Splash

Makefile

@@ -12,13 +12,13 @@ CC_PROBLEMATIC_FLAGS=-Wno-unused-parameter -Wno-unused-variable
 LD := x86_64-elf-ld
 
 $(ELFFILE): $(BUILDDIR) $(OBJFILES)
-	nasm -f elf64 src/idt/idt.S -o $(BUILDDIR)/idt_stub.o
+	nasm -f elf64 src/arch/x86/idt.S -o $(BUILDDIR)/idt_stub.o
 	$(LD) -o $(ELFFILE) -T linker.ld $(OBJFILES) $(BUILDDIR)/idt_stub.o
 	# Get the symbols for debugging
 	nm -n $(ELFFILE) | awk '$$2 ~ /[TtDdBbRr]/ {print $$1, $$3}' > symbols.map
 	python3 symbols.py
 	nasm -f elf64 symbols.S -o $(BUILDDIR)/symbols.o
-	$(LD) -o $(ELFFILE) -T linker.ld $(OBJFILES) $(BUILDDIR)/idt_stub.o
+	$(LD) -o $(ELFFILE) -T linker.ld $(OBJFILES) $(BUILDDIR)/idt_stub.o $(BUILDDIR)/symbols.o
 
 $(BUILDDIR):
 	@mkdir -p $(BUILDDIR)

include/arch/x86.h

@@ -1,14 +1,17 @@
-/*
+#ifndef X86_H
- * @author  xamidev <xamidev@riseup.net>
+#define X86_H
- * @brief   Interrupt Descriptor Table setup and dispatching
- * @license GPL-3.0-only
- */
-
-#ifndef IDT_H
-#define IDT_H
 
+#include <stdbool.h>
 #include <stdint.h>
 
+uint64_t rdmsr(uint32_t msr);
+void cpuid(uint32_t leaf, uint32_t* eax, uint32_t* ebx, uint32_t* ecx, uint32_t* edx);
+void wrmsr(uint32_t msr, uint64_t value);
+bool x86_has_msr();
+void x86_arch_init();
+
+/* Interrupt Descriptor Table */
+
 void idt_init(void);
 
 struct interrupt_descriptor {

include/config.h

@@ -11,7 +11,14 @@
 #define PEPPEROS_VERSION_MAJOR "0"
 #define PEPPEROS_VERSION_MINOR "0"
 #define PEPPEROS_VERSION_PATCH "58"
-#define PEPPEROS_SPLASH "\x1b[38;5;196mPepperOS\x1b[0m version \x1b[38;5;220m"PEPPEROS_VERSION_MAJOR"."PEPPEROS_VERSION_MINOR"."PEPPEROS_VERSION_PATCH"\x1b[0m built on \x1b[38;5;40m"__DATE__" "__TIME__"\x1b[0m\n"
+#define PEPPEROS_SPLASH \
+"\x1b[38;5;196m                                      \x1b[38;5;231m____  _____\r\n\x1b[0m"\
+"\x1b[38;5;196m    ____  ___  ____  ____  ___  _____\x1b[38;5;231m/ __ \\/ ___/\r\n\x1b[0m"\
+"\x1b[38;5;196m   / __ \\/ _ \\/ __ \\/ __ \\/ _ \\/ ___\x1b[38;5;231m/ / / /\\__ \\ \r\n\x1b[0m"\
+"\x1b[38;5;196m  / /_/ /  __/ /_/ / /_/ /  __/ /  \x1b[38;5;231m/ /_/ /___/ / \r\n\x1b[0m"\
+"\x1b[38;5;196m / .___/\\___/ .___/ .___/\\___/_/   \x1b[38;5;231m\\____//____/  \r\n\x1b[0m"\
+"\x1b[38;5;196m/_/        /_/   /_/                             \r\n\x1b[0m"\
+"     --- version \x1b[38;5;220m"PEPPEROS_VERSION_MAJOR"."PEPPEROS_VERSION_MINOR"."PEPPEROS_VERSION_PATCH"\x1b[0m built on \x1b[38;5;40m"__DATE__" "__TIME__"\x1b[0m\r\n"
 
