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#include <hilbert/kernel/storage/bd/memory.hpp>
#include <hilbert/kernel/storage/fs/tarfs.hpp>
#include <hilbert/kernel/application.hpp>
#include <hilbert/kernel/framebuffer.hpp>
#include <hilbert/kernel/terminal.hpp>
#include <hilbert/kernel/paging.hpp>
#include <hilbert/kernel/vfile.hpp>
#include "../limine/limine.h"
using namespace hilbert::kernel;
LIMINE_BASE_REVISION(1)
static volatile limine_memmap_request memmap_request {
.id = LIMINE_MEMMAP_REQUEST,
.revision = 0,
.response = 0
};
static volatile limine_kernel_address_request kernel_address_request {
.id = LIMINE_KERNEL_ADDRESS_REQUEST,
.revision = 0,
.response = 0
};
static volatile limine_framebuffer_request framebuffer_request {
.id = LIMINE_FRAMEBUFFER_REQUEST,
.revision = 0,
.response = 0
};
static volatile limine_hhdm_request hhdm_request {
.id = LIMINE_HHDM_REQUEST,
.revision = 0,
.response = 0
};
static limine_internal_module initfs_module = {
.path = "initfs.tgz",
.cmdline = "initfs",
.flags = LIMINE_INTERNAL_MODULE_REQUIRED | LIMINE_INTERNAL_MODULE_COMPRESSED
};
static limine_internal_module termfont_module = {
.path = "termfont.psf",
.cmdline = "termfont",
.flags = LIMINE_INTERNAL_MODULE_REQUIRED
};
static limine_internal_module *internal_modules[] = {
&initfs_module, &termfont_module
};
static volatile limine_module_request module_request = {
.id = LIMINE_MODULE_REQUEST,
.revision = 2,
.response = 0,
.internal_module_count = 2,
.internal_modules = internal_modules
};
bool try_map_module_by_cmdline(
const char *cmdline, void *&vaddr_out, uint64_t &len_out
) {
auto response = module_request.response;
for (uint64_t i = 0; i < response->module_count; ++i) {
limine_file *file = response->modules[i];
for (uint64_t j = 0; cmdline[j] == file->cmdline[j]; ++j)
if (!cmdline[j]) {
//module start is guaranteed to be page-aligned, end is not.
uint64_t start_paddr =
(uint64_t)file->address - hhdm_request.response->offset;
uint64_t end_paddr =
((start_paddr + file->size - 1) / 4096 + 1) * 4096;
uint64_t start_vaddr =
paging::find_unmapped_vram_region((end_paddr - start_paddr) / 4096);
for (uint64_t i = 0; i < end_paddr - start_paddr; i += 4096)
paging::map_kernel_page(
start_paddr + i, start_vaddr + i, true, false);
vaddr_out = (void *)start_vaddr;
len_out = file->size;
return true;
}
}
return false;
}
//defined in linker script, page-aligned:
extern uint8_t __kernel_start;
extern uint8_t __kernel_end;
extern uint8_t __kernel_rx_start;
extern uint8_t __kernel_rx_end;
extern uint8_t __kernel_ro_start;
extern uint8_t __kernel_ro_end;
extern uint8_t __kernel_rw_start;
extern uint8_t __kernel_rw_end;
uint8_t *initfs;
uint64_t initfs_len;
[[noreturn]] static void with_kernel_p4();
extern "C" void load_gdt_and_idt();
extern "C" [[noreturn]] void entry() {
//TODO?: maybe we should check if the limine requests were
// fulfilled and display some error message if not
//set up the physical memory usage bitmap:
paging::mark_all_pram_used();
auto memmap = memmap_request.response;
for (uint64_t i = 0; i < memmap->entry_count; ++i) {
//we don't allocate any physical pages until after we are done using limine
//structures (specifically at the call to paging::map_kernel_stacks), so
//we consider bootloader reclaimable to be free. usable and bootloader
//reclaimable are guaranteed by limine spec to be page-aligned.
