started working on pmm and fixed printf doing weird things to the

numbers

9 files changed, 153 insertions, 26 deletions

diff --git a/.bochsrc b/.bochsrc
index 8cd280b..924ea32 100644
--- a/.bochsrc
+++ b/.bochsrc
@@ -3,13 +3,15 @@ boot: cdrom
 
 megs: 256
 
-display_library: sdl2
-#display_library: sdl2, options="gui_debug"
+#display_library: sdl2
+display_library: sdl2, options="gui_debug"
 
 vga: extension=vbe
 
 magic_break: enabled=1
 
-clock: sync=none, time0=local
+clock: sync=realtime, time0=local
 
 cpu: reset_on_triple_fault=0
+
+com1: enabled=1, mode=file, dev=misc/bochs.txt
\ No newline at end of file
diff --git a/kernel/arch/x86_64/limine.cpp b/kernel/arch/x86_64/limine.cpp
index 6d7984e..b592592 100644
--- a/kernel/arch/x86_64/limine.cpp
+++ b/kernel/arch/x86_64/limine.cpp
@@ -2,10 +2,11 @@
 #include <stddef.h>

 #include <stdio.h>

 #include <arch/x86_64/serial.h>

-#include "limine.h"

+#include <limine.h>

 #include "gdt.h"

 #include "idt.h"

 #include <framebuffer.h>

+#include <mm/pmm.h>

 

 namespace {

 __attribute__((used, section(".requests")))

@@ -22,6 +23,24 @@ volatile limine_framebuffer_request framebuffer_request = {
 }

 

 namespace {

+__attribute__((used, section(".requests")))

+volatile limine_memmap_request memmap_request = {

+    .id = LIMINE_MEMMAP_REQUEST,

+    .revision = 0,

+    .response = nullptr  

+};

+}

+

+namespace {

+__attribute__((used, section(".requests")))

+volatile limine_hhdm_request hhdm_request = {

+    .id = LIMINE_HHDM_REQUEST,

+    .revision = 0,

+    .response = nullptr  

+};

+}

+

+namespace {

 __attribute__((used, section(".requests_start_marker")))

 volatile LIMINE_REQUESTS_START_MARKER;

 

@@ -30,7 +49,7 @@ volatile LIMINE_REQUESTS_END_MARKER;
 }

 

 namespace {

-void hcf() {

+[[noreturn]] void hcf() {

     asm("cli");

     for (;;) {

         asm("hlt");

@@ -41,7 +60,7 @@ void hcf() {
 extern void (*__init_array[])();

 extern void (*__init_array_end[])();

 

-extern "C" void kernel_main();

+void kernel_main();

 

 extern "C" void _start() {

     asm("cli");

@@ -75,8 +94,12 @@ extern "C" void _start() {
         hcf();

     }

 

+    if (memmap_request.response == nullptr) {

+        hcf();

+    }

+

     // Fetch the first framebuffer.

-    limine_framebuffer *framebuffer = framebuffer_request.response->framebuffers[0];

+    limine_framebuffer* framebuffer = framebuffer_request.response->framebuffers[0];

 

     // Note: we assume the framebuffer model is RGB with 32-bit pixels.

     // for (size_t i = 0; i < 100; i++) {

@@ -84,11 +107,10 @@ extern "C" void _start() {
     //     fb_ptr[i * (framebuffer->pitch / 4) + i] = 0xffffff;

     // }

 

-    asm("xchgw %bx, %bx");

     fb_init((uint32_t*)framebuffer->address, framebuffer->width, framebuffer->height);

     draw_pixel(727, 727, 0x9528fd);

     draw_pixel(0, 0, 0xff0000);

-    draw_pixel(1919, 1079, 0x00ff00);

+    draw_pixel(framebuffer->width - 1, framebuffer->height - 1, 0x00ff00);

     // for (size_t i = 0; i < framebuffer->mode_count; i++) {

     //     printf("Mode %d\n", i);

     //     printf("Pitch %d\nWidth %d\nHeight %d\nbpp %d\nmem_model %d\n",

@@ -100,6 +122,17 @@ extern "C" void _start() {
     printf("Pitch %d\nWidth %d\nHeight %d\nbpp %d\nmem_model %d\n",

         framebuffer->pitch, framebuffer->width, framebuffer->height,

         framebuffer->bpp, framebuffer->memory_model);

+    

+    limine_memmap_response* memmap = memmap_request.response;