 /* process */
 #define PROCESS_NAME_MAX 64
@@ -31,7 +38,7 @@
 #define KERNEL_IDT_ENTRIES 33
 
 /* paging */
-#define PAGING_MAX_PHYS 0x100000000
+#define PAGING_MAX_PHYS 0x200000000
 
 /* heap */
 #define KHEAP_SIZE (32*1024*1024)

include/io/term/term.h

@@ -8,8 +8,8 @@
 #define TERM_H
 
 void kputs(const char* str);
-void _putchar(char character);
 void term_init(void);
 int printf(const char* fmt, ...);
+void internal_putc(int c, void *_);
 
 #endif

include/kernel.h

@@ -17,7 +17,7 @@ enum ErrorCodes {
 
 #include <io/serial/serial.h>
 #include <io/term/term.h>
-#include <idt/idt.h>
+#include <arch/x86.h>
 #include <stdbool.h>
 
 extern volatile uint64_t ticks;

src/arch/x86/cpuid.c

@@ -0,0 +1,21 @@
+/*
+ * @author  xamidev <xamidev@riseup.net>
+ * @brief   x86 CPU identification
+ * @license GPL-3.0-only
+ */
+
+#include <stdint.h>
+#include <stddef.h>
+
+/*
+ * cpuid - Wrapper for CPUID instruction
+ * @leaf: Requested leaf (input EAX)
+ * @eax: EAX register value (output)
+ * @ebx: EBX register value (output)
+ * @ecx: ECX register value (output)
+ * @edx: EDX register value (output)
+*/
+void cpuid(uint32_t leaf, uint32_t* eax, uint32_t* ebx, uint32_t* ecx, uint32_t* edx)
+{
+    __asm__ volatile("cpuid" : "=a"(*eax), "=b"(*ebx), "=c"(*ecx), "=d"(*edx) : "a"(leaf));
+}

src/arch/x86/idt.c

@@ -4,7 +4,7 @@
  * @license GPL-3.0-only
  */
 
-#include <idt/idt.h>
+#include <arch/x86.h>
 #include <stdint.h>
 #include <stddef.h>
 #include <io/serial/serial.h>
@@ -258,7 +258,7 @@ struct cpu_status_t* interrupt_dispatch(struct cpu_status_t* context)
 
         case 33: // Keyboard Interrupt
             keyboard_handler();
-            //process_create("keyboard-initiated", kbdproc_main, NULL); // DEBUG
+            process_create("keyboard-initiated", kbdproc_main, NULL); // DEBUG
             outb(0x20, 0x20);
             break;
 

src/arch/x86/init.c

@@ -0,0 +1,46 @@
+/*
+ * @author  xamidev <xamidev@riseup.net>
+ * @brief   x86 architecture-dependant initialization
+ * @license GPL-3.0-only
+ */
+
+#include <mem/gdt.h>
+#include <stdint.h>
+#include <arch/x86.h>
+#include <kernel.h>
+
+/*
+ * x86_overwrite_pat - Set PAT to WC
+ *
+ * This function overwrites the 1st Page Attribute
+ * Table entry, to enable the Write-Combining property
+ * when we map memory regions later on.
+ * The framebuffer will be mapped with WC, which makes
+ * memory access significantly faster by using burst
+ * operations. 
+*/
+
+static void x86_overwrite_pat()
+{
+    uint64_t pat = rdmsr(0x277);
+    pat &= ~(0xFFULL << 8); // Clear PAT1
+    pat |= (0x01ULL << 8); // PAT1 = 0x01 (WC)
+    wrmsr(0x277, pat);
+}
+
+/*
+ * x86_arch_init - Initialize x86 CPU structures
+ *
+ * This function is responsible for overriding a PAT entry
+ * (to put the framebuffer area in WC mode) only.
+ *
+ * Later, all architecture-dependant init (GDT, IDT, TSS, ...)
+ * should be initialized here, and separate function pointers
+ * should be set up for each arch.
+ */
+void x86_arch_init()
+{
+    x86_overwrite_pat();
+    idt_init();
+    gdt_init();
+}

