diff options
Diffstat (limited to 'init/init.c')
| -rw-r--r-- | init/init.c | 31 |
1 files changed, 14 insertions, 17 deletions
diff --git a/init/init.c b/init/init.c index 17e605b..c444089 100644 --- a/init/init.c +++ b/init/init.c @@ -288,30 +288,27 @@ void set_term(int fd) tcsetattr(fd, TCSANOW, &tty); } -/* How much memory does this machine have? */ +/* How much memory does this machine have? + Units are kBytes to avoid overflow on 4GB machines */ static int check_free_memory() { struct sysinfo info; + unsigned int result, u, s=10; - /* Pre initialize mem_unit in case this kernel is something prior to - * the linux 2.4 kernel (which will actually fill in mem_unit... */ - sysinfo(&info); if (sysinfo(&info) != 0) { - printf("Error checking free memory: %s\n", strerror(errno)); + perrorMsg("Error checking free memory: "); return -1; } - /* Kernels prior to 2.4.x will return info.mem_unit==0, so cope... */ - if (info.mem_unit==0) { - info.mem_unit=1; - } - info.mem_unit*=1024; - - /* Note: These values can in theory overflow a 32 bit unsigned long (i.e. - * mem >= Gib), but who puts more then 4GiB ram+swap on an embedded - * system? */ - info.totalram/=info.mem_unit; - info.totalswap/=info.mem_unit; - return(info.totalram+info.totalswap); + + /* Kernels 2.0.x and 2.2.x return info.mem_unit==0 with values in bytes. + * Kernels 2.4.0 return info.mem_unit in bytes. */ + u = info.mem_unit; + if (u==0) u=1; + while ( (u&1) == 0 && s > 0 ) { u>>=1; s--; } + result = (info.totalram>>s) + (info.totalswap>>s); + result = result*u; + if (result < 0) result = INT_MAX; + return result; } static void console_init() |