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

0lk 启动总体流程

1lk启动流程代码
lk arch arm crt0S

lk kernel mainc

lk app appc

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_fiq

reset:

#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_BOOT
warm_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 1024
abort_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);
#endif

static 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);
}

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《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



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