From 9af5588c30c4126a2800aae1afcb0de2c373dc6c Mon Sep 17 00:00:00 2001 From: Benji Dial Date: Mon, 20 May 2024 17:40:47 -0400 Subject: rewrite application stuff in the kernel to support multitasking --- kernel/source/app-memory.cpp | 189 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 189 insertions(+) create mode 100644 kernel/source/app-memory.cpp (limited to 'kernel/source/app-memory.cpp') diff --git a/kernel/source/app-memory.cpp b/kernel/source/app-memory.cpp new file mode 100644 index 0000000..cca1359 --- /dev/null +++ b/kernel/source/app-memory.cpp @@ -0,0 +1,189 @@ +#include +#include +#include + +namespace hilbert::kernel { + + app_memory::app_memory() { + + uint64_t p3_paddr; + paging::map_new_kernel_page(p3, p3_paddr); + paging::map_new_kernel_page(p4, p4_paddr); + + for (int i = 0; i < 512; ++i) { + p4[i] = 0; + p3[i] = 0; + p2s[i] = 0; + p1s[i] = 0; + pram_pages_to_free_on_exit[i] = 0; + } + + p4[0] = paging::encode_pte(p3_paddr, true, true, true); + p4[511] = paging::kernel_p4e; + + } + + app_memory::~app_memory() { + + //first we see if the p2s exist + for (int p3i = 0; p3i < 512; ++p3i) + if (p3[p3i]) { + + //now we see if the p1s under this p2 exist + for (int p2i = 0; p2i < 512; ++p2i) + if (p2s[p3i][p2i]) { + + //we see if the pages under this p1 need to be freed + for (int p1i = 0; p1i < 512; ++p1i) + if (pram_pages_to_free_on_exit[p3i][p2i][p1i]) + paging::free_pram_page( + paging::pte_to_paddr(p1s[p3i][p2i][p1i])); + + //we free the p1 and the pram list + paging::free_pram_page(paging::pte_to_paddr(p2s[p3i][p2i])); + paging::unmap_kernel_page((uint64_t)p1s[p3i][p2i]); + delete[] pram_pages_to_free_on_exit[p3i][p2i]; + + } + + //free the p2, the p1 list, and the pram list list + paging::free_pram_page(paging::pte_to_paddr(p3[p3i])); + paging::unmap_kernel_page((uint64_t)p2s[p3i]); + delete[] p1s[p3i]; + delete[] pram_pages_to_free_on_exit[p3i]; + + } + + //finally, we free the p3 and the p4 + paging::free_pram_page(paging::pte_to_paddr(p4[0])); + paging::unmap_kernel_page((uint64_t)p3); + paging::free_pram_page(p4_paddr); + paging::unmap_kernel_page((uint64_t)p4); + + } + + void app_memory::map_page(uint64_t vaddr, uint64_t paddr, + bool write, bool execute, bool free_pram_on_exit) { + + int p1i = (vaddr >> 12) & 511; + int p2i = (vaddr >> 21) & 511; + int p3i = (vaddr >> 30) & 511; + + if (p2s[p3i] == 0) { + uint64_t new_p2_paddr; + paging::map_new_kernel_page(p2s[p3i], new_p2_paddr); + p1s[p3i] = new v_page_table[512]; + pram_pages_to_free_on_exit[p3i] = new bool *[512]; + for (int i = 0; i < 512; ++i) { + p2s[p3i][i] = 0; + p1s[p3i][i] = 0; + pram_pages_to_free_on_exit[p3i][i] = 0; + } + p3[p3i] = paging::encode_pte(new_p2_paddr, true, true, true); + } + + if (p1s[p3i][p2i] == 0) { + uint64_t