高通Qualcomm平台lk（light kernel）启动流程1——aboot_init()之前

更多相关文章：

《高通Qualcomm平台lk（light kernel）启动流程1——aboot_init()之前》：
http://blog.csdn.net/u014134180/article/details/78133916
《高通Qualcomm平台lk（light kernel）启动流程2——aboot_init()》：
http://blog.csdn.net/u014134180/article/details/78132580
《高通Qualcomm平台lk（light kernel）启动流程3——到高通lcm屏点亮》：
http://blog.csdn.net/u014134180/article/details/78177040

《[lcm] Qualcomm Android Display Subsystem 架构》
http://blog.csdn.net/u014134180/article/details/78129502

《[lcm] Qualcomm平台的显示屏lcd驱动移植步骤》：
http://blog.csdn.net/u014134180/article/details/78129499
《[lcm] Qualcomm平台兼容多显示屏lcd的方法&并从lk传输到kernel过程》:
http://blog.csdn.net/u014134180/article/details/78166978
《[lcm] Qualcomm平台显示屏lcd添加I2C读取功能》：
http://blog.csdn.net/u014134180/article/details/78176160

0、lk 启动总体流程

1、lk启动流程代码

lk/ arch/ arm/ crt0.S

/* * Copyright (c) 2008 Travis Geiselbrecht * * Copyright (c) 2014, The Linux Foundation. All rights reserved. * * Permission is hereby granted, free of charge, to any person obtaining * a copy of this software and associated documentation files * (the "Software"), to deal in the Software without restriction, * including without limitation the rights to use, copy, modify, merge, * publish, distribute, sublicense, and/or sell copies of the Software, * and to permit persons to whom the Software is furnished to do so, * subject to the following conditions: * * The above copyright notice and this permission notice shall be * included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */#define DSB .byte 0x4f, 0xf0, 0x7f, 0xf5#define ISB .byte 0x6f, 0xf0, 0x7f, 0xf5.section ".text.boot".globl _start_start:    b   reset    b   arm_undefined    b   arm_syscall    b   arm_prefetch_abort    b   arm_data_abort    b   arm_reserved    b   arm_irq    b   arm_fiqreset:#ifdef ENABLE_TRUSTZONE    /*Add reference to TZ symbol so linker includes it in final image */    ldr r7, =_binary_tzbsp_tzbsp_bin_start#endif    /* do some cpu setup */#if ARM_WITH_CP15        /* Read SCTLR */    mrc     p15, 0, r0, c1, c0, 0        /* XXX this is currently for arm926, revist with armv6 cores */        /* new thumb behavior, low exception vectors, i/d cache disable, mmu disabled */    bic     r0, r0, #(1<<15| 1<<13 | 1<<12)    bic     r0, r0, #(1<<2 | 1<<0)        /* disable alignment faults */    bic     r0, r0, #(1<<1)    /* Enable CP15 barriers by default */#ifdef ARM_CORE_V8    orr     r0, r0, #(1<<5)#endif        /* Write SCTLR */    mcr     p15, 0, r0, c1, c0, 0#ifdef ENABLE_TRUSTZONE  /*nkazi: not needed ? Setting VBAR to location of new vector table : 0x80000      */ ldr             r0, =0x00080000 mcr             p15, 0, r0, c12, c0, 0#endif#endif#if WITH_CPU_EARLY_INIT    /* call platform/arch/etc specific init code */#ifndef ENABLE_TRUSTZONE    /* Not needed when TrustZone is the first bootloader that runs.