almost got the term emu working and shell

This commit is contained in:
2026-07-08 21:15:30 -05:00
parent ec3cbb4794
commit 4d98d73f5e
20 changed files with 214 additions and 228 deletions

View File

@@ -64,65 +64,14 @@ void load_root_program(const char* path) {
load_pd(cr3);
flush_tlb();
int fd = open(path, 0);
if (fd == -1) {
kprintf("failed to open program: %s\n", path);
return;;
}
elf_header_t* e_hdr = kalloc(sizeof(elf_header_t));
memset((void*)e_hdr, 0, sizeof(elf_header_t));
uint32_t bytes_rd = read(fd, e_hdr, sizeof(elf_header_t));
if (bytes_rd <= 0) {
kprintf("failed to read program data for %s\n", path);
return;
}
uint32_t ph_table_ptr = e_hdr->e_phoff;
elf_program_header_t* ph = kalloc(sizeof(elf_program_header_t));
uint32_t heap_start = 0;
for (uint32_t i = 0; i < e_hdr->e_phnum; i++) {
fseek(fd, ph_table_ptr);
memset((void*)ph, 0, sizeof(elf_program_header_t));
read(fd, ph, sizeof(elf_program_header_t));
if (ph->p_type == PT_LOAD) {
uint32_t vstart = ph->p_vaddr;
uint32_t vend = vstart + ph->p_memsz;
if (vend > heap_start) {
heap_start = vend;
}
uint32_t page_start = vstart & ~(PAGE_SIZE - 1);
uint32_t page_end = (vend + PAGE_SIZE - 1) & ~(PAGE_SIZE - 1);
for (uint32_t v = page_start; v < page_end; v += PAGE_SIZE) {
void* phys_frame = p_alloc_frame();
map_page(v, (uint32_t)phys_frame, PAGE_PRESENT | PAGE_WRITABLE | PAGE_USER);
}
uint32_t data_ptr = ph->p_offset;
fseek(fd, data_ptr);
read(fd, (void*)vstart, ph->p_filesz);
// 0 out bss
if (ph->p_memsz > ph->p_filesz) {
size_t bss_size = ph->p_memsz - ph->p_filesz;
memset((void*)(vstart + ph->p_filesz), 0, bss_size);
}
}
ph_table_ptr += sizeof(elf_program_header_t);
}
uint32_t eip = load_elf_program(path);
uint32_t stack_sz = PAGE_SIZE * 16;
uint32_t stack_top = 0xBFFF0000;
uint32_t stack_bottom = stack_top - stack_sz;
for (uint32_t vaddr = stack_bottom; vaddr < stack_top; vaddr += PAGE_SIZE) {
void* phys_frame = p_alloc_frame();
map_page(vaddr, (uint32_t)phys_frame, PAGE_PRESENT | PAGE_WRITABLE | PAGE_USER);
void* phys_frame = p_alloc_frame();
map_page(vaddr, (uint32_t)phys_frame, PAGE_PRESENT | PAGE_WRITABLE | PAGE_USER);
}
uint32_t* u_esp = (uint32_t*)stack_top;
@@ -131,7 +80,7 @@ void load_root_program(const char* path) {
*(--u_esp) = 0; // argc = 0
process_t* process = kalloc(sizeof(process_t));
init_task(process, e_hdr->e_entry, (uint32_t)cr3, 1, (uint32_t)u_esp);
init_task(process, eip, (uint32_t)cr3, 1, (uint32_t)u_esp);
add_task(process);
unlock_scheduler();
@@ -164,8 +113,8 @@ void kmain(uint32_t magic, multiboot_info* mbi) {
kprintf("basic initializations complete\n");
vfs_node_t* vfs_root = vfs_create_root();
vfs_node_t* initrd_root = load_initrd();
if (!initrd_root) {
kprintf("failed to load initrd\n");
}
@@ -177,8 +126,8 @@ void kmain(uint32_t magic, multiboot_info* mbi) {
init_scheduler();
enable_interrupts();
kprintf("loading test program\n");
load_root_program("/test.elf");
kprintf("loading terminal program\n");
load_root_program("/vga_text_term.elf");
kprintf("kernel going to sleep...\n");
}