/*******************************************************************************/ /* COS2000 - Compatible Operating System - LGPL v3 - Hordé Nicolas */ /* */ #include "types.h" #include "process.h" #include "memory.h" #include "gdt.h" process *processes; process *current; u32 lastpid; static u8 elf_errors1[]="Aucune signature ELF"; static u8 elf_errors2[]="Fichier au format ELF mais non 32 bits"; static u8 elf_errors3[]="ELF non LSB"; static u8 elf_errors4[]="ELF mauvaise version"; static u8 elf_errors5[]="ELF pour OS ne correspondant pas"; static u8 elf_errors6[]="Mauvais type de machine"; static u8 *elf_errors[]={&elf_errors1,&elf_errors2,&elf_errors3,&elf_errors4,&elf_errors5,&elf_errors6}; /*******************************************************************************/ /* Vérifie la signature ELF 0 - RAS 1 - Pas la signature ELF 2 - pas ELF32 3 - pas bon organisation LSB/MSB 4 - pas bonne version ELF 5 - pas bon OS 6 - pas bon type machine */ u32 elf_test(u8 *src) { elf32 *header=(elf32 *) src; if (header->e_ident[EI_MAG0] == ELFMAG0 && header->e_ident[EI_MAG1] == ELFMAG1 && header->e_ident[EI_MAG2] == ELFMAG2 && header->e_ident[EI_MAG3] == ELFMAG3) { if (header->e_ident[EI_CLASS]!=ELFCLASS32) return 2; if (header->e_ident[EI_DATA]!=ELFDATA2LSB) return 3; if (header->e_ident[EI_VERSION]!=EV_CURRENT || header->e_version!=EV_CURRENT) return 4; if (header->e_ident[EI_OSABI]!=ELFOSABI_COS2000) return 5; if (header->e_machine!=EM_386) return 6; return 0; } else return 1; } /*******************************************************************************/ /* Charge le fichier ELF en mémoire et mets à jour les informations sur le processus */ u32 elf_load(u8 *src, u32 pid) { u8 *ptr; u8 code; u32 v_begin, v_end; elf32 *header; elf32p *program; u32 i; header = (elf32 *) src; program = (elf32p *) (src + header->e_phoff); code=elf_test(src); if (code!=0) { printf("Erreur de chargement ELF, %s !\r\n",elf_errors[code-1]); return NULL; } for (i = 0; i < header->e_phnum; i++, program++) { if (program->p_type == PT_LOAD) { v_begin = program->p_vaddr; v_end = program->p_vaddr + program->p_memsz; if (v_begin < USER_CODE) { printf ("Ne peut charger l'executable en desssous de l'adresse %X\r\n", USER_CODE); return 0; } if (v_end > USER_STACK) { printf ("Ne peut charger l'executable au desssus de l'adresse %X\r\n", USER_STACK); return 0; } if (program->p_flags == PF_X + PF_R) { processes[pid].exec_low = (u8*) v_begin; processes[pid].exec_high = (u8*) v_end; } if (program->p_flags == PF_W + PF_R) { processes[pid].bss_low = (u8*) v_begin; processes[pid].bss_high = (u8*) v_end; } memcpy((u8 *) (src + program->p_offset),(u8 *) v_begin , program->p_filesz,0); if (program->p_memsz > program->p_filesz) for (i = program->p_filesz, ptr = (u8 *) program->p_vaddr; i < program->p_memsz; i++) ptr[i] = 0; } } processes[pid].entry=header->e_entry; return header->e_entry; } /*******************************************************************************/ /* Initialise la liste des processus */ void task_init() { u32 i=0; processes=(process*)vmalloc(sizeof(process)*MAXNUMPROCESS); while (i++ < MAXNUMPROCESS) { processes[i].pid=NULL; processes[i].status=STATUS_FREE; } current=NULL; lastpid=NULL; } /*******************************************************************************/ /* Récupère un emplacement dans la liste des processus */ u32 task_getfreePID () { u32 i = lastpid; u32 parsed = 0; while (processes[++i].status != STATUS_FREE && ++parsed < MAXNUMPROCESS) { if (i>=MAXNUMPROCESS) i=0; } if (parsed>MAXNUMPROCESS) { printf("PANIC: plus d'emplacement disponible pour un novueau processus\n"); return NULL; } return i; } /*******************************************************************************/ /* Récupère les informations sur le processus courant */ process *getcurrentprocess() { return current; } /*******************************************************************************/ /* Determine le dernier PID occupé */ u32 task_usePID (u32 pid) { lastpid=pid; } /*******************************************************************************/ /* Bascule vers une tâche */ void task_switch(u32 pid, bool fromkernelmode) { u32 ss,esp,eflags; current = &processes[pid]; setTSS(current->kstack.ss0,current->kstack.esp0); eflags = (current->dump.eflags | 0x200) & 0xFFFFBFFF; if (fromkernelmode) { ss = current->dump.ss; esp = current->dump.esp; } else { ss = current->kstack.ss0; esp = current->kstack.esp0; } createdump(¤t->dump); restdebugcpu(); } /*******************************************************************************/ /* Execute une tâche */ void task_run(u32 pid) { processes[pid].status = STATUS_RUN; task_switch(pid, true); } /*******************************************************************************/ /* Initialise une tâche */ u32 task_create(u8 *code) { process *previous=current; u32 pid=task_getfreePID(); task_usePID(pid); page *kstack; processes[pid].pid = pid; processes[pid].pdd = virtual_pd_create(); TAILQ_INIT(&processes[pid].page_head); current = &processes[pid]; setcr3(processes[pid].pdd->addr->paddr); kstack = virtual_page_getfree(); processes[pid].dump.ss = SEL_USER_STACK | RPL_RING3; processes[pid].dump.esp = USER_STACK; processes[pid].dump.eflags = 0x0; processes[pid].dump.cs = SEL_USER_CODE | RPL_RING3; processes[pid].dump.eip = elf_load(code,pid); if (processes[pid].dump.eip==NULL) return NULL; processes[pid].dump.ds = SEL_USER_DATA | RPL_RING3; processes[pid].dump.es = SEL_USER_DATA | RPL_RING3; processes[pid].dump.fs = SEL_USER_DATA | RPL_RING3; processes[pid].dump.gs = SEL_USER_DATA | RPL_RING3; processes[pid].dump.cr3 = (u32) processes[pid].pdd->addr->paddr; processes[pid].kstack.ss0 = SEL_KERNEL_STACK; processes[pid].kstack.esp0 = (u32) kstack->vaddr + PAGESIZE - 16; processes[pid].dump.eax = 0; processes[pid].dump.ecx = 0; processes[pid].dump.edx = 0; processes[pid].dump.ebx = 0; processes[pid].dump.ebp = 0; processes[pid].dump.esi = 0; processes[pid].dump.edi = 0; processes[pid].result = 0; processes[pid].status = STATUS_READY; current = previous; if (current==NULL) { u32 pd = KERNEL_PD_ADDR; setcr3(pd); } else { setcr3(current->dump.cr3); } return pid; }