*/    bl __cpu_early_init#endif    /* declare return address as global to avoid using stack */.globl _cpu_early_init_complete    _cpu_early_init_complete:#endif#if (!ENABLE_NANDWRITE)#if WITH_CPU_WARM_BOOT    ldr     r0, warm_boot_tag    cmp     r0, #1    /* if set, warm boot */    ldreq   pc, =BASE_ADDR    mov     r0, #1    str r0, warm_boot_tag#endif#endif    /* see if we need to relocate */    mov     r0, pc    sub     r0, r0, #(.Laddr - _start).Laddr:    ldr     r1, =_start    cmp     r0, r1    beq     .Lstack_setup    /* we need to relocate ourselves to the proper spot */    ldr     r2, =__data_end .Lrelocate_loop:    ldr     r3, [r0], #4    str     r3, [r1], #4    cmp     r1, r2    bne     .Lrelocate_loop    /* we're relocated, jump to the right address */    ldr     r0, =.Lstack_setup    bx      r0.ltorg#if WITH_CPU_WARM_BOOTwarm_boot_tag:    .word 0#endif.Lstack_setup:    /* set up the stack for irq, fiq, abort, undefined, system/user, and lastly supervisor mode */    mrs     r0, cpsr    bic     r0, r0, #0x1f    ldr     r2, =abort_stack_top    orr     r1, r0, #0x12 // irq    msr     cpsr_c, r1    ldr     r13, =irq_save_spot     /* save a pointer to a temporary dumping spot used during irq delivery */    orr     r1, r0, #0x11 // fiq    msr     cpsr_c, r1    mov     sp, r2    orr     r1, r0, #0x17 // abort    msr     cpsr_c, r1    mov     sp, r2    orr     r1, r0, #0x1b // undefined    msr     cpsr_c, r1    mov     sp, r2    orr     r1, r0, #0x1f // system    msr     cpsr_c, r1    mov     sp, r2    orr     r1, r0, #0x13 // supervisor    msr     cpsr_c, r1    mov     sp, r2    /* copy the initialized data segment out of rom if necessary */    ldr     r0, =__data_start_rom    ldr     r1, =__data_start    ldr     r2, =__data_end    cmp     r0, r1    beq     .L__do_bss.L__copy_loop:    cmp     r1, r2    ldrlt   r3, [r0], #4    strlt   r3, [r1], #4    blt     .L__copy_loop.L__do_bss:    /* clear out the bss */    ldr     r0, =__bss_start    ldr     r1, =_end    mov     r2, #0.L__bss_loop:    cmp     r0, r1    strlt   r2, [r0], #4    blt     .L__bss_loop#ifdef ARM_CPU_CORTEX_A8    DSB    ISB#endif    bl      kmain    b       ..ltorg.bss.align 2    /* the abort stack is for unrecoverable errors.     * also note the initial working stack is set to here.     * when the threading system starts up it'll switch to a new      * dynamically allocated stack, so we don't need it for very long     */abort_stack:    .skip 1024abort_stack_top:

