311551158 lab2

Lab1/kernel code/README.md

@@ -0,0 +1,3 @@
+| Github Account | Student ID | Name          |
+|----------------|------------|---------------|
+|Hsu0208         | 311551158  | Wei Ling Hsu  |

start.S → Lab1/kernel code/start.S

@@ -9,7 +9,7 @@ _start:
     cbz     x1, 2f
     // cpu id > 0, stop
 1:  wfe
-    b       1b
+    b       1b // b uncinditional branch 1-label b- backward
 2:  // cpu id == 0
 
     // set stack before our code

Lab2/Makefile

@@ -0,0 +1,34 @@
+ARMGNU = aarch64-linux-gnu
+
+CFLAGS = -Wall -O2 -ffreestanding -nostdinc -nostdlib -nostartfiles
+ASMFLAGS = -Iinclude
+QEMUFLAGS = -M raspi3b -display none -serial null -serial pty
+
+BUILD_DIR = build
+SRC_DIR = src
+
+C_FILES = $(wildcard $(SRC_DIR)/*.c)
+ASM_FILES = $(wildcard $(SRC_DIR)/*.S)
+OBJ_FILES = $(C_FILES:$(SRC_DIR)/%.c=$(BUILD_DIR)/%.o)
+OBJ_FILES += $(ASM_FILES:$(SRC_DIR)/%.S=$(BUILD_DIR)/%.o)
+
+$(BUILD_DIR)/%.o: $(SRC_DIR)/%.c
+	mkdir -p $(@D)
+	$(ARMGNU)-gcc $(CFLAGS) -c $< -o $@
+
+$(BUILD_DIR)/%.o: $(SRC_DIR)/%.S
+	mkdir -p $(@D)
+	$(ARMGNU)-gcc $(ASMFLAGS) -c $< -o $@
+
+all: clean kernel8.img
+
+kernel8.img: $(SRC_DIR)/link.ld $(OBJ_FILES)
+	$(ARMGNU)-ld -T $(SRC_DIR)/link.ld -o $(BUILD_DIR)/kernel8.elf $(OBJ_FILES)
+	$(ARMGNU)-objcopy $(BUILD_DIR)/kernel8.elf -O binary kernel8.img
+
+clean:
+	rm -rf $(BUILD_DIR) *.img *.elf *.o
+
+qemu: kernel8.img
+	qemu-system-aarch64 -M raspi3b -kernel kernel8.img -serial null -serial stdio -display none -initrd initramfs.cpio
+

Lab2/bash_send_kernel.sh

@@ -0,0 +1,25 @@
+#!/bin/bash
+
+## rapspi -> bash send_kernel.sh
+## qemu   -> bash send_kernel.sh i
+
+## Construct the device path
+if [ $# -eq 0 ]; then
+    device="/dev/ttyUSB0"
+else
+    index="$1"
+    device="/dev/pts/$index"
+fi
+
+# Check if the device file exists
+if [ ! -c "$device" ]; then
+    echo "Device not found: $device"
+    exit 1
+fi
+
+# Change permissions of the device file
+echo chmod a+rw "$device"
+sudo chmod a+rw "$device"
+
+# Execute send_kernel.py with the appropriate argument
+python3 send_kernel.py $1

Lab2/bootloader/Makefile

@@ -0,0 +1,33 @@
+ARMGNU = aarch64-linux-gnu
+
+CFLAGS = -Wall -O2 -ffreestanding -nostdinc -nostdlib -nostartfiles
+ASMFLAGS = -Iinclude
+QEMUFLAGS = -M raspi3b -display none -serial null -serial pty
+
+BUILD_DIR = build
+SRC_DIR = src
+
+C_FILES = $(wildcard $(SRC_DIR)/*.c)
+ASM_FILES = $(wildcard $(SRC_DIR)/*.S)
+OBJ_FILES = $(C_FILES:$(SRC_DIR)/%.c=$(BUILD_DIR)/%.o)
+OBJ_FILES += $(ASM_FILES:$(SRC_DIR)/%.S=$(BUILD_DIR)/%.o)
+
+$(BUILD_DIR)/%.o: $(SRC_DIR)/%.c
+	mkdir -p $(@D)
+	$(ARMGNU)-gcc $(CFLAGS) -c $< -o $@
+
+$(BUILD_DIR)/%.o: $(SRC_DIR)/%.S
+	mkdir -p $(@D)
+	$(ARMGNU)-gcc $(ASMFLAGS) -c $< -o $@
+
+all: bootloader.img
+
+bootloader.img: $(SRC_DIR)/link.ld $(OBJ_FILES)
+	$(ARMGNU)-ld -T $(SRC_DIR)/link.ld -o $(BUILD_DIR)/bootloader.elf $(OBJ_FILES)
+	$(ARMGNU)-objcopy $(BUILD_DIR)/bootloader.elf -O binary bootloader.img
+
+clean:
+	rm -rf $(BUILD_DIR) *.img *.elf *.o
+
+qemu: bootloader.img
+	qemu-system-aarch64 $(QEMUFLAGS) -kernel bootloader.img -initrd ../initramfs.cpio

