.gitignore

@@ -1,3 +0,0 @@
-build/
-*.o
-*.elf

Makefile

@@ -1,20 +1,36 @@
+CROSS_COMPILE = arm-none-eabi-
+AS = $(CROSS_COMPILE)as
+CC = $(CROSS_COMPILE)gcc
+LD = $(CROSS_COMPILE)ld
+OBJCOPY = $(CROSS_COMPILE)objcopy
 
-CC=aarch64-linux-gnu-gcc
+CFLAGS = -Wall -mcpu=arm926ej-s -nostdlib -ffreestanding -I.
-LD=aarch64-linux-gnu-ld
-OBJCOPY=aarch64-linux-gnu-objcopy
 
-CFLAGS=-ffreestanding -O2 -nostdlib -Wall
+.SUFFIXES: .s .o .c
-LDFLAGS=-T link.ld
 
-OBJS=startup.o kernel_main.o uart.o scheduler.o smp.o vfs.o shell.o emmc.o mmc_cmds.o profiler.o proc.o virtio_net_dma.o
+%.o:    %.c
-
-all: kernel.elf
-
-%.o: %.c
 	$(CC) $(CFLAGS) -c $< -o $@
 
-kernel.elf: $(OBJS)
+%.o:    %.s
-	$(LD) $(LDFLAGS) -o $@ $(OBJS)
+	$(AS) -mcpu=arm926ej-s $< -o $@
+
+ASM_S_FILES = $(wildcard system/asm/*.s)
+ASM_O_FILES = $(ASM_S_FILES:.s=.o)
+
+CFILES = $(wildcard devices/*.c) $(wildcard devices/*/*.c) $(wildcard system/*.c) $(wildcard system/*/*.c)
+COFILES  = $(CFILES:.c=.o)
+OFILES = $(ASM_O_FILES) $(COFILES)
+
+all: kernel.bin
+
+kernel.elf: ${OFILES}
+	$(LD) -T boot.ld -o $@ $^
+
+kernel.bin: kernel.elf
+	$(OBJCOPY) -O binary $< $@
 
 clean:
-	rm -f *.o kernel.elf
+	rm -f *.o */*.o */*/*.o *.elf *.bin
+	
+run: kernel.bin
+	qemu-system-arm -M versatilepb -m 128M -nographic -kernel kernel.bin

README.md

@@ -1,27 +1,63 @@
+# MiniOS Kernel (ARMv7)
 
-# MiniOS
+This is a minimal bare-metal ARM kernel project built for educational and prototyping purposes.  
+It includes multitasking, a UART shell, a simple task scheduler, and IRQ handling.  
+Tested and compatible with **Windows 10** using `arm-none-eabi-gcc` and QEMU.
 
-MiniOS is a simple educational operating system designed for ARM64 (QEMU and Luckfox Lyra B M).  
+---
-It includes:
 
-- Preemptive multitasking with SMP
+## Features
-- UART console with shell
-- MMU and memory protection
-- IPC and basic VFS with /proc
-- Profiler and task inspector
-- Networking (VirtIO + UDP)
-- eMMC boot support
-- ELF loader
 
-## Build
+- ARMv7 Bootloader (`boot.s`, `boot.ld`)
+- UART driver (`uart.c`, `uart.h`)
+- Task manager with real context switching (`task.c`, `switch.s`)
+- Round-robin scheduler triggered by timer IRQ (`irq.s`)
+- Interactive shell via UART (`shell.c`)
+  - Supported commands:
+    - `ps` – list tasks
+    - `echo` – simple message
+    - `halt` – stop execution
+
+---
+
+## Requirements
+
+- **Windows 10**
+- [Git Bash](https://git-scm.com/download/win)
+- [GCC ARM Embedded Toolchain](https://developer.arm.com/downloads/-/gnu-rm)
+- [QEMU for Windows 64-bit](https://qemu.weilnetz.de/w64/)
+
+---
+
+## How to Build and Run
 
 ```bash
 make
+qemu-system-arm -M versatilepb -m 128M -nographic -kernel kernel.bin
 ```
 
