BlockDev_API_Int13_Chain_Check

include vmm.inc

include blockdev.inc

mov ax, 1607h ; device callout

mov bx, BlockDev_Device_ID ; block device ID

mov cx, BlockDev_API_Int13_Chain_Check

int 2Fh

jcxz okay ; zero if okay to load block device

The BlockDev_API_Int13_Chain_Check function notifies TSRs and MS-DOS device drivers that have hooked the ROM BIOS Interrupt 13h address that a block device is about to load. This notification gives the TSR or device driver a chance to cancel the loading.

Return Value

The TSR or device driver sets the CX register to zero if it is permissible for block devices, such as WDCTRL, to load even though the MS-DOS Interrupt 13h chain has been modified.