Lab2/bootloader/include/gpio.h

@@ -0,0 +1,25 @@
+#ifndef GPIO_H
+#define GPIO_H
+
+#define MMIO_BASE       0x3F000000
+
+#define GPFSEL0         ((volatile unsigned int*)(MMIO_BASE+0x00200000))
+#define GPFSEL1         ((volatile unsigned int*)(MMIO_BASE+0x00200004))
+#define GPFSEL2         ((volatile unsigned int*)(MMIO_BASE+0x00200008))
+#define GPFSEL3         ((volatile unsigned int*)(MMIO_BASE+0x0020000C))
+#define GPFSEL4         ((volatile unsigned int*)(MMIO_BASE+0x00200010))
+#define GPFSEL5         ((volatile unsigned int*)(MMIO_BASE+0x00200014))
+#define GPSET0          ((volatile unsigned int*)(MMIO_BASE+0x0020001C))
+#define GPSET1          ((volatile unsigned int*)(MMIO_BASE+0x00200020))
+#define GPCLR0          ((volatile unsigned int*)(MMIO_BASE+0x00200028))
+#define GPLEV0          ((volatile unsigned int*)(MMIO_BASE+0x00200034))
+#define GPLEV1          ((volatile unsigned int*)(MMIO_BASE+0x00200038))
+#define GPEDS0          ((volatile unsigned int*)(MMIO_BASE+0x00200040))
+#define GPEDS1          ((volatile unsigned int*)(MMIO_BASE+0x00200044))
+#define GPHEN0          ((volatile unsigned int*)(MMIO_BASE+0x00200064))
+#define GPHEN1          ((volatile unsigned int*)(MMIO_BASE+0x00200068))
+#define GPPUD           ((volatile unsigned int*)(MMIO_BASE+0x00200094))
+#define GPPUDCLK0       ((volatile unsigned int*)(MMIO_BASE+0x00200098))
+#define GPPUDCLK1       ((volatile unsigned int*)(MMIO_BASE+0x0020009C))
+
+#endif

Lab2/bootloader/include/stdint.h

@@ -0,0 +1,16 @@
+#ifndef _STDINT_H
+#define _STDINT_H
+
+typedef signed char         int8_t;
+typedef short               int16_t;
+typedef int                 int32_t;
+typedef long long           int64_t;
+
+typedef unsigned char       uint8_t;
+typedef unsigned short      uint16_t;
+typedef unsigned int        uint32_t;
+typedef unsigned long long  uint64_t;
+
+typedef unsigned int size_t;
+
+#endif /* _STDINT_H */

Lab2/bootloader/include/uart.h

@@ -0,0 +1,41 @@
+#include "../include/stdint.h"
+
+#ifndef UART_H
+#define UART_H
+
+/* Auxilary mini UART registers */
+#define AUX_ENABLE      ((volatile unsigned int*)(MMIO_BASE+0x00215004))
+#define AUX_MU_IO       ((volatile unsigned int*)(MMIO_BASE+0x00215040))
+#define AUX_MU_IER      ((volatile unsigned int*)(MMIO_BASE+0x00215044))
+#define AUX_MU_IIR      ((volatile unsigned int*)(MMIO_BASE+0x00215048))
+#define AUX_MU_LCR      ((volatile unsigned int*)(MMIO_BASE+0x0021504C))
+#define AUX_MU_MCR      ((volatile unsigned int*)(MMIO_BASE+0x00215050))
+#define AUX_MU_LSR      ((volatile unsigned int*)(MMIO_BASE+0x00215054))
+#define AUX_MU_MSR      ((volatile unsigned int*)(MMIO_BASE+0x00215058))
+#define AUX_MU_SCRATCH  ((volatile unsigned int*)(MMIO_BASE+0x0021505C))
+#define AUX_MU_CNTL     ((volatile unsigned int*)(MMIO_BASE+0x00215060))
+#define AUX_MU_STAT     ((volatile unsigned int*)(MMIO_BASE+0x00215064))
+#define AUX_MU_BAUD     ((volatile unsigned int*)(MMIO_BASE+0x00215068))
+
+
+/**
+ * Set baud rate and characteristics (115200 8N1) and map to GPIO
+ */
+void uart_init();
+
+
+/**
+ * Receive a character
+ */
+char uart_getc();
+
+/**
+ * Display a string
+ */
+void uart_puts(char *s);
+
+
+char uart_recv();
+
+void itos(uint32_t value, char *str);
+#endif