-## Boot on Luckfox
+Once running, you'll see:
 
-```bash
-load mmc 0:1 0x40200000 kernel.elf
-bootelf 0x40200000
 ```
+MiniOS Kernel Booted
+MiniOS Shell>
+```
+
+Type one of the supported commands (`ps`, `echo`, `halt`).
+
+---
+
+## Next Steps (Optional)
+
+- Virtual File System (VFS)
+- `ls`, `cat`, `cd` shell commands
+- ELF binary loader
+- FAT32 filesystem support
+- Advanced multitasking with priorities
+
+---
+
+## Author
+
+Built by Georgiana using ARM bare-metal architecture.  
+Powered by QEMU and the GNU ARM Toolchain.

boot.ld

@@ -0,0 +1,20 @@
+ENTRY(_start)
+
+SECTIONS {
+    . = 0x8000;
+
+    .text : {
+        *(.text)
+    }
+
+    .data : {
+        *(.data)
+    }
+
+    .bss : {
+        *(.bss COMMON)
+    }
+
+    . = ALIGN(8);
+    stack_top = . + 0x1000;
+}

boot/load_boot.sh

@@ -1,5 +0,0 @@
-
-#!/bin/sh
-echo "Loading kernel to 0x40200000..."
-load mmc 0:1 0x40200000 kernel.elf
-bootelf 0x40200000

devices/uart.c

@@ -0,0 +1,19 @@
+#include "uart.h"
+
+#define UART_BASE ((volatile char *)0x101f1000)
+
+void uart_init(void) {}
+
+void uart_write(const char *msg) {
+    while (*msg) {
+        *UART_BASE = *msg++;
+    }
+}
+
+void uart_putchar(char c) {
+    *UART_BASE = c;
+}
+
+char uart_getchar(void) {
+    return *UART_BASE;
+}

devices/uart.h

@@ -0,0 +1,9 @@
+#ifndef UART_H
+#define UART_H
+
+void uart_init(void);
+void uart_write(const char *msg);
+void uart_putchar(char c);
+char uart_getchar(void);
+
+#endif

src/elf.c

@@ -1,8 +0,0 @@
-#include "elf.h"
-#include "uart.h"
-
-int elf_load(const void *elf_data) {
-    uart_puts("[ELF] Loading ELF...\n");
-    // Stub - parse headers, map segments
-    return 0;
-}

src/elf.h

@@ -1,6 +0,0 @@
-#ifndef ELF_H
-#define ELF_H
-
-int elf_load(const void *elf_data);
-
-#endif

src/emmc.c

@@ -1,43 +0,0 @@
-
-#include "emmc.h"
-#include "uart.h"
-#include "mmio.h"
-#include "delay.h"
-
-#define EMMC_BASE 0x10005000
-#define EMMC_ARG2 (EMMC_BASE + 0x00)
-#define EMMC_BLKSZCNT (EMMC_BASE + 0x04)
-#define EMMC_CMDTM (EMMC_BASE + 0x08)
-#define EMMC_RESP0 (EMMC_BASE + 0x0C)
-#define EMMC_DATA (EMMC_BASE + 0x20)
-#define EMMC_STATUS (EMMC_BASE + 0x24)
-
-void emmc_init(void) {
-    uart_print("[emmc] Init sequence...\n");
-    mmio_write(EMMC_CMDTM, 0x00000000); // Reset command
-    delay(1000);
-    uart_print("[emmc] Init done\n");
-}
-
-int emmc_read_block(uint32_t lba, uint8_t *buffer) {
-    mmio_write(EMMC_ARG2, lba);
-    mmio_write(EMMC_BLKSZCNT, (1 << 16) | 512); // 1 block
-    mmio_write(EMMC_CMDTM, 0x11200010); // CMD17 read single
-
-    while (mmio_read(EMMC_STATUS) & 0x2); // wait for ready
-
-    for (int i = 0; i < 128; i++) {
-        ((uint32_t*)buffer)[i] = mmio_read(EMMC_DATA);
-    }
-
-    return 0;
-}
-
-int emmc_boot(void) {
-    uart_print("[emmc] Booting...\n");
-    uint8_t *image = (uint8_t *)0x8000000;
-    emmc_read_block(2048, image); // Read first boot block
