If R0 bit 3 is set:
=> R0 = flags
R1 = input size, or -1 means don't return max output size
<= R0 = required workspace size
R1 = maximum output size (-1 means don't know/not asked)
If R0 bit 3 is clear:
=> R0 = flags
R1 = workspace pointer
R2 = input pointer
R3 = bytes of input available
R4 = output pointer
R5 = bytes of output space available
<= R0 = status
R1 preserved
R2 = pointer to first unused input byte
R3 = input bytes unused
R4 = pointer to first unused output byte
R5 = unused output space remaining
Call this SWI initially with R0 = 8 and R1 = input file size, using the sizes it reports to allocate workspace and output buffers as appropriate. Note that the current algorithm always returns R1 = -1, so you must get this size by some other means. Then call repeatedly with R0 bit 3 clear until all the data is processed (as reported via the status bits returned in R0). If the input is exhausted (R3 < 12, R0 bit 1 set) the unused input must be resupplied.
If all the input data can be presented at once (R0 bits 0,1 clear) and the output buffer is large enough, a faster algorithm is used.
See PRM 4, page 104.
Squash_Decompress flags
Bit Meaning if set
0 Continuing existing operation
1 More input remains after this
2 Assume all ouput will fit in buffer (if bits 0,1 clear a faster algorithm is used)
3 return workspace needed and max output size (all other bits must be 0)
4-31 0 (reserved)
Squash_Decompress statuses
Value Meaning
0 Operation complete
1 Input exhausted (R3 < 12)
2 Output space exhausted (R5 = 0)
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