#include <stdio.h>
 
 
/**
 * hello.c
 */
 
 
#include <stdlib.h>
#include <string.h>
#include <elf.h> 
#include <errno.h>
#include "rtthread.h"
 
 
 
//#define FILE     ft_file_struct
//#define fclose   ft_if_fclose
//#define fopen    ft_if_fopen
//#define fread    ft_if_fread
//#define fseek    ft_if_fseek
//#define ftell    ft_if_ftell
 


 

 
static appm_list_struct g_app_list={0};



//找到一个空的app结构体
static app_struct *appm_new(void)
{
	if(g_app_list.used<APPM_LIST_MAXLEN)
	{
		for(int i=0;i<APPM_LIST_MAXLEN;i++)
		{
			app_struct *ptr=&g_app_list.app[i];
			if(ptr->exe_addr==0)
			{
				g_app_list.used++;
				return ptr;
			}
		}
	}
	return 0;
}




static int appm_delete (app_struct *app)
{
	if(app==0) return -1;
    for(int i=0;i<APPM_LIST_MAXLEN;i++)
    {
        app_struct *ptr=&g_app_list.app[i];
        if(ptr==app)
        {
            memset(ptr,0,sizeof(app_struct));
            g_app_list.used--;
            return 0;
        }
    }
	return -1;
}

app_struct * appm_find (char *name)
{
    for(int i=0;i<APPM_LIST_MAXLEN;i++)
    {
        app_struct *ptr=&g_app_list.app[i];
        if(strcmp(ptr->app_info->name,name)==0)
        {
            return ptr;
        }
    }
	return 0;
}

app_struct *appm_get(int index)
{
	if(index>=0&&index<APPM_LIST_MAXLEN)
	{
		if(g_app_list.app[index].exe_addr)
			return &g_app_list.app[index];
		else
			return 0;
	}
	return 0;
}



// 获取当前正在运行的app数目
int appm_get_running_num(void)
{
    int ret=0;
    for(int i=0;i<APPM_LIST_MAXLEN;i++)
    {
        app_struct *ptr=&g_app_list.app[i];
        if(ptr->run_state) ret++;
    }
	return ret;
}


 
/**elf 文件头和section表解析和检查***/
static int check_elf_head(app_struct * app )
{
	if(app==0) return -1;
	FILE *file_elf = app->file;
	if(file_elf==0) return -1;
	int i = 0;
	int MagNum = 0;
	unsigned long  file_size = 0;
	int sechnum = 0;
	uint32_t symsize = 0;
	uint32_t symoff = 0;
	uint32_t nSyms = 0,kk=0;
	Elf32_Ehdr *Elf_header = malloc(sizeof(Elf32_Ehdr));
 
 
	/*文件大小*/
	fseek(file_elf,0,SEEK_END);
	file_size = ftell(file_elf);
	fseek(file_elf,0,SEEK_SET);
	printf("file total size is:%ld bytes\r\n",file_size);
	fread(Elf_header,sizeof(Elf32_Ehdr),1,file_elf);	

	
	/**确认是否为elf格式**/
	if((Elf_header->e_ident[EI_MAG0] == ELFMAG0) && (Elf_header->e_ident[EI_MAG1] == ELFMAG1) \
		&& (Elf_header->e_ident[EI_MAG2] == ELFMAG2) && (Elf_header->e_ident[EI_MAG3] == ELFMAG3))
	{	
		printf("This is ELF file!\r\n");
	}
	else
	{
		printf("NOT ELF file!\r\n");
		free(Elf_header);
		return -1;
	}
	
	
	free(Elf_header);
	
	
	
	return 0;
}
 
 
/* 加载elf文件segment 到内存中 */
static int load_elf_2_mem(app_struct * app)
{
	
	if(app==0) return -1;
	
	Elf32_Phdr *phdr_head = NULL;
	Elf32_Ehdr *Elf_header = NULL;
	FILE *file1 = app->file;
	uint32_t rb;
	
 
	Elf_header = (Elf32_Ehdr *)malloc(sizeof(Elf32_Ehdr));
	memset(Elf_header,0,sizeof(Elf32_Ehdr));
 
	fseek(file1,0,SEEK_SET);
	rb = fread(Elf_header, sizeof(Elf32_Ehdr), 1, file1);
	