-    void (*entry)(void) = (void (*)(void))(image);
-    entry();
-    return 0;
-}

src/emmc.h

@@ -1,11 +0,0 @@
-
-#ifndef EMMC_H
-#define EMMC_H
-
-#include <stdint.h>
-
-void emmc_init(void);
-int emmc_read_block(uint32_t lba, uint8_t *buffer);
-int emmc_boot(void);
-
-#endif

src/ipc.c

@@ -1,38 +0,0 @@
-
-#include "ipc.h"
-#include "scheduler.h"
-#include <string.h>
-
-#define MAX_MSGS 8
-#define MAX_TASKS 16
-
-typedef struct {
-    ipc_msg_t queue[MAX_MSGS];
-    int head, tail, count;
-} ipc_queue_t;
-
-static ipc_queue_t ipc_queues[MAX_TASKS];
-
-void ipc_init(void) {
-    memset(ipc_queues, 0, sizeof(ipc_queues));
-}
-
-int ipc_send(uint64_t to_id, ipc_msg_t msg) {
-    if (to_id >= MAX_TASKS) return -1;
-    ipc_queue_t *q = &ipc_queues[to_id];
-    if (q->count >= MAX_MSGS) return -2;
-    q->queue[q->tail] = msg;
-    q->tail = (q->tail + 1) % MAX_MSGS;
-    q->count++;
-    return 0;
-}
-
-int ipc_recv(ipc_msg_t *msg_out) {
-    uint64_t id = scheduler_get_current()->id;
-    ipc_queue_t *q = &ipc_queues[id];
-    if (q->count == 0) return -3;
-    *msg_out = q->queue[q->head];
-    q->head = (q->head + 1) % MAX_MSGS;
-    q->count--;
-    return 0;
-}

src/ipc.h

@@ -1,16 +0,0 @@
-
-#ifndef IPC_H
-#define IPC_H
-#include <stdint.h>
-
-typedef struct {
-    uint64_t from;
-    uint32_t type;
-    uint64_t data;
-} ipc_msg_t;
-
-int ipc_send(uint64_t to_task_id, ipc_msg_t msg);
-int ipc_recv(ipc_msg_t *msg_out);
-void ipc_init(void);
-
-#endif

src/kernel_main.c

@@ -1,13 +0,0 @@
-
-#include "uart.h"
-#include "smp.h"
-#include "scheduler.h"
-
-void kernel_main(void) {
-    uart_init();
-    smp_init();
-    scheduler_init();
-    while (1) {
-        scheduler_schedule();
-    }
-}

src/mmc_cmds.c

@@ -1,9 +0,0 @@
-
-#include <stdint.h>
-
-// Placeholder for MMC commands implementation
-// To be implemented depending on hardware or simulation platform
-
-int mmc_send_cmd(uint32_t cmd, uint32_t arg) {
-    return 0;
-}

src/mmu.c

@@ -1,24 +0,0 @@
-#include <stdint.h>
-
-#define PAGE_SIZE       4096
-#define PAGE_TABLE_SIZE 4096
-#define MAIR_VALUE      0xFF
-
-static uint64_t __attribute__((aligned(PAGE_SIZE))) l1_table[512];
-
-void mmu_init(void) {
-    for (int i = 0; i < 512; i++) {
-        l1_table[i] = (i << 30) | (0b11 << 0) | (0b01 << 2);
-    }
-
-    asm volatile("msr mair_el1, %0" :: "r"(MAIR_VALUE));
-    uint64_t tcr = (16ULL << 0) | (16ULL << 16);
-    asm volatile("msr tcr_el1, %0" :: "r"(tcr));
-    uint64_t ttbr = (uint64_t)l1_table;
-    asm volatile("msr ttbr0_el1, %0" :: "r"(ttbr));
-    uint64_t sctlr;
-    asm volatile("mrs %0, sctlr_el1" : "=r"(sctlr));
-    sctlr |= (1 << 0) | (1 << 2) | (1 << 12);
-    asm volatile("msr sctlr_el1, %0" :: "r"(sctlr));
-    asm volatile("isb");
-}

src/mmu.h

@@ -1,6 +0,0 @@
-#ifndef MMU_H
-#define MMU_H
-
-void mmu_init(void);
-
-#endif

src/proc.c

@@ -1,18 +0,0 @@
