posix-uefi/examples/0D_memmap/memmap.c

#include <uefi.h>

/**
 * List memory map
 */
int main(int argc, char **argv)
{
    (void)argc;
    (void)argv;
    efi_status_t status;
    efi_memory_descriptor_t *memory_map = NULL, *mement;
    uintn_t memory_map_size=0, map_key=0, desc_size=0;
    const char *types[] = {
        "EfiReservedMemoryType",
        "EfiLoaderCode",
        "EfiLoaderData",
        "EfiBootServicesCode",
        "EfiBootServicesData",
        "EfiRuntimeServicesCode",
        "EfiRuntimeServicesData",
        "EfiConventionalMemory",
        "EfiUnusableMemory",
        "EfiACPIReclaimMemory",
        "EfiACPIMemoryNVS",
        "EfiMemoryMappedIO",
        "EfiMemoryMappedIOPortSpace",
        "EfiPalCode"
    };

    /* get the memory map */
    status = BS->GetMemoryMap(&memory_map_size, NULL, &map_key, &desc_size, NULL);
    if(status != EFI_BUFFER_TOO_SMALL || !memory_map_size) goto err;
    /* in worst case malloc allocates two blocks, and each block might split a record into three, that's 4 additional records */
    memory_map_size += 4 * desc_size;
    memory_map = (efi_memory_descriptor_t*)malloc(memory_map_size);
    if(!memory_map) {
        fprintf(stderr, "unable to allocate memory\n");
        return 1;
    }
    status = BS->GetMemoryMap(&memory_map_size, memory_map, &map_key, &desc_size, NULL);
    if(EFI_ERROR(status)) {
err:    fprintf(stderr, "Unable to get memory map\n");
        return 0;
    }

    printf("Address              Size Type\n");
    for(mement = memory_map; (uint8_t*)mement < (uint8_t*)memory_map + memory_map_size;
        mement = NextMemoryDescriptor(mement, desc_size)) {
            printf("%016x %8d %02x %s\n", mement->PhysicalStart, mement->NumberOfPages, mement->Type, types[mement->Type]);
    }

    free(memory_map);
    return 0;
}