src/arch/x86/msr.c

@@ -0,0 +1,66 @@
+/*
+ * @author  xamidev <xamidev@riseup.net>
+ * @brief   x86 MSR C wrappers
+ * @description
+ * Wrapper functions to access Model Specific Registers
+ *
+ * @license GPL-3.0-only
+ */
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <arch/x86.h>
+
+/*
+ * rdmsr - Read from MSR
+ * @msr: model specific register number 
+ *
+ * Read a 64-bit word from a Model Specific Register.
+ * Wrapper for the "rdmsr" instruction. It originally
+ * outputs to two 32-bit registers (EDX:EAX), so the
+ * function does the job of uniting them as a 64-bit
+ * value for us.
+ *
+ * Return:
+ * <value> - value read from MSR
+ */
+uint64_t rdmsr(uint32_t msr)
+{
+    uint32_t low;
+    uint32_t high;
+
+    __asm__ volatile("rdmsr" : "=a"(low), "=d"(high) : "c"(msr));
+
+    return ((uint64_t)high << 32) | low;
+}
+
+/*
+ * wrmsr - Write to MSR
+ * @msr: model specific register number 
+ *
+ * Write a 64-bit value to a Model Specific Register.
+ */
+void wrmsr(uint32_t msr, uint64_t value)
+{
+    uint32_t low = (uint32_t)(value & 0xFFFFFFFF);
+    uint32_t high = (uint32_t)(value >> 32);
+
+    __asm__ volatile("wrmsr" : : "c"(msr), "a"(low), "d"(high) : "memory");
+}
+
+/*
+ * x86_has_msr - Test for MSR support
+ *
+ * Checks if CPU supports Model Specific Registers
+ * using CPUID.01h:EDX[bit 5].
+ *
+ * Return:
+ * true  - MSR are supported
+ * false - MSR are not supported 
+ */
+bool x86_has_msr()
+{
+    uint32_t eax, ebx, ecx, edx;
+    cpuid(1, &eax, &ebx, &ecx, &edx);
+    return (edx & (1 << 5)) != 0;
+}

src/debug/panic.c

@@ -5,7 +5,7 @@
  */
 
 #include <stddef.h>
-#include <idt/idt.h>
+#include <arch/x86.h>
 #include <io/serial/serial.h>
 #include <kernel.h>
 
@@ -36,27 +36,6 @@ void read_rflags(uint64_t rflags)
 		CHECK_BIT(rflags, 19) ? "VIF " : "", /*virtual interrupt flag*/
 		CHECK_BIT(rflags, 20) ? "VIP " : "", /*virtual interrupt pending*/
 		CHECK_BIT(rflags, 21) ? "ID " : ""); /*id flag*/
-
-	if (init.terminal) {
-		printf("\x1b[38;5;226m%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s\x1b[38;5;231m\r\n",
-			CHECK_BIT(rflags, 0) ? "CF " : "",
-			CHECK_BIT(rflags, 2) ? "PF " : "",
-			CHECK_BIT(rflags, 4) ? "AF " : "",
-			CHECK_BIT(rflags, 6) ? "ZF " : "",
-			CHECK_BIT(rflags, 7) ? "SF " : "",
-			CHECK_BIT(rflags, 8) ? "TF " : "",
-			CHECK_BIT(rflags, 9) ? "IF " : "",
-			CHECK_BIT(rflags, 10) ? "DF " : "",
-			CHECK_BIT(rflags, 11) ? "OF " : "",
-			(CHECK_BIT(rflags, 12) && CHECK_BIT(rflags, 13)) ? "IOPL3 " : "IOPL0 ",
-			CHECK_BIT(rflags, 14) ? "NT " : "",
-			CHECK_BIT(rflags, 16) ? "RF " : "",
-			CHECK_BIT(rflags, 17) ? "VM " : "",
-			CHECK_BIT(rflags, 18) ? "AC " : "",
-			CHECK_BIT(rflags, 19) ? "VIF " : "",
-			CHECK_BIT(rflags, 20) ? "VIP " : "",
-			CHECK_BIT(rflags, 21) ? "ID " : "");
-	}
 }
 
