The host_scribble Pointer

The high-level code supplies a pair of memory allocation functions, 150 and 151, which are guaranteed to return memory in the first 16~MB of physical memory. This memory is, therefore, suitable for use with DMA. The amount of memory allocated per request <#1428#> must<#1428#> be a multiple of 512 bytes, and <#1429#> must<#1429#> be less than or equal to 4096 bytes. The total amount of memory available via 152 is a complex function of the 153 structure variables 154, 155, and 156. The 157 pointer is available to point to a region of memory allocated with 158. The low-level SCSI driver is responsible for managing this pointer and its associated memory, and should free the area when it is no longer needed.