-
-#include "uart.h"
-#include "scheduler.h"
-#include "profiler.h"
-
-void proc_uptime(void) {
-    extern int global_ticks;
-    uart_print("Uptime: ");
-    uart_print_int(global_ticks / 100);
-    uart_print(" seconds\n");
-}
-
-void proc_meminfo(void) {
-    extern int free_pages;
-    uart_print("Free memory pages: ");
-    uart_print_int(free_pages);
-    uart_print("\n");
-}

src/profiler.c

@@ -1,28 +0,0 @@
-
-#include "profiler.h"
-#include "uart.h"
-
-#define MAX_TASKS 16
-static int task_ticks[MAX_TASKS];
-
-void profiler_init(void) {
-    for (int i = 0; i < MAX_TASKS; i++) task_ticks[i] = 0;
-}
-
-void profiler_tick(void) {
-    extern int current_task_id;
-    task_ticks[current_task_id]++;
-}
-
-void profiler_report(void) {
-    uart_print("CPU Time per Task:\n");
-    for (int i = 0; i < MAX_TASKS; i++) {
-        if (task_ticks[i]) {
-            uart_print("Task ");
-            uart_print_int(i);
-            uart_print(": ");
-            uart_print_int(task_ticks[i]);
-            uart_print(" ticks\n");
-        }
-    }
-}

src/profiler.h

@@ -1,9 +0,0 @@
-
-#ifndef PROFILER_H
-#define PROFILER_H
-
-void profiler_init(void);
-void profiler_tick(void);
-void profiler_report(void);
-
-#endif

src/scheduler.c

@@ -1,30 +0,0 @@
-
-#include "scheduler.h"
-#include <string.h>
-
-#define MAX_TASKS 16
-static task_t tasks[MAX_TASKS];
-static int task_count = 0;
-static task_t *current = NULL;
-
-void scheduler_init(void) {
-    memset(tasks, 0, sizeof(tasks));
-    task_count = 0;
-    current = NULL;
-}
-
-void scheduler_add(task_t *t) {
-    if (task_count < MAX_TASKS) {
-        tasks[task_count++] = *t;
-    }
-}
-
-task_t *scheduler_get_current(void) {
-    return current;
-}
-
-void scheduler_schedule(void) {
-    static int i = 0;
-    current = &tasks[i];
-    i = (i + 1) % task_count;
-}

src/scheduler.h

@@ -1,17 +0,0 @@
-
-#ifndef SCHEDULER_H
-#define SCHEDULER_H
-
-typedef struct task {
-    int id;
-    int state;
-    void *stack;
-    void *stack_top;
-} task_t;
-
-void scheduler_init(void);
-void scheduler_add(task_t *t);
-void scheduler_schedule(void);
-task_t *scheduler_get_current(void);
-
-#endif

src/shell.c

@@ -1,38 +0,0 @@
-
-#include "uart.h"
-#include "vfs.h"
-#include "scheduler.h"
-#include "proc.h"
-
-void shell_loop(void) {
-    char buf[128];
-    while (1) {
-        uart_print("> ");
-        int i = 0;
-        while (1) {
-            char c = uart_getc();
-            if (c == '\r' || c == '\n') break;
-            if (i < 127) buf[i++] = c;
-            uart_putc(c);
-        }
-        buf[i] = 0;
-        uart_print("\n");
-
-        if (strcmp(buf, "ps") == 0) {
-            extern void scheduler_list_tasks(void);
-            scheduler_list_tasks();
-        } else if (strcmp(buf, "uptime") == 0) {
-            proc_uptime();
-        } else if (strcmp(buf, "meminfo") == 0) {
-            proc_meminfo();