 /*

src/io/kbd/ps2.c

@@ -216,10 +216,10 @@ void keyboard_handler()
 
                     if (c) {
                         if (c == '\n') {
-                            _putchar('\r');
+                            internal_putc('\r', NULL);
                         }
-                        // Should probably have a keyboard buffer here... instead of this
+
-                        _putchar(c);
+                        internal_putc(c, NULL);
                         keyboard_putchar(c);
                     }
                 }

src/io/serial/serial.c

@@ -6,9 +6,13 @@
  
 #include <kernel.h>
 #include <io/serial/serial.h>
+#include <sched/spinlock.h>
 
 extern struct init_status init;
 
+extern int panic_count;
+struct spinlock_t serial_lock = {0};
+
 /*
  * outb - Writes a byte to a CPU port
  * @port: CPU port to write to
@@ -85,9 +89,15 @@ static int is_transmit_empty()
  */
 void skputc(char c)
 {
-    // TODO: Spinlock here (serial access)
+    if (panic_count == 0) {
+        spinlock_acquire(&serial_lock);
         while (!is_transmit_empty()); // wait for free spot
         outb(PORT, c);
+        spinlock_release(&serial_lock);
+    } else {
+        while (!is_transmit_empty());
+        outb(PORT, c);
+    }
 }
 
 /*

src/io/term/term.c

@@ -30,19 +30,10 @@ extern struct flanterm_context* ft_ctx;
 extern struct init_status init;
 
 struct spinlock_t term_lock = {0};
+struct spinlock_t printf_lock = {0};
 
 extern int panic_count;
 
-/*
- * _putchar - Writes a character to terminal (DEPRECATED)
- * @character: character to write
- */
-void _putchar(char character)
-{
-	// TODO: Spinlock here (terminal access)
-	flanterm_write(ft_ctx, &character, 1);
-}
-
 /*
  * internal_putc - Internal putchar function
  * @c: char to print
@@ -83,14 +74,26 @@ void internal_putc(int c, void *_)
  *
  * Return:
  * <ret> - number of characters sent to the callback
+ * %-1   - error
  */
 int printf(const char* fmt, ...)
 {
+    if (panic_count == 0) {
+        spinlock_acquire(&printf_lock);
+        va_list args;
+        va_start(args, fmt);
+        int ret = npf_vpprintf(internal_putc, NULL, fmt, args);
+        va_end(args);
+        spinlock_release(&printf_lock);
+        return ret;
+    } else {
         va_list args;
         va_start(args, fmt);
         int ret = npf_vpprintf(internal_putc, NULL, fmt, args);
         va_end(args);
         return ret;
+    }
+    return -1;
 }
 
 /*
@@ -103,30 +106,14 @@ void kputs(const char* str)
 {
 	size_t i=0;
 	while (str[i] != 0) {
-		_putchar(str[i]);
+		internal_putc(str[i], NULL);
 		i++;
 	}
-	_putchar('\r');
 }
 
 extern struct flanterm_context* ft_ctx;
 extern struct boot_context boot_ctx;
 
-/*
- * flanterm_free_wrapper - free() wrapper for Flanterm 
- * @ptr:  pointer to free
- * @size: amount of bytes to free
- *
- * This function exists solely because the Flanterm initialization
- * function only accepts a free() function with a size parameter,
- * and the default one doesn't have it.
- */
-void flanterm_free_wrapper(void* ptr, size_t size)
-{
-	(void)size;
-	kfree(ptr);
-}
-
 /*
  * term_init - Video output/terminal initialization
  *

src/kmain.c

@@ -4,6 +4,7 @@
  * @license GPL-3.0-only
  */
 
+#include "arch/x86.h"
 #include <stdbool.h>	
 #include <stddef.h>
 #include <limine.h>
@@ -11,7 +12,6 @@
 #include <io/serial/serial.h>
 #include <mem/gdt.h>
 #include <mem/utils.h>
-#include <idt/idt.h>
 #include <kernel.h>
 #include <time/timer.h>
 #include <io/kbd/ps2.h>
@@ -24,6 +24,7 @@
 #include <config.h>
 #include <io/term/flanterm.h>
 #include <io/term/flanterm_backends/fb.h>
+#include <arch/x86.h>
 
