From f8d841fe268ebba43686729af535e035702438f7 Mon Sep 17 00:00:00 2001
From: Marvin Borner
Date: Fri, 9 Apr 2021 01:09:07 +0200
Subject: Using booting drive instead of ata detection
---
boot/entry.asm | 3 +++
boot/load.c | 69 +---------------------------------------------------------
2 files changed, 4 insertions(+), 68 deletions(-)
(limited to 'boot')
diff --git a/boot/entry.asm b/boot/entry.asm
index 8f12dff..dc65b97 100644
--- a/boot/entry.asm
+++ b/boot/entry.asm
@@ -454,6 +454,9 @@ protected_mode:
mov ax, (gdt_tss - gdt) | 0b11 ; Load TSS in ring 3
ltr ax
+ mov eax, drive ; Pass drive to kernel loader
+ push eax ; Push as third kernel parameter
+
mov eax, vid_info ; Pass VBE struct to kernel loader
push eax ; Push as second kernel parameter
diff --git a/boot/load.c b/boot/load.c
index 12102a2..dfa6e9c 100644
--- a/boot/load.c
+++ b/boot/load.c
@@ -508,55 +508,6 @@ static void print(const char *data)
* IDE/ATA
*/
-static u8 *ide_buf = NULL;
-
-static void ide_select_drive(u8 bus, u8 drive)
-{
- if (bus == ATA_PRIMARY) {
- if (drive == ATA_MASTER)
- outb(ATA_PRIMARY_IO + ATA_REG_HDDEVSEL, 0xa0);
- else
- outb(ATA_PRIMARY_IO + ATA_REG_HDDEVSEL, 0xb0);
- } else {
- if (drive == ATA_MASTER)
- outb(ATA_SECONDARY_IO + ATA_REG_HDDEVSEL, 0xa0);
- else
- outb(ATA_SECONDARY_IO + ATA_REG_HDDEVSEL, 0xb0);
- }
-}
-
-static u8 ide_find(u8 bus, u8 drive)
-{
- u16 io = bus == ATA_PRIMARY ? ATA_PRIMARY_IO : ATA_SECONDARY_IO;
- ide_select_drive(bus, drive);
-
- // Reset
- outb(io + ATA_REG_SECCOUNT0, 0);
- outb(io + ATA_REG_LBA0, 0);
- outb(io + ATA_REG_LBA1, 0);
- outb(io + ATA_REG_LBA2, 0);
-
- // Identify
- outb(io + ATA_REG_COMMAND, ATA_CMD_IDENTIFY);
- u8 status = inb(io + ATA_REG_STATUS);
- if (!status)
- return 0;
-
- while ((inb(io + ATA_REG_STATUS) & ATA_SR_BSY) != 0)
- ;
-
- do {
- status = inb(io + ATA_REG_STATUS);
- if (status & ATA_SR_ERR)
- return 0;
- } while ((status & ATA_SR_DRQ) == 0);
-
- for (int i = 0; i < BLOCK_COUNT; i++)
- *(u16 *)(ide_buf + i * 2) = inw(io + ATA_REG_DATA);
-
- return 1;
-}
-
static void ide_delay(u16 io) // 400ns
{
for (int i = 0; i < 4; i++)
@@ -611,23 +562,6 @@ static u32 ata_read(void *buf, u32 lba, u32 sector_count, u8 drive)
return sector_count;
}
-static u8 ata_probe(void)
-{
- for (u8 i = 0; i < 4; i++) {
- u32 bus = i < 2 ? ATA_PRIMARY : ATA_SECONDARY;
- u32 drive = i % 2 ? ATA_MASTER : ATA_SLAVE;
-
- if (!ide_find(bus, drive))
- continue;
-
- u8 found_drive = (bus << 1) | drive;
- // TODO: What about the other drives?
- return found_drive;
- }
-
- return 0;
-}
-
/**
* EXT2
*/
@@ -885,12 +819,11 @@ static s32 elf_load(const char *path, u8 drive)
* Let's go!
*/
-int main(void *first, void *second)
+int main(void *first, void *second, u8 drive)
{
serial_install();
print("Loaded bootloader!\n");
- u8 drive = ata_probe();
assert(drive);
s32 elf = elf_load("/apps/kernel/exec", drive);
--
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