-        } else if (strncmp(buf, "cat ", 4) == 0) {
-            const char *data = vfs_read(buf + 4);
-            if (data)
-                uart_print(data);
-            else
-                uart_print("File not found\n");
-        } else {
-            uart_print("Unknown command\n");
-        }
-    }
-}

src/smp.c

@@ -1,26 +0,0 @@
-
-#include "uart.h"
-
-volatile int core_ready[4];
-
-int get_core_id(void) {
-    uint64_t mpidr;
-    asm volatile("mrs %0, mpidr_el1" : "=r"(mpidr));
-    return mpidr & 0b11;
-}
-
-void core_entry(void) {
-    int cid = get_core_id();
-    uart_puts("Core ");
-    uart_putc('0' + cid);
-    uart_puts(" ready\n");
-    core_ready[cid] = 1;
-    while (1);
-}
-
-void smp_init(void) {
-    for (int i = 1; i < 4; i++) {
-        *(volatile uint64_t *)(0x4000008 + i * 8) = (uint64_t)core_entry;
-        asm volatile("sev");
-    }
-}

src/startup.s

@@ -1,6 +0,0 @@
-
-.section .text
-.global _start
-_start:
-    bl kernel_main
-    b .

src/switch.S

@@ -1,26 +0,0 @@
-
-.global context_switch
-.type context_switch, %function
-
-context_switch:
-    // Save callee-saved registers
-    stp x19, x20, [x0]
-    stp x21, x22, [x0, #16]
-    stp x23, x24, [x0, #32]
-    stp x25, x26, [x0, #48]
-    stp x27, x28, [x0, #64]
-    str x29, [x0, #80]
-    str x30, [x0, #88]
-    str sp, [x0, #96]
-
-    // Load new task context
-    ldp x19, x20, [x1]
-    ldp x21, x22, [x1, #16]
-    ldp x23, x24, [x1, #32]
-    ldp x25, x26, [x1, #48]
-    ldp x27, x28, [x1, #64]
-    ldr x29, [x1, #80]
-    ldr x30, [x1, #88]
-    ldr sp, [x1, #96]
-
-    ret

src/task.c

@@ -1,32 +0,0 @@
-
-#include "scheduler.h"
-#include "uart.h"
-#include <stdlib.h>
-#include <string.h>
-
-#define MAX_TASKS 16
-static task_t tasks[MAX_TASKS];
-static int task_count = 0;
-static task_t *current = NULL;
-
-void scheduler_init(void) {
-    memset(tasks, 0, sizeof(tasks));
-    task_count = 0;
-    current = NULL;
-}
-
-void scheduler_add(task_t *t) {
-    if (task_count < MAX_TASKS) {
-        tasks[task_count++] = *t;
-    }
-}
-
-task_t *scheduler_get_current(void) {
-    return current;
-}
-
-void scheduler_schedule(void) {
-    static int i = 0;
-    current = &tasks[i];
-    i = (i + 1) % task_count;
-}

src/uart.c

@@ -1,35 +0,0 @@
-
-#include <stdint.h>
-
-#define UART0_BASE 0x09000000
-#define UARTFR (*(volatile uint32_t *)(UART0_BASE + 0x18))
-#define UARTDR (*(volatile uint32_t *)(UART0_BASE + 0x00))
-
-void uart_init(void) {}
-
-void uart_putc(char c) {
-    while (UARTFR & (1 << 5));
-    UARTDR = c;
-}
-
-void uart_puts(const char *s) {
-    while (*s) uart_putc(*s++);
-}
-
-void uart_print(const char *s) {
-    uart_puts(s);
-}
-
-void uart_print_int(int x) {
-    char buf[16];
-    int i = 0;
-    if (x == 0) {
-        uart_putc('0');
-        return;
-    }
-    while (x > 0) {
-        buf[i++] = '0' + (x % 10);
-        x /= 10;
