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I applied the ST FWU reference solution on our own platform based on the STM32MP157F. I have a few questions to clarify the default behavior: What is the default behavior in the early boot stage? Do ...
user3518295's user avatar
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-2 votes
0 answers
110 views

I have added some stuff in the new-stuff branch, and when I try to boot, it gets to the last "Entering protected mode..." step, but if I revert my kernel to how it was, it works just fine ...
Connor Thomson's user avatar
  • 31
2 votes
2 answers
119 views

As you can see down at bottom on my stage 2 boot loader, I have a VGA write thing (Prints out "Starting kernel...", but when I use it, the system starts to boot loop, I have no idea why this ...
Connor Thomson's user avatar
  • 31
5 votes
1 answer
79 views

I am having a problem with a bootloader I made. Mostly used code snippets from wiki.osdev.org, and screeck (on Github and Youtube) . The issue is: the bootloader cannot jump farther than 0xFFFFF, and ...
Alexbrine's user avatar
  • 53
3 votes
2 answers
136 views

I am working on a small os with a custom boot loader targeting BIOS. For this, I need to map the kernel to its canonical high address space (0xFFFFFFFF80000000) and jump to its entry point. For this, ...
Holz's user avatar
  • 133
4 votes
1 answer
111 views

im trying to make a simple bootloader that loads a simple kernel and the problem is that the kernel code doesnt run i do see prints from the bootloader but not from the kernel here is my code: boot....
someuser's user avatar
  • 43
-3 votes
1 answer
105 views

im following a udemy course on making an operating system from scratch, but i have run into a very bizarre error: Makefile: DISK = os.img KERNEL = kernel.bin BOOTSECTOR = bootsector NASM = nasm QEMU =...
AutisticCoder's user avatar
  • 9
2 votes
0 answers
82 views

I try to code the transition from protected mode to IA-32e mode. It's a task in college. The problem that I can't debug 32 bit bootloader. I can only run QEMU and tell based on its output whether this ...
chav1s's user avatar
  • 47
1 vote
0 answers
32 views

I’m working on STM32H755 bootloader project where I need to verify the integrity of the application firmware using a CRC32 checksum. The build system uses srec_cat to append the CRC32 at the end of ...
Shiddesh's user avatar
  • 21
1 vote
0 answers
47 views

I'm working on a project using the ATSAMD51J19A with a UF2 bootloader, which appears as a storage device over USB for easy firmware updates. Currently, the bootloader sets an LED using a PWM signal on ...
user31568508's user avatar
  • 11
1 vote
1 answer
245 views

I'm writing a custom bootloader from scratch for an STM32 project. Currently, the bootloader only initializes and jumps to the main application. I'm gradually adding peripherals one by one. Everything ...
Afshin Rad's user avatar
  • 11
3 votes
1 answer
153 views

I am trying to write a simple bootloader which loads my program from LBA=1 into memory and jumps to its start. I emulate my bootloader in qemu with -drive flag passed. When I try to read blocks from ...
Alex Gendelbergen's user avatar
  • 33
4 votes
1 answer
191 views

So I thought I'd try to make a DOS copy but it runs on a floppy and its just a simple plug and play with fat12 partition for user applications and drivers. I first attempted to load my kernel using ...
laween's user avatar
  • 91
4 votes
2 answers
191 views

I threw together a makeshift MBR for a chainloader project I have been working on for sometime now. I tested on QEMU and BOCHS and no issues, besides throwing earlier 386 BIOS images into the mix (...
EchoXTeknology's user avatar
  • 109
1 vote
1 answer
115 views

I'm writing a bootloader in x86 Assembly for my operating system. Note that I have already wrote a few bootloaders and I never faced this problem. This is the code that I compile with NASM (precisely ...
varevind's user avatar
  • 51
2 votes
1 answer
104 views

I'm working on a retro programming project and running into trouble with my bootloader setup. I'm using: Turbo Assembler 4.01 for the first-stage bootloader (x86 Assembly) Turbo C 2.0 for the second-...
Amir Khan's user avatar
  • 31
2 votes
1 answer
91 views

I'm writing a UEFI application in Zig. I'm calling GetMemoryMap() twice: once to get the required buffer size, then again after allocating the buffer using AllocatePool(). Here's my code: fn ...
OrderChaos's user avatar
  • 33
0 votes
0 answers
96 views

