From 176b6eb808f4d02d871c30f6ec19daa179f374d1 Mon Sep 17 00:00:00 2001
From: Marvin Borner
Date: Fri, 9 Jul 2021 14:43:12 +0200
Subject: Multiboot structs
---
run | 2 +-
src/entry/bootsector.asm | 2 ++
src/loader/impl/mb1.c | 25 ++++++++++++++++++-------
src/loader/inc/cfg.h | 2 ++
src/loader/int.c | 9 +++------
src/loader/main.c | 8 ++++++--
6 files changed, 32 insertions(+), 16 deletions(-)
diff --git a/run b/run
index 72ae723..ee456ae 100755
--- a/run
+++ b/run
@@ -105,7 +105,7 @@ build() {
}
emulate() {
- qemu-system-i386 -d guest_errors -cpu max -serial stdio -m 256M -vga std -drive file=build/disk.img,format=raw,index=1,media=disk
+ qemu-system-i386 -enable-kvm -d guest_errors -cpu max -serial stdio -m 256M -vga std -drive file=build/disk.img,format=raw,index=1,media=disk
}
# Always generate updated configurations
diff --git a/src/entry/bootsector.asm b/src/entry/bootsector.asm
index a98c22b..d66fb09 100644
--- a/src/entry/bootsector.asm
+++ b/src/entry/bootsector.asm
@@ -105,7 +105,9 @@ protected_mode:
mov gs, ax
mov ss, ax
+ push dx ; Pass disk
call loader
+
jmp error_loop
bits 16
diff --git a/src/loader/impl/mb1.c b/src/loader/impl/mb1.c
index 5541c6e..4aa267a 100644
--- a/src/loader/impl/mb1.c
+++ b/src/loader/impl/mb1.c
@@ -9,7 +9,7 @@
// The address where data gets stored
#define MB1_LOAD_ADDRESS 0x10000
-struct multiboot_entry {
+struct mb1_entry {
u32 magic;
u32 flags;
u32 checksum; // Everything after that is optional
@@ -25,7 +25,7 @@ struct multiboot_entry {
};
// The (really simple) multiboot checksum algorithm
-static u32 mb1_checksum(struct multiboot_entry *entry)
+static u32 mb1_checksum(struct mb1_entry *entry)
{
return -(entry->magic + entry->flags);
}
@@ -34,16 +34,27 @@ static u32 mb1_checksum(struct multiboot_entry *entry)
static u32 mb1_store(void *data, u32 size)
{
static u32 offset = 0;
- memcpy((void *)MB1_LOAD_ADDRESS, data, size);
+ memcpy((void *)(MB1_LOAD_ADDRESS + offset), data, size);
offset += size;
- return MB1_LOAD_ADDRESS + (size - offset);
+ return MB1_LOAD_ADDRESS + (offset - size);
}
// Load the mb1 structs into memory
-static void mb1_load(struct multiboot_entry *entry)
+static void mb1_load(struct mb1_entry *entry)
{
- (void)mb1_store;
(void)entry;
+
+ struct mb1_info info_struct = { 0 };
+ struct mb1_info *info = (void *)mb1_store(&info_struct, sizeof(info_struct));
+
+ // Set boot device
+ info->flags |= MB1_INFO_BOOTDEV;
+ info->boot_device = boot_disk;
+
+ // Set bootloader name
+ info->flags |= MB1_INFO_BOOT_LOADER_NAME;
+ char loader_name[] = "SegelBoot";
+ info->boot_loader_name = mb1_store(loader_name, sizeof(loader_name));
}
// Jump to kernel with correct info pointer in eax
@@ -71,7 +82,7 @@ u8 mb1_detect(struct cfg_entry *cfg)
return 0;
// Find start of multiboot entry by searching for magic
- struct multiboot_entry *entry = 0;
+ struct mb1_entry *entry = 0;
for (u32 i = 0; i < sizeof(header); i++) {
u32 *p = (u32 *)&header[i];
if (*p == MB1_MAGIC) {
diff --git a/src/loader/inc/cfg.h b/src/loader/inc/cfg.h
index f3a15ab..cb91ab2 100644
--- a/src/loader/inc/cfg.h
+++ b/src/loader/inc/cfg.h
@@ -6,6 +6,8 @@
#include <def.h>
#include <impl.h>
+extern u8 boot_disk;
+
// Global config element index (can actually be anything but wth)
#define CFG_GLOBAL 0
diff --git a/src/loader/int.c b/src/loader/int.c
index 67b80f0..6bfea09 100644
--- a/src/loader/int.c
+++ b/src/loader/int.c
@@ -125,19 +125,16 @@ static u32 int_event_handler(struct int_frame *frame)
* Universal handler
*/
-static u8 int_enabled = 1;
-
u32 int_handler(u32 esp);
u32 int_handler(u32 esp)
{
struct int_frame *frame = (struct int_frame *)esp;
- if (frame->int_no < 32) {
+ if (frame->int_no < 32)
int_trap_handler(frame);
- } else if (int_enabled && frame->int_no < 48) {
+ else if (frame->int_no < 48)
esp = int_event_handler(frame);
- } else if (frame->int_no >= 48) {
+ else
panic("Unknown interrupt\n");
- }
pic_ack(frame->int_no);
return esp;
diff --git a/src/loader/main.c b/src/loader/main.c
index aa8e62d..ed3014b 100644
--- a/src/loader/main.c
+++ b/src/loader/main.c
@@ -15,9 +15,13 @@
* Entry
*/
-int start(void);
-int start(void)
+u8 boot_disk = 0;
+
+int start(u8 disk);
+int start(u8 disk)
{
+ boot_disk = disk;
+
vga_clear();
serial_install();
--
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