Remove `r` in R.

    defaults: ["toolbox_binary_defaults"],

}

// We only want 'r' on userdebug and eng builds.

cc_binary {

    name: "r",

    defaults: ["toolbox_defaults"],

    srcs: ["r.c"],

    vendor_available: true,

}

// We build BSD grep separately (but see http://b/111849261).

cc_defaults {

    name: "grep_common",

#include <fcntl.h>

#include <inttypes.h>

#include <stdbool.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <sys/mman.h>

#include <unistd.h>

#if __LP64__

#define strtoptr strtoull

#else

#define strtoptr strtoul

#endif

static int usage()

{

    fprintf(stderr,"r [-b|-s] <address> [<value>]\n");

    return -1;

}

int main(int argc, char *argv[])

{

    if(argc < 2) return usage();

    int width = 4;

    if(!strcmp(argv[1], "-b")) {

        width = 1;

        argc--;

        argv++;

    } else if(!strcmp(argv[1], "-s")) {

        width = 2;

        argc--;

        argv++;

    }

    if(argc < 2) return usage();

    uintptr_t addr = strtoptr(argv[1], 0, 16);

    uintptr_t endaddr = 0;

    char* end = strchr(argv[1], '-');

    if (end)

        endaddr = strtoptr(end + 1, 0, 16);

    if (!endaddr)

        endaddr = addr + width - 1;

    if (endaddr <= addr) {

        fprintf(stderr, "end address <= start address\n");

        return -1;

    }

    bool set = false;

    uint32_t value = 0;

    if(argc > 2) {

        set = true;

        value = strtoul(argv[2], 0, 16);

    }

    int fd = open("/dev/mem", O_RDWR | O_SYNC);

    if(fd < 0) {

        fprintf(stderr,"cannot open /dev/mem\n");

        return -1;

    }

    off64_t mmap_start = addr & ~(PAGE_SIZE - 1);

    size_t mmap_size = endaddr - mmap_start + 1;

    mmap_size = (mmap_size + PAGE_SIZE - 1) & ~(PAGE_SIZE - 1);

    void* page = mmap64(0, mmap_size, PROT_READ | PROT_WRITE,

                        MAP_SHARED, fd, mmap_start);

    if(page == MAP_FAILED){

        fprintf(stderr,"cannot mmap region\n");

        return -1;

    }

    while (addr <= endaddr) {

        switch(width){

        case 4: {

            uint32_t* x = (uint32_t*) (((uintptr_t) page) + (addr & 4095));

            if(set) *x = value;

            fprintf(stderr,"%08"PRIxPTR": %08x\n", addr, *x);

            break;

        }

        case 2: {

            uint16_t* x = (uint16_t*) (((uintptr_t) page) + (addr & 4095));

            if(set) *x = value;

            fprintf(stderr,"%08"PRIxPTR": %04x\n", addr, *x);

            break;

        }

        case 1: {

            uint8_t* x = (uint8_t*) (((uintptr_t) page) + (addr & 4095));

            if(set) *x = value;

            fprintf(stderr,"%08"PRIxPTR": %02x\n", addr, *x);

            break;

        }

        }

        addr += width;

    }

    return 0;

}