Root/Documentation/printk-formats.txt

Source at commit ec7cab4cbb721bff91ec924ec691efd8daf36579 created 12 years 8 months ago.
By Maarten ter Huurne, MIPS: JZ4740: A320: Updated quickstart documentation.
1If variable is of Type, use printk format specifier:
2---------------------------------------------------------
3        int %d or %x
4        unsigned int %u or %x
5        long %ld or %lx
6        unsigned long %lu or %lx
7        long long %lld or %llx
8        unsigned long long %llu or %llx
9        size_t %zu or %zx
10        ssize_t %zd or %zx
11
12Raw pointer value SHOULD be printed with %p.
13
14u64 SHOULD be printed with %llu/%llx, (unsigned long long):
15
16    printk("%llu", (unsigned long long)u64_var);
17
18s64 SHOULD be printed with %lld/%llx, (long long):
19
20    printk("%lld", (long long)s64_var);
21
22If <type> is dependent on a config option for its size (e.g., sector_t,
23blkcnt_t, phys_addr_t, resource_size_t) or is architecture-dependent
24for its size (e.g., tcflag_t), use a format specifier of its largest
25possible type and explicitly cast to it. Example:
26
27    printk("test: sector number/total blocks: %llu/%llu\n",
28        (unsigned long long)sector, (unsigned long long)blockcount);
29
30Reminder: sizeof() result is of type size_t.
31
32Thank you for your cooperation and attention.
33
34
35By Randy Dunlap <rdunlap@xenotime.net>
36

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