I am working on a simple bootloader in assembly. everything works fine until i enable paging and jump to 64 bit mode but then qemu just flickers. i think its a page fault but i am not sure what's ...
ebenezer gmeskel's user avatar
  • 1
0 votes
1 answer
56 views

I can't pass the address of the linear framebuffer to vbe I tried via: mov eax, [ModeInfoBlock + 0x28] mov [0x8000], eax but 0x8000 is always zero, but if I write mov [0x8000], 0x12345, then it ...
Cursor's user avatar
  • 1
-5 votes
2 answers
94 views

For some reason every time I try entering 32bit protected mode.. it always FLICKERS AND FLICKERS FOR NO REASON.. I am using QEMU and my kernel is being assembled into a raw binary and then written ...
user avatar
1 vote
1 answer
79 views

Avr-gcc 7.1, Win10. When compiling a simple LED blinker C code using avr-gcc, it outputs: Invoking the avr-gcc is done by hand using: avr-gcc -g -Os -mmcu=attiny13a -c "Attiny_blink_01.c" ...
Noideas's user avatar
  • 127
0 votes
1 answer
53 views

I have a function to write data in framebuffer: _print_c: mov ax, di mov edi, 0x000B8000 mov byte [edi], al mov ax, si mov byte [edi + 1], al shl byte [edi + 1], 4 and ...
Daniil's user avatar
  • 17
1 vote
1 answer
54 views

Problem I have a working PM code, but as soon as I add LM setup, the GDT base gets assigned a garbage address, cr registers don't load properly and I get into a boot loop. I tried hard-coding the ...
Adi Mehmedičević's user avatar
  • 43
1 vote
2 answers
167 views

I’ve successfully enabled Secure Boot V2 on my ESP32 device using ESP-IDF, and everything is working fine. Now, I want to enable Flash Encryption as the next step in securing my firmware. I’m ...
mauli02k's user avatar
  • 81
0 votes
0 answers
80 views

I am trying to set up gdb and Qemu to debug the boot loader code in the linux kernel. I have compiled a vmlinux image with all the correct flags. I run a qemu instance with qemu-system-x86_64 -m 256 -...
Jeremy's user avatar
  • 185
3 votes
1 answer
88 views

Problem I have assembly code that switches to 32bit mode and prints a character successfully when I have it inside the boot sector - But when I use a disk read to load the code to the next sector the ...
Adi Mehmedičević's user avatar
  • 43
2 votes
1 answer
57 views

It's my first time writing x86-16 assembly. I'm writing a bootloader game, but I'm struggling with iterating through level data. I'm attempting to iterate through a 2d array - each byte of this array ...
Nishiiya's user avatar
  • 23
2 votes
1 answer
108 views

Recently I tried to implement the bootloader from scratch on x86 assembly using NASM. I am aware that the BIOS loads the bootsector to address 0x7C00 and for that reason all the offsets and memory ...
Zero's user avatar
  • 23
0 votes
1 answer
49 views

I am learning to write a 16-bit bootloader using NASM with BIOS interrupts to print strings to the screen. I’ve created a simple print subroutine in an external file (printer.asm), and I'm using %...
Kushal's user avatar
  • 33
2 votes
0 answers
76 views

I've recently been working on a mini operating system written completely from scratch. After implementing a bootloader and minimalised kernel, I tested the whole program on GDB, with the breakpoint ...
Yoinksawse's user avatar
  • 79
1 vote
3 answers
125 views

I'm developing a small bootloader project in Assembly for BIOS Legacy (real mode). It displays a disk selection menu using BIOS interrupts (INT 10h for video, INT 16h for keyboard). However, I'm ...
RemoveOS's user avatar
  • 13
0 votes
0 answers
50 views

The question is about how the rauc status mark-active other command work with the layouts with only 1 slot for the element (A/B scheme is not supported). We use RAUC for updates management on our ...
user3518295's user avatar
  • 320
0 votes
1 answer
84 views

I am trying to develop a bootloader with STM32F469BIT mcu. First of all, I divided the 2048K flash area allocated to me into zones according to certain sector addresses. These areas; Bootloader -> ...
mmercan's user avatar
  • 1
1 vote
0 answers
57 views

