementation** Modeled after the powerpc implementation* DIFFERENCE: Instead of calling prep and go at the end* they are called if subcommand is equal 0.*/
int do_bootm_linux(int flag, int argc, char * const argv[],bootm_headers_t *images)
{/* No need for those on ARM */if (flag & BOOTM_STATE_OS_BD_T || flag & BOOTM_STATE_OS_CMDLINE)return -1;if (flag & BOOTM_STATE_OS_PREP) {boot_prep_linux(images);return 0;}if (flag & (BOOTM_STATE_OS_GO | BOOTM_STATE_OS_FAKE_GO)) {boot_jump_linux(images, flag);return 0;}boot_prep_linux(images);boot_jump_linux(images, flag);return 0;
}结构体typedef struct bootm_headers
typedef struct bootm_headers {/** Legacy os image header, if it is a multi component image* then boot_get_ramdisk() and get_fdt() will attempt to get* data from second and third component accordingly.*/image_header_t *legacy_hdr_os; /* image header pointer */image_header_t legacy_hdr_os_copy; /* header copy */ulong legacy_hdr_valid;#if defined(CONFIG_FIT)const char *fit_uname_cfg; /* configuration node unit name */void *fit_hdr_os; /* os FIT image header */const char *fit_uname_os; /* os subimage node unit name */int fit_noffset_os; /* os subimage node offset */void *fit_hdr_rd; /* init ramdisk FIT image header */const char *fit_uname_rd; /* init ramdisk subimage node unit name */int fit_noffset_rd; /* init ramdisk subimage node offset */void *fit_hdr_fdt; /* FDT blob FIT image header */const char *fit_uname_fdt; /* FDT blob subimage node unit name */int fit_noffset_fdt;/* FDT blob subimage node offset */void *fit_hdr_setup; /* x86 setup FIT image header */const char *fit_uname_setup; /* x86 setup subimage node name */int fit_noffset_setup;/* x86 setup subimage node offset */
#endif#ifndef USE_HOSTCCimage_info_t os; /* os image info */ulong ep; /* entry point of OS */ulong rd_start, rd_end;/* ramdisk start/end */char *ft_addr; /* flat dev tree address */ulong ft_len; /* length of flat device tree */ulong initrd_start;ulong initrd_end;ulong cmdline_start;ulong cmdline_end;bd_t *kbd;
#endifint verify; /* getenv("verify")[0] != 'n' */#define BOOTM_STATE_START (0x00000001)
#define BOOTM_STATE_FINDOS (0x00000002)
#define BOOTM_STATE_FINDOTHER (0x00000004)
#define BOOTM_STATE_LOADOS (0x00000008)
#define BOOTM_STATE_RAMDISK (0x00000010)
#define BOOTM_STATE_FDT (0x00000020)
#define BOOTM_STATE_OS_CMDLINE (0x00000040)
#define BOOTM_STATE_OS_BD_T (0x00000080)
#define BOOTM_STATE_OS_PREP (0x00000100)
#define BOOTM_STATE_OS_FAKE_GO (0x00000200) /* 'Almost' run the OS */
#define BOOTM_STATE_OS_GO (0x00000400)int state;#ifdef CONFIG_LMBstruct lmb lmb; /* for memory mgmt */
#endif
}static init_fnc_t init_sequence_f[]
static init_fnc_t init_sequence_f[] = {
#ifdef CONFIG_SANDBOXsetup_ram_buf,
#endifsetup_mon_len,
#ifdef CONFIG_OF_CONTROLfdtdec_setup,
#endif
#ifdef CONFIG_TRACEtrace_early_init,
#endifinitf_malloc,initf_console_record,
#if defined(CONFIG_MPC85xx) || defined(CONFIG_MPC86xx)/* TODO: can this go into arch_cpu_init()? */probecpu,
#endif
#if defined(CONFIG_X86) && defined(CONFIG_HAVE_FSP)x86_fsp_init,
#endifarch_cpu_init, /* basic arch cpu dependent setup */initf_dm,arch_cpu_init_dm,mark_bootstage, /* need timer, go after init dm */
#if defined(CONFIG_BOARD_EARLY_INIT_F)board_early_init_f,
#endif/* TODO: can any of this go into arch_cpu_init()? */
#if defined(CONFIG_PPC) && !defined(CONFIG_8xx_CPUCLK_DEFAULT)get_clocks, /* get CPU and bus clocks (etc.) */
#if defined(CONFIG_TQM8xxL) && !defined(CONFIG_TQM866M) \&& !defined(CONFIG_TQM885D)adjust_sdram_tbs_8xx,
#endif/* TODO: can we rename this to timer_init()? */init_timebase,
#endif
#if defined(CONFIG_ARM) || defined(CONFIG_MIPS) || \defined(CONFIG_BLACKFIN) || defined(CONFIG_NDS32) || \defined(CONFIG_SPARC)timer_init, /* initialize timer */
#endif
#ifdef CONFIG_SYS_ALLOC_DPRAM
#if !defined(CONFIG_CPM2)dpram_init,
