more ata stuff

2026-06-20 21:02:59 -05:00
parent b384723dbd
commit 0f84acde30
5 changed files with 248 additions and 45 deletions
--- a/kernel/drivers/atapi/ata_stubs.S
+++ b/kernel/drivers/atapi/ata_stubs.S
@@ -2,6 +2,149 @@

 .code32

-.global ident_drives
-ident_drives:
+.extern selected_drive_primary
+.extern selected_drive_secondary
+
+.global ident_device
+ident_device:
+    push %ebp 
+    mov %esp, %ebp 
+
+    push %ebx 
+    push %ecx 
+    push %edx
+    push $0
+
+    mov 8(%ebp), %ebx    # ebx = bus base address
+    mov 12(%ebp), %ecx   # ecx = drive select mask
+
+    # drive select
+    mov %ebx, %edx
+    add $IO_DRIVE_SELECT_REG, %edx
+    mov %cl, %al
+    outb %al, (%dx)
+
+    xor %eax, %eax
+    # clear sector count and LBA
+    mov %ebx, %edx
+    add $IO_SECTOR_COUNT_REG, %edx
+    outb %al, (%dx)
+
+    mov %ebx, %edx
+    add $IO_LBA_LO_REG, %edx
+    outb %al, (%dx)
+
+    mov %ebx, %edx
+    add $IO_LBA_MID_REG, %edx
+    outb %al, (%dx)
+
+    mov %ebx, %edx
+    add $IO_LBA_HI_REG, %edx
+    outb %al, (%dx)
+
+    # send ident
+    mov %ebx, %edx
+    add $IO_CMD_REG, %edx
+    mov $0xEC, %al
+    outb %al, (%dx)
+
+    mov %ebx, %edx
+    add $IO_STATUS_REG, %edx
+    inb (%dx), %al
+    inb (%dx), %al
+    inb (%dx), %al
+    inb (%dx), %al
+
+    cmp $0xFF, %al          
+    je not_found
+    test %al, %al      
+    jz not_found
+
+poll_status:
+    inb (%dx), %al
+    test $STATUS_REG_BSY, %al
+    jnz poll_status
+
+check_ata:
+    mov %ebx, %edx
+    add $IO_LBA_MID_REG, %edx
+    inb (%dx), %al
+    test %al, %al
+    jnz check_atapi
+    
+    mov %ebx, %edx
+    add $IO_LBA_HI_REG, %edx
+    inb (%dx), %al
+    test %al, %al
+    jnz check_atapi
+
+    mov $0x01, (%esp)
+    jmp poll_drq
+
+check_atapi:
+    # check if atapi device 
+    mov %ebx, %edx
+    add $IO_LBA_MID_REG, %edx
+    inb (%dx), %al 
+    cmp $0x14, %al
+    jne not_found
+
+    mov %ebx, %edx
+    add $IO_LBA_HI_REG, %edx
+    inb (%dx), %al
+    cmp $0xEB, %al
+    jne not_found
+is_atapi:
+    mov $0x02, (%esp)
+    mov %ebx, %edx
+    add $IO_CMD_REG, %edx
+    mov $(ATAPI_CMD_IDENTIFY_PACKET), %al
+    outb %al, (%dx)
+
+    mov %ebx, %edx
+    add $IO_STATUS_REG, %edx
+    inb (%dx), %al
+    inb (%dx), %al
+    inb (%dx), %al
+    inb (%dx), %al
+1:
+    inb (%dx), %al
+    test $STATUS_REG_BSY, %al
+    jnz 1b
+
+
+poll_drq:
+    mov %ebx, %edx
+    add $IO_STATUS_REG, %edx
+    inb (%dx), %al
+
+    test $STATUS_REG_ERR, %al
+    jnz error
+
+    test $STATUS_REG_DRQ, %al
+    jz poll_drq
+
+drq_set:
+    mov %ebx, %edx
+    add $IO_DATA_REG, %edx 
+
+    mov 16(%ebp), %edi
+    mov $256, %ecx 
+read_data:
+    inw (%dx), %ax
+    mov %ax, (%edi)
+    add $2, %edi
+    loop read_data
+
+    jmp done
+
+not_found:
+error: 
+    mov $0x0, (%esp)
+done:
+    pop %eax
+    pop %edx                    
+    pop %ecx
+    pop %ebx
+    leave
    ret