new_p1_paddr; + paging::map_new_kernel_page(p1s[p3i][p2i], new_p1_paddr); + pram_pages_to_free_on_exit[p3i][p2i] = new bool[512]; + for (int i = 0; i < 512; ++i) { + p1s[p3i][p2i][i] = 0; + pram_pages_to_free_on_exit[p3i][p2i][i] = false; + } + p2s[p3i][p2i] = paging::encode_pte(new_p1_paddr, true, true, true); + } + + p1s[p3i][p2i][p1i] = paging::encode_pte(paddr, true, write, execute); + pram_pages_to_free_on_exit[p3i][p2i][p1i] = free_pram_on_exit; + + } + + void app_memory::unmap_page(uint64_t vaddr) { + int p1i = (vaddr >> 12) & 511; + int p2i = (vaddr >> 21) & 511; + int p3i = (vaddr >> 30) & 511; + if (pram_pages_to_free_on_exit[p3i][p2i][p1i]) { + pram_pages_to_free_on_exit[p3i][p2i][p1i] = false; + paging::free_pram_page(paging::pte_to_paddr(p1s[p3i][p2i][p1i])); + } + p1s[p3i][p2i][p1i] = 0; + } + + bool app_memory::valid_to_read( + uint64_t vaddr_start, uint64_t vaddr_end, bool and_write) const { + if (vaddr_start > vaddr_end || vaddr_end > 0x8000000000) + return false; + vaddr_start = (vaddr_start / 4096) * 4096; + vaddr_end = (((vaddr_end - 1) / 4096) + 1) * 4096; + for (uint64_t vaddr = vaddr_start; vaddr < vaddr_end; ++vaddr) { + int p1i = (vaddr >> 12) & 511; + int p2i = (vaddr >> 21) & 511; + int p3i = (vaddr >> 30) & 511; + if (!p1s[p3i] || !p1s[p3i][p2i] || !(and_write + ? (p1s[p3i][p2i][p1i] & 0x1) : p1s[p3i][p2i][p1i])) + return false; + } + return true; + } + + uint64_t app_memory::get_free_vaddr_pages(uint64_t count) { + uint64_t vaddr = 0x1000; + uint64_t run = 0; + while (true) { + if (run == count) + return vaddr; + if (vaddr + (run + 1) * 4096 > 0x4000000000) + //TODO: handle out of virtual memory + panic(0x9af5e6); + if (valid_to_read(vaddr + run * 4096, vaddr + (run + 1) * 4096, false)) { + vaddr += (run + 1) * 4096; + run = 0; + } + else + ++run; + } + } + + uint64_t app_memory::map_new_stack() { + for (uint64_t base_vaddr = 0x4000000000; + base_vaddr < 0x8000000000; base_vaddr += 0x1000000) + if (!valid_to_read(base_vaddr + 4096, base_vaddr + 8192, false)) { + + for (uint64_t vaddr = base_vaddr + 4096; + vaddr < base_vaddr + 0x1000000; vaddr += 4096) { + + uint8_t *kvaddr; + uint64_t paddr; + paging::map_new_kernel_page(kvaddr, paddr); + for (int i = 0; i < 4096; ++i) + kvaddr[i] = 0; + paging::unmap_kernel_page(kvaddr); + map_page(vaddr, paddr, true, false, true); + + } + return base_vaddr + 0x1000000; + + } + //TODO: handle out of stacks + panic(0x9af5e6); + + } + + void app_memory::unmap_stack(uint64_t top) { + for (uint64_t vaddr = top - 0xfff000; vaddr < top; vaddr += 4096) + unmap_page(vaddr); + } + + uint64_t app_memory::count_mapped_vram_pages() const { + uint64_t count = 0; + for (int p3i = 0; p3i < 512; ++p3i) + if (p3[p3i]) + for (int p2i = 0; p2i < 512; ++p2i) + if (p2s[p3i][p2i]) + for (int p1i = 0; p1i < 512; ++p1i) + if (p1s[p3i][p2i][p1i]) + ++count; + return count; + } + +} -- cgit v1.2.3