	/* 这里 Elf_header->e_phentsize 应该是== sizeof(Elf32_Phdr)*/
	phdr_head=malloc(Elf_header->e_phentsize *Elf_header->e_phnum);
	fseek(file1,Elf_header->e_phoff,SEEK_SET);
	fread(phdr_head,Elf_header->e_phentsize,Elf_header->e_phnum,file1);

	
	//Elf_header->e_phnum一般等于1
	for(int i=0;i< Elf_header->e_phnum; i++)
	{
		//是程序节
		//Keil编译的时候程序分为RO，RW，ZI，3个节，但是从运行时角度看来这3个节合并为一个段了
		if(phdr_head[i].p_type == PT_LOAD )
		{	
			//内存
			if(app->exe_addr==0) 
			{
				app->exe_addr=malloc(phdr_head[i].p_memsz);
				fseek( file1,phdr_head[i].p_offset,SEEK_SET);
				if((rb = fread(app->exe_addr,1,phdr_head[i].p_filesz,file1)) != phdr_head[i].p_filesz)
				{
					printf("function:%s,line:%d, read p_vaddr err!\r\n",__FUNCTION__,__LINE__);
					printf("read 返回值%d\r\n",rb);
					printf("read(file,ProHead->p_vaddr,ProHead->p_filesz) != ProHead->p_filesz %x  p_filesz %d\r\n",\
						phdr_head[i].p_vaddr,phdr_head[i].p_filesz);
				}
				
				/**多余的空间写0，做BSS段**/
				if((phdr_head[i].p_filesz) < (phdr_head[i].p_memsz))
				{
					memset((uint8_t*)app->exe_addr+phdr_head[i].p_filesz,
							0,
							phdr_head[i].p_memsz - phdr_head[i].p_filesz);
				}
				
				//找到入口函数地址
				app->main=(int (*)(void *))((int)app->exe_addr+Elf_header->e_entry);
				
				//程序描述信息地址
				app->app_info=(app_info_struct *)app->exe_addr;
				
				printf("%s:exe_addr=0X%08X,size=%d\r\n",__func__,(uint32_t)app->exe_addr,phdr_head[i].p_memsz);
				printf("%s:main()=0X%08X\r\n",__func__,(uint32_t)app->main);
				printf("%s:name=%s\r\n",__func__,app->app_info->name);
				
				break;
			}
		}

		
	}
	
	
	//这里求得RW区在程序映像中的偏移
	Elf32_Shdr *sher_head=NULL;
	sher_head=malloc(Elf_header->e_shentsize *Elf_header->e_shnum);
	fseek(file1,Elf_header->e_shoff,SEEK_SET);
	fread(sher_head,Elf_header->e_shentsize,Elf_header->e_shnum,file1);
	
	for(int i=0;i<Elf_header->e_shnum;i++)
	{
		if((sher_head[i].sh_type==SHT_PROGBITS)&&(sher_head[i].sh_flags==(SHF_ALLOC|SHF_EXECINSTR)))
		{
			app->ro_size=sher_head[i].sh_size;
			break;
		}
	}
	free(sher_head);
	
	
	free(Elf_header);
	free(phdr_head);
	
	
	return 0;
}


//关闭app文件
static void app_close(app_struct *app)
{
	if(app==0) return;
	if(app->file) fclose(app->file);
}

//打开app文件
static int app_open(app_struct *app,char *path)
{
	if(app==0) return -1;
	app->file=fopen(path,"rb");
	if(app->file)
	{
		return 0;
	}
	else
		return -1;
}
 






//从文件中获取app的名称
//name,用于保存文件名的数组，长度必须不小于APP_INFO_NAME_MAXLEN
//返回正数成功，0失败，正数代表程序的类型
int app_get_name_from_file(char *path,char *name)
{
	
	if(path==0) return 0;
	if(name==0) return 0;
	
	Elf32_Phdr *phdr_head = NULL;
	Elf32_Ehdr *Elf_header = NULL;
	FILE *file1 = fopen(path,"rb");
	uint32_t rb;
	if(file1==0) return 0;
 
	Elf_header = (Elf32_Ehdr *)malloc(sizeof(Elf32_Ehdr));
	memset(Elf_header,0,sizeof(Elf32_Ehdr));
 
	fseek(file1,0,SEEK_SET);
	rb = fread(Elf_header, sizeof(Elf32_Ehdr), 1, file1);
	