 // Limine version used
 __attribute__((used, section(".limine_requests")))
@@ -68,7 +69,7 @@ struct process_t* idle_proc;
 // Never gets executed although pedicel is scheduled?
 void pedicel_main(void* arg)
 {
-	printf("\n\nWelcome to PepperOS! Pedicel speaking.\r\nNothing left to do, let's go idle!\r\n");
+	printf("\n\n\rWelcome to PepperOS! Pedicel speaking.\r\nNothing left to do, let's go idle!\r\n");
 }
 
 void idle_main(void* arg)
@@ -111,26 +112,23 @@ void kmain()
 	serial_init();
 	timer_init();
 
+	x86_arch_init();
+
 	boot_mem_display();
 	pmm_init(boot_ctx);
 
-	// Remap kernel , HHDM and framebuffer
 	paging_init(boot_ctx);
 	kheap_init();
 
 	keyboard_init(FR);
 	
-	gdt_init();
-	idt_init();
-	
 	process_init();
 	idle_proc = process_create("idle", (void*)idle_main, 0);
-	struct process_t* pedicel = process_create("pedicel", (void*)pedicel_main, 0);
+	process_create("pedicel", (void*)pedicel_main, 0);
 	process_create("thing", thing_main, NULL);
-	process_display_list(processes_list);
 
 	scheduler_init();
 
-	kputs(PEPPEROS_SPLASH);
+	printf(PEPPEROS_SPLASH);
 	idle();
 }

src/mem/paging.c

@@ -173,9 +173,9 @@ void paging_init(struct boot_context boot_ctx)
         }
     }
 
-    // 4GB
+    // 8GB
     if (max_phys > PAGING_MAX_PHYS) {
-        DEBUG("WARNING: max_phys capped to 4GB (%x) (from max_phys=%p)", PAGING_MAX_PHYS, max_phys);
+        DEBUG("WARNING: max_phys capped to PAGING_MAX_PHYS (from max_phys=%p)", max_phys);
         max_phys = PAGING_MAX_PHYS;
     }
 
@@ -202,9 +202,9 @@ void paging_init(struct boot_context boot_ctx)
     uint64_t fb_size = fb->pitch * fb->height;
     uint64_t fb_pages = (fb_size + PAGE_SIZE-1)/PAGE_SIZE;
 
-    // Map the framebuffer (with cache-disable & write-through)
+    // Map the framebuffer (PWT set, and no PCD means PAT1 [Write-Combining] for this region)
     for (uint64_t i=0; i<fb_pages; i++) {
-        paging_map_page(kernel_pml4, fb_virt+i*PAGE_SIZE, fb_phys+i*PAGE_SIZE, PTE_WRITABLE | PTE_PCD | PTE_PWT);
+        paging_map_page(kernel_pml4, fb_virt+i*PAGE_SIZE, fb_phys+i*PAGE_SIZE, PTE_WRITABLE | PTE_PWT);
         page_count++;
     }
     DEBUG("Mapped %u pages for framebuffer", page_count);

src/mem/pmm.c

@@ -11,6 +11,7 @@ it will probably need to get some info from Limine,
 to see which pages are used by kernel/bootloader/mmio/fb etc.
 */
 
+#include "config.h"
 #include <mem/paging.h>
 #include <limine.h>
 #include <stddef.h>
@@ -24,42 +25,6 @@ First we'll have to discover the physical memory layout,
 and for that we can use a Limine request.
 */
 