-    }
-    while (i--) uart_putc(buf[i]);
-}

src/uart.h

@@ -1,11 +0,0 @@
-
-#ifndef UART_H
-#define UART_H
-
-void uart_init(void);
-void uart_putc(char c);
-void uart_puts(const char *s);
-void uart_print(const char *s);
-void uart_print_int(int x);
-
-#endif

src/usb.c

@@ -1,12 +0,0 @@
-#include "usb.h"
-#include "uart.h"
-
-void usb_init(void) {
-    uart_puts("[USB] Initializing USB Host...\n");
-    // Placeholder logic - real implementation would probe EHCI/OHCI/XHCI
-}
-
-int usb_read_bulk(int device, void *buffer, int length) {
-    uart_puts("[USB] Reading bulk data...\n");
-    return -1; // Not implemented
-}

src/usb.h

@@ -1,7 +0,0 @@
-#ifndef USB_H
-#define USB_H
-
-void usb_init(void);
-int usb_read_bulk(int device, void *buffer, int length);
-
-#endif

src/vfs.c

@@ -1,29 +0,0 @@
-
-#include "vfs.h"
-#include "uart.h"
-#include <string.h>
-#include <stdbool.h>
-
-static vfs_file_t files[] = {
-    { "/dev/info.txt", "MiniOS v1.0 - Built July 2025\n" },
-    { "/proc/version", "MiniOS kernel 1.0\n" },
-    { NULL, NULL }
-};
-
-void vfs_init(void) {}
-
-const char *vfs_read(const char *path) {
-    for (int i = 0; files[i].path; i++) {
-        if (strcmp(files[i].path, path) == 0)
-            return files[i].content;
-    }
-    return NULL;
-}
-
-void vfs_list(const char *prefix) {
-    size_t len = strlen(prefix);
-    for (int i = 0; files[i].path; i++) {
-        if (strncmp(files[i].path, prefix, len) == 0)
-            uart_puts(files[i].path + len + 1), uart_puts("\n");
-    }
-}

src/vfs.h

@@ -1,14 +0,0 @@
-
-#ifndef VFS_H
-#define VFS_H
-
-typedef struct vfs_file {
-    const char *path;
-    const char *content;
-} vfs_file_t;
-
-const char *vfs_read(const char *path);
-void vfs_list(const char *prefix);
-void vfs_init(void);
-
-#endif

src/virtio_net_dma.c

@@ -1,46 +0,0 @@
-
-#include "uart.h"
-#include "pmm.h"
-#include <stdint.h>
-#include <string.h>
-
-#define VIRTIO_MMIO_BASE 0x10001000
-#define VIRTIO_NET_Q_TX 1
-
-typedef struct {
-    uint64_t addr;
-    uint32_t len;
-    uint16_t flags;
-    uint16_t next;
-} __attribute__((packed)) virtq_desc_t;
-
-typedef struct {
-    uint16_t flags;
-    uint16_t idx;
-    struct {
-        uint16_t id;
-        uint16_t len;
-    } ring[8];
-} __attribute__((packed)) virtq_used_t;
-
-static void *desc_area;
-
-void virtio_net_dma_send(const void *data, int len) {
-    volatile uint32_t *mmio = (volatile uint32_t *)VIRTIO_MMIO_BASE;
-    virtq_desc_t *desc = (virtq_desc_t *)desc_area;
-
-    void *packet = pmm_alloc_page();
-    memcpy(packet, data, len);
-
-    desc[0].addr = (uint64_t)(uintptr_t)packet;
-    desc[0].len = len;
-    desc[0].flags = 0;
-    desc[0].next = 0;
-
-    virtq_used_t *used = (virtq_used_t *)((uint8_t *)desc_area + 4096);
-    used->ring[0].id = 0;
-    used->ring[0].len = len;
-    used->idx++;
-
-    mmio[0x070 / 4] |= 0x4; // notify
-}