auto entry = memmap->entries[i];
if (entry->type == LIMINE_MEMMAP_USABLE ||
entry->type == LIMINE_MEMMAP_BOOTLOADER_RECLAIMABLE)
paging::mark_pram_region_free(entry->base, entry->base + entry->length);
}
//set up page mappings:
auto kernel_address = kernel_address_request.response;
uint64_t kernel_offset = kernel_address->virtual_base
- kernel_address->physical_base;
uint64_t hhdm = hhdm_request.response->offset;
//framebuffer might not be page-aligned
auto framebuffer = framebuffer_request.response->framebuffers[0];
uint64_t fb_start = ((uint64_t)framebuffer->address / 4096) * 4096 - hhdm;
uint64_t fb_end = (uint64_t)framebuffer->address
+ framebuffer->pitch * framebuffer->height - hhdm;
fb_end = ((fb_end - 1) / 4096 + 1) * 4096;
paging::init_kernel_page_tables(kernel_offset);
//kernel image rx
for (uint64_t vaddr = (uint64_t)&__kernel_rx_start;
vaddr < (uint64_t)&__kernel_rx_end; vaddr += 4096)
paging::map_kernel_page(vaddr - kernel_offset, vaddr, false, true);
//kernel image ro
for (uint64_t vaddr = (uint64_t)&__kernel_ro_start;
vaddr < (uint64_t)&__kernel_ro_end; vaddr += 4096)
paging::map_kernel_page(vaddr - kernel_offset, vaddr, false, false);
//kernel image rw
for (uint64_t vaddr = (uint64_t)&__kernel_rw_start;
vaddr < (uint64_t)&__kernel_rw_end; vaddr += 4096)
paging::map_kernel_page(vaddr - kernel_offset, vaddr, true, false);
//framebuffer
uint64_t fb_vaddr =
paging::find_unmapped_vram_region((fb_end - fb_start) / 4096);
for (uint64_t i = 0; i < fb_end - fb_start; i += 4096)
paging::map_kernel_page(fb_start + i, fb_vaddr + i, true, false);
//initfs and termfont - these are required modules
//so there is no worry about them not being present.
try_map_module_by_cmdline("initfs", (void *&)initfs, initfs_len);
try_map_module_by_cmdline(
"termfont", (void *&)terminal::termfont, terminal::termfont_len);
//set up framebuffer and terminal:
//TODO: assumes framebuffer is 32-bpp rgb
framebuffer::init_framebuffer(fb_start, fb_vaddr,
framebuffer->width, framebuffer->height, framebuffer->pitch);
//switch to kernel p4
paging::map_kernel_stacks();
load_gdt_and_idt();
switch_to_kernel_p4(&with_kernel_p4);
}
[[noreturn]] static void print_and_halt(const char *msg) {
terminal::put_string_sz(msg);
while (1)
asm ("hlt");
}
extern "C" [[noreturn]] void start_user_mode(
uint64_t rip, uint64_t rsp, uint64_t p4_paddr);
[[noreturn]] static void with_kernel_p4() {
terminal::init_terminal();
auto *initfs_bd = new storage::bd::memory(initfs, initfs_len);
auto *initfs_fs = new storage::fs::tarfs_instance(initfs_bd);
initfs_bd->mounted_as = initfs_fs;
vfile::vfile initfs_root;
initfs_root.bd = initfs_bd;
initfs_root.dir_entry.type = storage::file_type::directory;
initfs_root.path.absolute = true;
if (initfs_fs->get_root_node(initfs_root.dir_entry.node) !=
storage::fs_result::success)
print_and_halt("failed to get root node of initfs.");
vfile::set_root(initfs_root);
utility::string init_path_string("/bin/init.elf", 13);
vfile::canon_path init_path;
vfile::canonize_path(init_path_string, init_path);
vfile::vfile init_file;
if (vfile::lookup_path(init_path, init_file) != storage::fs_result::success)
print_and_halt("failed to look up /bin/init.elf.");
application::app_instance *init;
if (application::create_app(init_file, init, initfs_root) !=
application::create_app_result::success)
print_and_halt("failed to parse /bin/init.elf.");
application::running_app = init;
start_user_mode(init->saved_regs.rip, init->saved_regs.rsp, init->p4_paddr);
}
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