-struct limine_memmap_entry* biggest_entry;
-
-/*
- * pmm_find_biggest_usable_region - Finding the biggest free memory region
- * @memmap: Limine memory map
- * @hhdm:   Limine HHDM offset
- *
- * This function uses the memory map provided by the bootloader
- * to find the single biggest free memory region we can use.
- */
-static void pmm_find_biggest_usable_region(struct limine_memmap_response* memmap, struct limine_hhdm_response* hhdm)
-{
-    // Max length of a usable memory region
-    uint64_t length_max = 0;
-    uint64_t offset = hhdm->offset;
-
-    DEBUG("Usable Memory:");
-    for (size_t i=0; i<memmap->entry_count; i++) {
-        struct limine_memmap_entry* entry = memmap->entries[i];
-
-        if (entry->type == LIMINE_MEMMAP_USABLE) {
-            DEBUG("0x%p-0x%p mapped at 0x%p-0x%p", entry->base, entry->base+entry->length,
-                        entry->base+offset, entry->base+entry->length+offset);
-            if (entry->length > length_max)
-            {
-                length_max = entry->length;
-                biggest_entry = entry;
-            }
-        }
-    }
-
-    DEBUG("Biggest usable memory region:");
-    DEBUG("0x%p-0x%p mapped at 0x%p-0x%p", biggest_entry->base, biggest_entry->base + biggest_entry->length,
-            biggest_entry->base+offset, biggest_entry->base+biggest_entry->length+offset);
-}
-
 // Offset from Higher Half Direct Map
 uint64_t hhdm_off;
 
@@ -99,19 +64,32 @@ void pmm_free(uintptr_t addr)
  * This function marks the biggest memory region as
  * free, so we can use it in pmm_alloc.
  */
-static void pmm_init_freelist()
+static void pmm_init_freelist(struct limine_memmap_response* memmap)
 {
-    // We simply call pmm_free() on each page that is marked USABLE
+    uint64_t total_pages = 0;
-    // in our big memory region.
+
-    uint64_t base = ALIGN_UP(biggest_entry->base, PAGE_SIZE);
+    for (size_t i=0; i<memmap->entry_count; i++) {
-    uint64_t end = ALIGN_DOWN(biggest_entry->base + biggest_entry->length, PAGE_SIZE);
+        struct limine_memmap_entry* entry = memmap->entries[i];
+
+        if (entry->type == LIMINE_MEMMAP_USABLE) {
+            uint64_t base = ALIGN_UP(entry->base, PAGE_SIZE);
+            uint64_t end = ALIGN_DOWN(entry->base + entry->length, PAGE_SIZE);
+
+            if (end > PAGING_MAX_PHYS) {
+                end = PAGING_MAX_PHYS;
+            }
+
+            // Region above PAGING_MAX_PHYS
+            if (base >= end) continue;
 
-    uint64_t page_count=0;
             for (uint64_t addr = base; addr < end; addr += PAGE_SIZE) {
                 pmm_free(addr);
-        page_count++;
+                total_pages++;
             }
-    DEBUG("%u frames in freelist, available for use (%u bytes)", page_count, page_count*PAGE_SIZE);
+        }
+    }
+
+    DEBUG("%u frames in freelist, %u bytes available (%u MB)", total_pages, total_pages*PAGE_SIZE, total_pages*PAGE_SIZE/1000000);
 }
 
 /*
@@ -124,9 +102,9 @@ static void pmm_init_freelist()
 void pmm_init(struct boot_context boot_ctx)
 {
     hhdm_off = boot_ctx.hhdm->offset;
-    pmm_find_biggest_usable_region(boot_ctx.mmap, boot_ctx.hhdm);
+    //pmm_find_biggest_usable_region(boot_ctx.mmap, boot_ctx.hhdm);
 
     // Now we have biggest USABLE region,
     // so to populate the free list we just iterate through it
-    pmm_init_freelist();
+    pmm_init_freelist(boot_ctx.mmap);
 }

src/sched/scheduler.c

@@ -49,7 +49,6 @@ struct cpu_status_t* scheduler_schedule(struct cpu_status_t* context)
     }
 
     current_process->context = context;
-    //current_process->status = READY;
 
     for (;;) {
         struct process_t* prev_process = current_process;
@@ -65,6 +64,9 @@ struct cpu_status_t* scheduler_schedule(struct cpu_status_t* context)
             return idle_proc->context;
         } else {
             current_process->status = RUNNING;
+/*             if (prev_process != current_process) {
+                DEBUG("Changed from {pid=%u, name=%s} to {pid=%u, name=%s}", prev_process->pid, prev_process->name, current_process->pid, current_process->name);
+            } */
             break;
         }
     }