+    for (int i = 0; i < memmap->entry_count; i++) {

+        printf("base: %lx\nlength: %lx\ntype: %d\n\n", 

+        memmap->entries[i]->base, memmap->entries[i]->length, memmap->entries[i]->type);

+    }

+

+    // broken printf mirroring 64 bit values for some reason

+    //uint64_t tester = 0xFFFE0000000000AE + 1;

+    //printf("aaaa: %lx\n", tester);

+    pmm_init(memmap_request.response, hhdm_request.response->offset);

 

     kernel_main();

 

diff --git a/kernel/arch/x86_64/limine.h b/kernel/include/limine.h
index b4afb43..b4afb43 100644
--- a/kernel/arch/x86_64/limine.h
+++ b/kernel/include/limine.h
diff --git a/kernel/include/mm/pmm.h b/kernel/include/mm/pmm.h
new file mode 100644
index 0000000..bfe21c5
--- /dev/null
+++ b/kernel/include/mm/pmm.h
@@ -0,0 +1,27 @@
+#ifndef PMM_H
+#define PMM_H
+
+#include <stdint.h>
+#include <stddef.h>
+#include <limine.h>
+
+enum mm_type {
+    MEM_USABLE,
+    MEM_RESERVED
+};
+
+struct MMEntry {
+    uint64_t base;
+    uint64_t length;
+    mm_type type;
+};
+
+struct PBitmap {
+    uint64_t* addr;
+    size_t size;
+    MMEntry entry;
+};
+
+void pmm_init(limine_memmap_response* memmap, uint64_t hhdm_offset);
+
+#endif
\ No newline at end of file
diff --git a/kernel/kernel.cpp b/kernel/kernel.cpp
index a0394ea..e72500e 100644
--- a/kernel/kernel.cpp
+++ b/kernel/kernel.cpp
@@ -12,7 +12,7 @@ unsigned int _kernel_begin;
 unsigned int _kernel_end;

 

 

-extern "C" void kernel_main(void) {

+void kernel_main(void) {

     // Initialize terminal

     //terminal_initialize();

 

diff --git a/kernel/makefile b/kernel/makefile
index dfced86..030caaa 100644
--- a/kernel/makefile
+++ b/kernel/makefile
@@ -3,15 +3,16 @@
 CFLAGS := -ffreestanding -Wall -Wextra -g -std=gnu99 -O2 -Iinclude --sysroot=$(SYSROOT) \

 	-isystem="/usr/include"

 CXXFLAGS := -ffreestanding -Wall -Wextra -fno-exceptions -fno-rtti -g -O2 -Iinclude --sysroot=$(SYSROOT) \

-	-isystem="/usr/include"

+	-isystem="/usr/include" -std=gnu++20

 LDFLAGS := -T arch/$(ARCH)/linker.ld -ffreestanding -g -O2 -Iinclude --sysroot=$(SYSROOT) \

 	-isystem="/usr/include"

 ASMFLAGS :=

 

 ifeq ($(ARCH),x86_64)

-CFLAGS += -mno-red-zone -mcmodel=kernel -mno-sse -mno-sse2 -mno-mmx

-CXXFLAGS += -mno-red-zone -mcmodel=kernel -mno-sse -mno-sse2 -mno-mmx

-LDFLAGS += -mno-red-zone -mcmodel=kernel -mno-sse -mno-sse2 -mno-mmx

+CFLAGS += -mno-red-zone -mcmodel=kernel -mno-80387 -mno-sse -mno-sse2 -mno-mmx

+CXXFLAGS += -mno-red-zone -mcmodel=kernel -mno-80387 -mno-sse -mno-sse2 -mno-mmx

+LDFLAGS += -mno-red-zone -mcmodel=kernel -mno-80387 -mno-sse -mno-sse2 -mno-mmx \

+	-z max-page-size=0x1000

 ASMFLAGS += -felf64

 endif

 

@@ -75,4 +76,4 @@ install-headers: $(HEADERS)
 

 clean:

 	$(info [INFO] Cleaning)

