ref: f881d4f67254359ef348376e092c779993f57ed6
dir: /sys/src/cmd/seg.c/
#include <u.h> #include <libc.h> const char datac[] = {0,'b','w',0,'l'}; void main(int argc, char** argv) { ulong size, segsize, op, port; char* segment; ulong data; uchar *seg; data = 0; size = 1; op = -1; ARGBEGIN { case 'W': size = 2; break; case 'L': size = 4; break; case 'r': op = OREAD; break; case 'w': op = OWRITE; break; default: sysfatal("bad flag %c", ARGC()); } ARGEND; if(op == -1) sysfatal("no operation selected"); if(argc < 3) sysfatal("no address, no segsize or no segment selected"); if(op == OWRITE && argc < 4) sysfatal("no data selected"); segment = argv[0]; segsize = strtoul(argv[1], 0, 0); port = strtoul(argv[2], 0, 0); if(op == OWRITE) data = strtoul(argv[3], 0, 0); seg = segattach(0, segment, 0, segsize); if(seg == (uchar*)-1) sysfatal("segattach: %r"); if(op == OWRITE) { switch(size) { case 1: *(uchar*)(seg+port) = data; break; case 2: *(ushort*)(seg+port) = data; break; case 4: *(ulong*)(seg+port) = data; break; } } else { data = seg[port]; if(size >= 2) data |= seg[port+1] << 8; if(size >= 4) data |= (seg[port+2] << 16) | (seg[port+3] << 24); print("0x%ulx\n", data); } exits(nil); }