#endif
#endif
#if defined(CONFIG_BOARD_POSTCLK_INIT)board_postclk_init,
#endif
#if defined(CONFIG_SYS_FSL_CLK) || defined(CONFIG_M68K)get_clocks,
#endifenv_init, /* initialize environment */
#if defined(CONFIG_8xx_CPUCLK_DEFAULT)/* get CPU and bus clocks according to the environment variable */get_clocks_866,/* adjust sdram refresh rate according to the new clock */sdram_adjust_866,init_timebase,
#endifinit_baud_rate, /* initialze baudrate settings */serial_init, /* serial communications setup */console_init_f, /* stage 1 init of console */
#ifdef CONFIG_SANDBOXsandbox_early_getopt_check,
#endif
#ifdef CONFIG_OF_CONTROLfdtdec_prepare_fdt,
#endifdisplay_options, /* say that we are here */display_text_info, /* show debugging info if required */
#if defined(CONFIG_MPC8260)prt_8260_rsr,prt_8260_clks,
#endif /* CONFIG_MPC8260 */
#if defined(CONFIG_MPC83xx)prt_83xx_rsr,
#endif
#if defined(CONFIG_PPC) || defined(CONFIG_M68K)checkcpu,
#endifprint_cpuinfo, /* display cpu info (and speed) */
#if defined(CONFIG_MPC5xxx)prt_mpc5xxx_clks,
#endif /* CONFIG_MPC5xxx */
#if defined(CONFIG_DISPLAY_BOARDINFO)show_board_info,
#endifINIT_FUNC_WATCHDOG_INIT
#if defined(CONFIG_MISC_INIT_F)misc_init_f,
#endifINIT_FUNC_WATCHDOG_RESET
#if defined(CONFIG_HARD_I2C) || defined(CONFIG_SYS_I2C)init_func_i2c,
#endif
#if defined(CONFIG_HARD_SPI)init_func_spi,
#endifannounce_dram_init,/* TODO: unify all these dram functions? */
#if defined(CONFIG_ARM) || defined(CONFIG_X86) || defined(CONFIG_NDS32) || \defined(CONFIG_MICROBLAZE) || defined(CONFIG_AVR32)dram_init, /* configure available RAM banks */
#endif
#if defined(CONFIG_MIPS) || defined(CONFIG_PPC) || defined(CONFIG_M68K)init_func_ram,
#endif
#ifdef CONFIG_POSTpost_init_f,
#endifINIT_FUNC_WATCHDOG_RESET
#if defined(CONFIG_SYS_DRAM_TEST)testdram,
#endif /* CONFIG_SYS_DRAM_TEST */INIT_FUNC_WATCHDOG_RESET#ifdef CONFIG_POSTinit_post,
#endifINIT_FUNC_WATCHDOG_RESET/** Now that we have DRAM mapped and working, we can* relocate the code and continue running from DRAM.** Reserve memory at end of RAM for (top down in that order):* - area that won't get touched by U-Boot and Linux (optional)* - kernel log buffer* - protected RAM* - LCD framebuffer* - monitor code* - board info struct*/setup_dest_addr,
#if defined(CONFIG_BLACKFIN)/* Blackfin u-boot monitor should be on top of the ram */reserve_uboot,
#endif
#if defined(CONFIG_SPARC)reserve_prom,
#endif
#if defined(CONFIG_LOGBUFFER) && !defined(CONFIG_ALT_LB_ADDR)reserve_logbuffer,
#endif
#ifdef CONFIG_PRAMreserve_pram,
#endifreserve_round_4k,
#if !(defined(CONFIG_SYS_ICACHE_OFF) && defined(CONFIG_SYS_DCACHE_OFF)) && \defined(CONFIG_ARM)reserve_mmu,
#endif
#ifdef CONFIG_DM_VIDEOreserve_video,
#else
# ifdef CONFIG_LCDreserve_lcd,
# endif/* TODO: Why the dependency on CONFIG_8xx? */
# if defined(CONFIG_VIDEO) && (!defined(CONFIG_PPC) || defined(CONFIG_8xx)) && \!defined(CONFIG_ARM) && !defined(CONFIG_X86) && \!defined(CONFIG_BLACKFIN) && !defined(CONFIG_M68K)reserve_legacy_video,
# endif
#endif /* CONFIG_DM_VIDEO */reserve_trace,
#if !defined(CONFIG_BLACKFIN)reserve_uboot,
#endif
#ifndef CONFIG_SPL_BUILDreserve_malloc,reserve_board,
#endifsetup_machine,reserve_global_data,reserve_fdt,reserve_arch,reserve_stacks,setup_dram_config,show_dram_config,
#if defined(CONFIG_PPC) || defined(CONFIG_M68K) || defined(CONFIG_MIPS)setup_board_part1,
#endif
#if defined(CONFIG_PPC) || defined(CONFIG_M68K)INIT_FUNC_WATCHDOG_RESETsetup_board_part2,
#endifdisplay_new_sp,
#ifdef CONFIG_SYS_EXTBDINFOsetup_board_extra,
#endifINIT_FUNC_WATCHDOG_RESETreloc_fdt,setup_reloc,
#if defined(CONFIG_X86) || defined(CONFIG_ARC)copy_uboot_to_ram,clear_bss,do_elf_reloc_fixups,
#endif
#if !defined(CONFIG_ARM) && !defined(CONFIG_SANDBOX)jump_to_copy,
#endifNULL,
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