lk/ kernel/ main.c

/* * Copyright (c) 2008 Travis Geiselbrecht * * Copyright (c) 2009-2014, The Linux Foundation. All rights reserved. * * Permission is hereby granted, free of charge, to any person obtaining * a copy of this software and associated documentation files * (the "Software"), to deal in the Software without restriction, * including without limitation the rights to use, copy, modify, merge, * publish, distribute, sublicense, and/or sell copies of the Software, * and to permit persons to whom the Software is furnished to do so, * subject to the following conditions: * * The above copyright notice and this permission notice shall be * included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */#include <compiler.h>#include <debug.h>#include <string.h>#include <app.h>#include <arch.h>#include <platform.h>#include <target.h>#include <lib/heap.h>#include <kernel/thread.h>#include <kernel/timer.h>#include <kernel/dpc.h>#include <boot_stats.h>extern void *__ctor_list;extern void *__ctor_end;extern int __bss_start;extern int _end;static int bootstrap2(void *arg);#if (ENABLE_NANDWRITE)void bootstrap_nandwrite(void);#endifstatic void call_constructors(void){    void **ctor;    ctor = &__ctor_list;    while(ctor != &__ctor_end) {        void (*func)(void);        func = (void (*)())*ctor;        func();        ctor++;    }}/* called from crt0.S */void kmain(void) __NO_RETURN __EXTERNALLY_VISIBLE;void kmain(void){    thread_t *thr;    // get us into some sort of thread context    thread_init_early();    // early arch stuff    arch_early_init();    // do any super early platform initialization    platform_early_init();    // do any super early target initialization    target_early_init();    dprintf(INFO, "welcome to lk\n\n");    bs_set_timestamp(BS_BL_START);    // deal with any static constructors    dprintf(SPEW, "calling constructors\n");    call_constructors();    // bring up the kernel heap    dprintf(SPEW, "initializing heap\n");    heap_init();    __stack_chk_guard_setup();    // initialize the threading system    dprintf(SPEW, "initializing threads\n");    thread_init();    // initialize the dpc system    dprintf(SPEW, "initializing dpc\n");    dpc_init();    // initialize kernel timers    dprintf(SPEW, "initializing timers\n");    timer_init();#if (!ENABLE_NANDWRITE)    // create a thread to complete system initialization    dprintf(SPEW, "creating bootstrap completion thread\n");    thr = thread_create("bootstrap2", &bootstrap2, NULL, DEFAULT_PRIORITY, DEFAULT_STACK_SIZE);    if (!thr)    {        panic("failed to create thread bootstrap2\n");    }    thread_resume(thr);    // enable interrupts    exit_critical_section();    // become the idle thread    thread_become_idle();#else        bootstrap_nandwrite();#endif}int main(void);static int bootstrap2(void *arg){    dprintf(SPEW, "top of bootstrap2()\n");    arch_init();    // XXX put this somewhere else#if WITH_LIB_BIO    bio_init();#endif#if WITH_LIB_FS    fs_init();#endif    // initialize the rest of the platform    dprintf(SPEW, "initializing platform\n");    platform_init();    // initialize the target    dprintf(SPEW, "initializing target\n");    target_init();    dprintf(SPEW, "calling apps_init()\n");    apps_init();    return 0;}#if (ENABLE_NANDWRITE)void bootstrap_nandwrite(void){    dprintf(SPEW, "top of bootstrap2()\n");    arch_init();    // initialize the rest of the platform    dprintf(SPEW, "initializing platform\n");    platform_init();    // initialize the target    dprintf(SPEW, "initializing target\n");    target_init();    dprintf(SPEW, "calling nandwrite_init()\n");    nandwrite_init();    return 0;}#endif

lk/ app/ app.c

/* * Copyright (c) 2009 Travis Geiselbrecht * * Permission is hereby granted, free of charge, to any person obtaining * a copy of this software and associated documentation files * (the "Software"), to deal in the Software without restriction, * including without limitation the rights to use, copy, modify, merge, * publish, distribute, sublicense, and/or sell copies of the Software, * and to permit persons to whom the Software is furnished to do so, * subject to the following conditions: * * The above copyright notice and this permission notice shall be * included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */#include <debug.h>#include <app.h>#include <kernel/thread.h>extern const struct app_descriptor __apps_start;extern const struct app_descriptor __apps_end;static void start_app(const struct app_descriptor *app);/* one time setup */void apps_init(void){    const struct app_descriptor *app;    /* call all the init routines */    for (app = &__apps_start; app != &__apps_end; app++) {        if (app->init)            app->init(app);    }    /* start any that want to start on boot */    for (app = &__apps_start; app != &__apps_end; app++) {        if (app->entry && (app->flags & APP_FLAG_DONT_START_ON_BOOT) == 0) {            start_app(app);        }    }}static int app_thread_entry(void *arg){    const struct app_descriptor *app = (const struct app_descriptor *)arg;    app->entry(app, NULL);    return 0;}static void start_app(const struct app_descriptor *app){    thread_t *thr;    printf("starting app %s\n", app->name);    thr = thread_create(app->name, &app_thread_entry, (void *)app, DEFAULT_PRIORITY, DEFAULT_STACK_SIZE);    if(!thr)    {        return;    }    thread_resume(thr);}

Wu_Being博客声明：本人博客欢迎转载，请标明博客原文和原链接！谢谢！
《高通Qualcomm平台lk（light kernel）启动流程1——aboot_init()之前》： http://blog.csdn.net/u014134180/article/details/78133916

如果你看完这篇博文，觉得对你有帮助，并且愿意付赞助费，那么我会更有动力写下去。