liminix-fork/pkgs/preinit/parseopts.c

132 lines
3.9 KiB
C

#include <unistd.h>
#include <stdint.h>
#include <string.h>
#include <unistd.h>
static int begins_with(char * str, char * prefix)
{
while(*prefix) {
if(*str == '\0') return 0;
if(*str != *prefix) return 0;
str++;
prefix++;
}
return 1;
}
char * pr_u32(int32_t input) {
static char buf[9];
const char *digits = "0123456789abcdef";
int i=0;
buf[i] = digits[(input & 0xf0000000) >> 28];
buf[i+1] = digits[(input & 0x0f000000) >> 24];
if(buf[i] != '0' || buf[i+1] != '0') i+=2;
buf[i] = digits[(input & 0x00f00000) >> 20];
buf[i+1] = digits[(input & 0x000f0000) >> 16];
if(buf[i] != '0' || buf[i+1] != '0') i+=2;
buf[i] = digits[(input & 0x0000f000) >> 12];
buf[i+1] = digits[(input & 0x00000f00) >> 8];
if(buf[i] != '0' || buf[i+1] != '0') i+=2;
buf[i] = digits[(input & 0x000000f0) >> 4];
buf[i+1] = digits[(input & 0x0000000f)];
i+=2;
buf[i] ='\0';
write(2, buf, i);
return buf;
}
void parseopts(char * cmdline, char **root, char **rootfstype) {
*root = 0;
*rootfstype = 0;
for(char *p = cmdline; *p; p++) {
if(begins_with(p, "root=")) {
*root = p + strlen("root=");
while(*p && (*p != ' ')) p++;
if(*p) {
*p = '\0';
p++;
};
};
if(begins_with(p, "rootfstype=")) {
*rootfstype = p + strlen("rootfstype=");
while(*p && (*p != ' ')) p++;
if(*p) {
*p = '\0';
p++;
};
};
};
}
#ifdef TESTS
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
// cc -DTESTS -o parseopts parseopts.c && ./parseopts
#define die(fmt, ...) do { printf(fmt, __VA_ARGS__); exit(1); } while(0)
#define S(x) #x
#define expect_equal(actual, expected) \
if(!actual || strcmp(actual, expected)) die("%d: expected \"%s\", got \"%s\"", __LINE__, expected, actual);
int main()
{
char * root = "/dev/hda1";
char * rootfstype = "xiafs";
char *buf;
// finds root= and rootfstype= options
buf = strdup("liminix console=ttyS0,115200 panic=10 oops=panic init=/bin/init loglevel=8 root=/dev/ubi0_4 rootfstype=ubifs fw_devlink=off mtdparts=phram0:18M(rootfs) phram.phram=phram0,0x40400000,18874368,65536 root=/dev/mtdblock0 foo");
parseopts(buf, &root, &rootfstype);
expect_equal(root, "/dev/mtdblock0");
expect_equal(rootfstype, "ubifs");
// in case of duplicates, chooses the latter
// also: works if the option is end of string
buf = strdup("liminix console=ttyS0,115200 panic=10 oops=panic init=/bin/init loglevel=8 root=/dev/ubi0_4 rootfstype=ubifs fw_devlink=off mtdparts=phram0:18M(rootfs) phram.phram=phram0,0x40400000,18874368,65536 root=/dev/mtdblock0");
parseopts(buf, &root, &rootfstype);
expect_equal(root, "/dev/mtdblock0");
expect_equal(rootfstype, "ubifs");
// options may appear in either order
buf = strdup("liminix fw_devlink=off root=/dev/hda1 rootfstype=ubifs foo");
parseopts(buf, &root, &rootfstype);
expect_equal(root, "/dev/hda1");
expect_equal(rootfstype, "ubifs");
buf = strdup("liminix rootfstype=ubifs fw_devlink=off root=/dev/hda1 foo");
parseopts(buf, &root, &rootfstype);
expect_equal(rootfstype, "ubifs");
expect_equal(root, "/dev/hda1");
// provides NULL for missing options
buf = strdup("liminix rufustype=ubifs fw_devlink=off foot=/dev/hda1");
parseopts(buf, &root, &rootfstype);
if(rootfstype) die("expected null rootfstype, got \"%s\"", rootfstype);
if(root) die("expected null root, got \"%s\"", root);
// provides empty strings for empty options
buf = strdup("liminix rootfstype= fw_devlink=off root= /dev/hda1");
parseopts(buf, &root, &rootfstype);
if(strlen(rootfstype)) die("expected empty rootfstype, got \"%s\"", rootfstype);
if(strlen(root)) die("expected null root, got \"%s\"", root);
expect_equal("01", pr_u32(1));
expect_equal("ab", pr_u32(0xab));
expect_equal("0abc", pr_u32(0xabc));
expect_equal("aabc", pr_u32(0xaabc));
expect_equal("deadcafe", pr_u32(0xdeadcafe));
}
#endif