	/* 这里 Elf_header->e_phentsize 应该是== sizeof(Elf32_Phdr)*/
	phdr_head=malloc(Elf_header->e_phentsize *Elf_header->e_phnum);
	fseek(file1,Elf_header->e_phoff,SEEK_SET);
	fread(phdr_head,Elf_header->e_phentsize,Elf_header->e_phnum,file1);

	
	//Elf_header->e_phnum一般等于1
	for(int i=0;i< Elf_header->e_phnum; i++)
	{
		//是程序节
		//Keil编译的时候程序分为RO，RW，ZI，3个节，但是从运行时角度看来这3个节合并为一个段了
		if(phdr_head[i].p_type == PT_LOAD )
		{
			fseek( file1,phdr_head[i].p_offset,SEEK_SET);
			if((rb = fread(name,1,APP_INFO_NAME_MAXLEN,file1)) == APP_INFO_NAME_MAXLEN)
			{
				int app_type=0;
				fread(&app_type,1,sizeof(int),file1);
				fclose(file1);
				free(Elf_header);
				free(phdr_head);
				return app_type;
			}
		}
	}
	
	fclose(file1);
	free(Elf_header);
	free(phdr_head);
	return 0;
}




//app退出运行 0,成功，非0，失败
int app_exit(app_struct *app)
{
	if(app==0) return -1;
	
	//如果app正在运行，需要先退出app
	if(app->run_state&&app->exit)
	{
		app->exit(0);
	}
	if(app->run_state==0)
	{
		//在app没有运行时才可以删除
		if(app->exe_addr) free(app->exe_addr);
		appm_delete(app);
		return 0;
	}
	else
	{
		return -1;
	}
}


//获取和保存r9寄存器
void *get_r9(void);
void set_r9(void *r9);

 
//抢占式调用app，阻塞调用线程以运行app
static int app_run_seize(app_struct *app)
{
	int ret=0;
	
	
	app->r9=get_r9();
	set_r9((void *)((int)app->exe_addr+app->ro_size));
	if (app->main) app->main(app);
	set_r9(app->r9);
	
	app_exit(app);
	
	
	
	return ret;
}

//调用app，保留app镜像
static int app_run_hold(app_struct *app)
{
	int ret=0;
	if(app==0) return -1;
	
	app->r9=get_r9();
	set_r9((void *)((int)app->exe_addr+app->ro_size));
	if (app->main) app->main(app);
	set_r9(app->r9);
	
	
	
	
	return ret;
}



static void run_thread_entry(void *t)
{
	app_struct *app=t;
	int ret=0;
	
		
	app->r9=get_r9();
	set_r9((void *)((int)app->exe_addr+app->ro_size));
	if (app->main) app->main(app);
	set_r9(app->r9);
		
	app_exit(app);
	
}



//创建新线程以运行app
static int app_run_thread(app_struct *app)
{
	int ret=0;
	
	
	rt_thread_t rt=rt_thread_create(app->app_info->name,run_thread_entry,app,
			app->app_info->stack_size,app->app_info->priority,20);
	rt_thread_startup(rt);
	ret=0;
	
	
	
	return ret;
}

//运行app
int app_run(app_struct *app)
{
	int ret=0;
	if(app->app_info->exe_type==APP_TYPE_SEIZE)
	{
		ret=app_run_seize(app);
	}
	else if(app->app_info->exe_type==APP_TYPE_THREAD)
	{
		ret=app_run_thread(app);
	}
	else if(app->app_info->exe_type==APP_TYPE_HOLD)
	{
		ret=app_run_hold(app);
	}
	return ret;
}


int app_run_path(char *path)
{
	int ret=0;
	
	//如果程序已经存在于内存中，则直接调用
	char name[APP_INFO_NAME_MAXLEN]={0};
	if(app_get_name_from_file(path,name)!=0)
	{
		app_struct *app=appm_find(name);
		if(app)
		{
			if(app->app_info->exe_type==APP_TYPE_HOLD)
			{
				ret=app_run_hold(app);
			}
			return ret;
		}
	}
	
	app_struct *app=appm_new();
	
	if((app_open(app,path)==0)&&(check_elf_head(app)==0)&&(load_elf_2_mem(app)==0))
	{
		app_close(app);
		app_run(app);
	}
	else
	{
		appm_delete(app);
		ret=-1;
	}
	
	
	
	
	return ret;
}