Just making a simple OS as a beginner for my assembly project. I have this very simple bootloader which prints a character B and reads the second sector (kernel) from drive and loads it at 10000h ...
Solid's user avatar
  • 13
1 vote
0 answers
73 views

https://github.com/UdayKhare09/EXO_OS is my repo. I am working on a custom bootloader for my operating system, and I am encountering an issue where the bootloader fails to load more than 53 sectors ...
Uday Khare's user avatar
  • 11
0 votes
0 answers
36 views

[ORG 0x7C00] [BITS 16] %define CODE_OFFSET 0x8 %define DATA_OFFSET 0x10 %define KERNEL_POS 0x1000 ; 4096 bits dec, 512 bytes ; loader - 512 size bytes, ; then kernel will ...
Daniil's user avatar
  • 17
0 votes
0 answers
48 views

I'm currently working on a custom board based on the nRF52840, using SoftDevice S140 v7.0.1 and nRF5 SDK v16.0.1. I’ve integrated the BLE Buttonless DFU example (examples/dfu/secure_bootloader/...
kasijadi_lightnium's user avatar
  • 1
2 votes
1 answer
90 views

I am writing a simple bootloader (and, hopefully soon, an operating system). I have been making progress, but this part is stumping me a bit. I am writing this operating system and bootloader into a ...
Ryan Grube's user avatar
  • 23
-1 votes
1 answer
117 views

org 0x7c00 BOOTDRIVE equ 0x9000 flatcode equ 0x0008 flatdata equ 0x0010 ...
sanzenyou's user avatar
  • 107
2 votes
1 answer
149 views

I am making software bootloader for my STM32F407, and i managed to successfully write firmware in flash, starting at address 0x08004000 and I want to jump to it so my board can start executing that ...
dinajs's user avatar
  • 118
4 votes
1 answer
150 views

I am trying to make software bootloader for my STM32F407 project and I ran into some issue. The whole idea is that I send data using UART protocol from my PC to STM32F407. Data that I am sending is ...
dinajs's user avatar
  • 118
0 votes
0 answers
76 views

[ORG 0x7C00] [BITS 16] CODE_OFFSET equ 0x8 DATA_OFFSET equ 0x10 KERNEL_POS equ 0x1000 ; 4096 bits dec, 512 bytes ; loader - 512 size bytes, ; then kernel will placed to ...
Daniil's user avatar
  • 17
4 votes
1 answer
136 views

I am trying to make my own OS and am currently stuck on one tiny problem. My welcome messages are not loading in the terminal. Other than that, everything seems to work fine. (I'm not too sure, so ...
James Tan's user avatar
  • 59
0 votes
1 answer
86 views

I need the total disk size in bytes to be displayed at startup, as well as some additional information. I tried doing it this way, but the data displayed on the screen was completely wrong: [BITS 16] [...
PRoX's user avatar
  • 23
2 votes
1 answer
135 views

I've been trying to build a custom OS following the steps in this guide. However, I continue to get the following error from my Makefile, init :: non DOS media Cannot initialize '::' ::kernel.bin: ...
Joshua Alexander's user avatar
  • 31
0 votes
0 answers
256 views

How do I force u-boot to read spi nor flash in 4 byte addressing mode rather than switching from 3 bytes to 4? Hardware: I have a custom-built board based on mt7628nn with 128 MB DDR2 RAM and 32 mb ...
Baldeagle's user avatar
  • 25
2 votes
1 answer
97 views

I'm writing a small EFI application with gnu-efi, which boots depending on the Wake-Up Type into Ubuntu or Windows. The application works, but I want to configure the WakeUp Type - Boot Option mapping ...
KastenKlicker's user avatar
  • 47
0 votes
0 answers
67 views

Hi I am trying to develop USART IAP Bootloader code for STM32F051_Disco but when Bootloader call JUMP User App it's getting hard fault error. I have checked (Memory-File Compare) code copied into ...
Bhavesh Moradiya's user avatar
  • 1,373
3 votes
1 answer
93 views

I'm writing a custom OS with my own bootloader and trying to switch from an assembly-based kernel (kernel.asm) to a C-based kernel (kernel.c). When using kernel.asm, everything works fine. But when I ...
Sunil KhoRwal's user avatar
  • 118
1 vote
0 answers
119 views

I'm currently developing an operating system that uses the limine bootloader and follows the limine boot protocol. However, I've encountered an issue: when I call init_PIC(), the CPU resets ...
Viliam Holly's user avatar
  • 292

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