Fixed bug in page counting for elf file loading. Added support for writeable segments...

diff --git a/kernel/src/kernel.cpp b/kernel/src/kernel.cpp
index a2cbd5891ff0bfdc3316fcb74bf516e6c4912bf1..3933a160f95087110d99277bf350056e3b4aafb1 100644 (file)
--- a/kernel/src/kernel.cpp
+++ b/kernel/src/kernel.cpp
@@ -194,30 +194,30 @@ extern "C" void kmain(unsigned long magic, os::phys_ptr<const multiboot2::info_s
                os::assert((std::uintptr_t(program_header.p_vaddr) & 0xFFF) == 0, "Program segment not 4KiB aligned.");
 
                // Allocate memory for segment:
-               std::size_t nb_pages = (program_header.p_memsz + 1023) / 1024;
+               std::size_t nb_pages = (program_header.p_memsz + 0x1000) / 0x1000;
                for (std::size_t i = 0; i < nb_pages; i++) {
                        const auto indices = os::paging::calc_page_table_indices(program_header.p_vaddr + i * 0x1000);
                        os::assert(indices.pml4e < 256, "Userspace program must be in the lower-half of virtual memory.");
                        if (PML4T.contents[indices.pml4e].P == 0) {
-                               PML4T.contents[indices.pml4e] = {.P = 1, .R_W = 0, .U_S = 1, .PWT = 0, .PCD = 0, .base_address = 0, .NX = 0};
+                               PML4T.contents[indices.pml4e] = {.P = 1, .R_W = 1, .U_S = 1, .PWT = 0, .PCD = 0, .base_address = 0, .NX = 0};
                                const auto PDPT_alloc = os::paging::page_allocator.allocate(1);
                                set_base_address(PML4T.contents[indices.pml4e], os::phys_ptr<os::paging::PDPT>(PDPT_alloc.ptr.get_phys_addr()));
                        }
                        os::paging::PDPT& PDPT = *get_base_address(PML4T.contents[indices.pml4e]);
                        if (PDPT.contents[indices.pdpe].non_page.P == 0) {
-                               PDPT.contents[indices.pdpe] = {.non_page = {.P = 1, .R_W = 0, .U_S = 1, .PWT = 0, .PCD = 0, .base_address = 0, .NX = 0}};
+                               PDPT.contents[indices.pdpe] = {.non_page = {.P = 1, .R_W = 1, .U_S = 1, .PWT = 0, .PCD = 0, .base_address = 0, .NX = 0}};
                                const auto PDT_alloc = os::paging::page_allocator.allocate(1);
                                set_base_address(PDPT.contents[indices.pdpe], os::phys_ptr<os::paging::PDT>(PDT_alloc.ptr.get_phys_addr()));
                        }
                        os::paging::PDT& PDT = *get_base_address(PDPT.contents[indices.pdpe]);
                        if (PDT.contents[indices.pde].non_page.P == 0) {
-                               PDT.contents[indices.pde] = {.non_page = {.P = 1, .R_W = 0, .U_S = 1, .PWT = 0, .PCD = 0, .base_address = 0, .NX = 0}};
+                               PDT.contents[indices.pde] = {.non_page = {.P = 1, .R_W = 1, .U_S = 1, .PWT = 0, .PCD = 0, .base_address = 0, .NX = 0}};
                                const auto PT_alloc = os::paging::page_allocator.allocate(1);
                                set_base_address(PDT.contents[indices.pde], os::phys_ptr<os::paging::PT>(PT_alloc.ptr.get_phys_addr()));
                        }
                        os::paging::PT& PT = *get_base_address(PDT.contents[indices.pde]);
                        if (PT.contents[indices.pe].P == 0) {
-                               PT.contents[indices.pe] = {.P = 1, .R_W = 0, .U_S = 1, .PWT = 0, .PCD = 0, .PAT = 0, .G = 0, .base_address = 0, .NX = 0};
+                               PT.contents[indices.pe] = {.P = 1, .R_W = (program_header.flags & 2) >> 1, .U_S = 1, .PWT = 0, .PCD = 0, .PAT = 0, .G = 0, .base_address = 0, .NX = 0};
                                const auto page_alloc = os::paging::page_allocator.allocate(1);
                                set_page_base_address(PT.contents[indices.pe], os::phys_ptr<os::paging::page>(page_alloc.ptr.get_phys_addr()));
                        }