-	$(RM) ${OBJS} $(DEPFILES) kernel.bin
\ No newline at end of file
+	$(RM) ${OBJS} $(DEPFILES) kernel.bin

diff --git a/kernel/mm/pmm.cpp b/kernel/mm/pmm.cpp
new file mode 100644
index 0000000..bd8f12c
--- /dev/null
+++ b/kernel/mm/pmm.cpp
@@ -0,0 +1,55 @@
+#include <mm/pmm.h>
+#include <stdio.h>
+
+PBitmap bitmap;
+
+// Finds the biggest chunk of memory
+static MMEntry find_mem_chunk(limine_memmap_response* memmap) {
+    uint64_t highestmem = 0;
+    size_t highestindex = 0;
+    limine_memmap_entry* entries = memmap->entries[0];
+    for (size_t i = 0; i < memmap->entry_count; i++) {
+        if (entries[i].type == LIMINE_MEMMAP_USABLE && entries[i].length > highestmem) {
+            highestmem = entries[i].length;
+            highestindex = i;
+        }
+    }
+
+    return MMEntry{
+        entries[highestindex].base,
+        entries[highestindex].length,
+        MEM_USABLE
+    };
+}
+
+void pmm_init(limine_memmap_response* memmap, uint64_t hhdm_offset) {
+    MMEntry mem_entry = find_mem_chunk(memmap);
+
+    // Round any numbers needed to 4K boudaries
+    //mem_entry.base += 4096 - (mem_entry.base % 4096);
+    mem_entry.length -= mem_entry.length % 4096;
+
+    // setup bitmap at the beginning of the chunk
+    bitmap.entry = mem_entry;
+    bitmap.addr = (uint64_t*)(bitmap.entry.base + hhdm_offset);
+    // divided by byte size since size is for iterating over the bitmap
+    bitmap.size = mem_entry.length / 4096 / sizeof(uint64_t);
+
+    printf("addr: %lx\nsize: %lx\n", (uint64_t)bitmap.addr, bitmap.size);
+    printf("hhdm offset: %lx\n", hhdm_offset);
+
+    // write test
+    for (size_t i = 0; i < 100; i++) {
+        bitmap.addr[i] = i;
+        //printf("value %d: %lx\n", i, bitmap.addr[i]);
+    }
+
+    // read test
+    for (size_t i = 0; i < bitmap.size; i++) {
+        //printf("value %d: %lx\n");
+    }
+}
+
+uint64_t get_phys_page() {
+
+}
\ No newline at end of file
diff --git a/libc/printf.c b/libc/printf.c
index 72a4749..0bb5506 100644
--- a/libc/printf.c
+++ b/libc/printf.c
@@ -37,10 +37,14 @@ static const char* itoa(unsigned int num, char* str, unsigned int base) {
 	}

 	

 	// reverse the string

-	for (int i = 0; i < cou; i++) {

-		char temp = str[i];

-		str[i] = str[cou - i - 1]; 

-		str[cou - 1] = temp;

+	size_t start = 0;

+	size_t end = cou - 1;

+	while (start < end) {

+		char temp = str[start];

+		str[start] = str[end];

+		str[end] = temp;

+		++start;

+		--end;

 	}

 

 	str[cou] = '\0';

@@ -49,7 +53,7 @@ static const char* itoa(unsigned int num, char* str, unsigned int base) {
 

 // have no idea if there's a better way to do this. for %lx

 static const char* itoa_u64(unsigned long long num, char* str, int base) {

-	int cou = 0; // nt

+	size_t cou = 0; // nt

 

     if (num == 0) { // 0

 		str[cou] = '0';

@@ -71,10 +75,14 @@ static const char* itoa_u64(unsigned long long num, char* str, int base) {
 	}

 	

 	// reverse the string

-	for (int i = 0; i < cou; i++) {

-		char temp = str[i];

-		str[i] = str[cou - i - 1]; 

-		str[cou - 1] = temp;

+	size_t start = 0;

+	size_t end = cou - 1;

+	while (start < end) {

+		char temp = str[start];

+		str[start] = str[end];

+		str[end] = temp;

+		++start;

+		--end;

 	}

 

 	str[cou] = '\0';

diff --git a/makefile b/makefile
index d8535bc..8717518 100644
--- a/makefile
+++ b/makefile
@@ -34,10 +34,11 @@ limine: build-all
         -no-emul-boot -boot-load-size 4 -boot-info-table \

         --efi-boot boot/limine/limine-uefi-cd.bin \

         -efi-boot-part --efi-boot-image --protective-msdos-label \

-        isodir -o emuos.iso

+        isodir -o $(OS_NAME).iso

+	limine bios-install $(OS_NAME).iso

 

 qemu: limine

-	$(QEMU) -no-shutdown -no-reboot --serial stdio -s -m 512 -hda $(OS_NAME).iso

+	$(QEMU) -no-shutdown -no-reboot --serial stdio -s -m 1024 -hda $(OS_NAME).iso

 

 install: install-headers install-libraries