Lab2/bootloader/src/link.ld

@@ -0,0 +1,21 @@
+SECTIONS
+{
+    . = 0x60000;
+    __bootloader_start = .;
+    .text : { KEEP(*(.text.boot)) *(.text .text.* .gnu.linkonce.t*) }
+    .rodata : { *(.rodata .rodata.* .gnu.linkonce.r*) }
+    .data : { *(.data .data.* .gnu.linkonce.d*) }
+    .bss (NOLOAD) : {
+        . = ALIGN(16);
+        __bss_start = .;
+        *(.bss .bss.*)
+        *(COMMON)
+        __bss_end = .;
+    }
+    _end = .;
+    __bootloader_end = .;
+
+   /DISCARD/ : { *(.comment) *(.gnu*) *(.note*) *(.eh_frame*) }
+}
+__bss_size = (__bss_end - __bss_start)>>3;
+__bootloader_size = (__bootloader_end - __bootloader_start) >> 3;

Lab2/bootloader/src/main.c

@@ -0,0 +1,58 @@
+#include "../include/uart.h"
+#include "../include/stdint.h"
+
+void main()
+{
+    // set up serial console
+    uart_init();
+    uart_puts("bootloader is coming~\n");
+
+    uint32_t file_size = 0;
+    size_t index = 0;
+    // Buffer to store received data
+    uint8_t byte;
+
+    while(1) {
+        if(uart_recv() == ((uint8_t)77)) break;
+    }
+    uart_puts("ready for receiving kernel size.\n");
+
+
+    // Receive the file size as a 4-byte integer in little-endian format
+    for (int i = 0; i < 4; i++) {
+        byte = uart_recv();
+        file_size |= ((uint32_t)byte) << (8 * i);
+    }
+
+    char file_size_str[32];  // Adjust the buffer size as needed
+    itos(file_size, file_size_str);
+
+    uart_puts("kernel size :");
+    uart_puts(file_size_str);
+    uart_puts(" bytes.\n");
+
+    while(1) {
+        uart_puts("ready for receiving kernel.\n");
+        if(uart_recv() == ((uint8_t)77)) break;
+    }
+
+
+    char *kernel = (char *)0x80000;
+    while (index < file_size) {
+        // Receive a byte
+        byte = uart_recv();
+        // Write the byte to memory
+        *(kernel + index) = byte;
+        // Increment the index
+        index++;
+    }
+
+    uart_puts("finished loading kernel~\n");
+
+
+    // restore arguments and jump to the new kernel.
+    asm volatile (
+        "mov x30, 0x80000;" // Move the immediate value 0x80000 to the link register (x30)
+        "ret;"              // Return from subroutine (this will jump to the address in x30)
+    );
+}

Lab2/bootloader/src/start.S

@@ -0,0 +1,40 @@
+.section ".text.boot"
+
+.global _start
+
+_start:
+    /* relocate bootloader */
+    ldr x1, =0x80000             //address for relocation.
+    ldr x2, =__bootloader_start
+    ldr w3, =__bootloader_size
+
+relocate:
+    ldr x4, [x1], #8
+    str x4, [x2], #8
+    sub w3, w3, #1
+    cbnz w3, relocate
+
+    /* set stack pointer */
+    ldr x1, =_start
+    mov sp, x1
+
+
+bss_init:  
+    // clear bss
+    ldr     x1, =__bss_start
+    ldr     w2, =__bss_size
+
+clear_bss_memory:  
+    cbz     w2, jump_to_main
+    str     xzr, [x1], #8
+    sub     w2, w2, #1
+    cbnz    w2, clear_bss_memory
+
+// jump to C code, should not return
+jump_to_main:  
+    bl      main-0x20000
+    // for failsafe, halt this core too
+    b       halt
+
+halt:  
+    b       halt