Added PMP checker submission

submissions/hamza-1821/pmp_checker.c

@@ -0,0 +1,141 @@
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#define MAX_LINES 64
+
+// PMP configuration arrays
+uint8_t config_array[MAX_LINES];   // Stores PMP configurations
+uint32_t address_array[MAX_LINES]; // Stores PMP address regions
+
+// Function to read the PMP configuration file
+void read_config_file(const char *filename, uint8_t *config_array, uint32_t *address_array) {
+    FILE *file = fopen(filename, "r");
+    if (file == NULL) {
+        printf("Error: Could not open configuration file.\n");
+        exit(1);
+    }
+
+    char line[256];
+
+    // Read the first 64 lines into config_array
+    for (int i = 0; i < MAX_LINES; i++) {
+        if (fgets(line, sizeof(line), file) == NULL) {
+            printf("Error: Unexpected EOF while reading config at line %d.\n", i + 1);
+            exit(1);
+        }
+        unsigned int value;
+        sscanf(line, "%x", &value);
+        config_array[i] = (uint8_t)value;
+    }
+
+    // Read the next 64 lines into address_array
+    for (int i = 0; i < MAX_LINES; i++) {
+        if (fgets(line, sizeof(line), file) == NULL) {
+            printf("Error: Unexpected EOF while reading addresses at line %d.\n", i + 1);
+            exit(1);
+        }
+        unsigned int value;
+        sscanf(line, "%x", &value);
+        address_array[i] = value;
+    }
+
+    fclose(file);
+}
+
+// Function to compute NAPOT range
+void compute_napot_range(uint32_t addr, uint32_t *base, uint32_t *limit) {
+    // If no trailing ones, it is a single address range (NA4)
+    if ((addr & 1) == 0) {
+        *base = addr;
+        *limit = addr + 4;  // NA4 region
+        return;
+    }
+
+    // Count trailing ones for NAPOT
+    int count = 0;
+    uint32_t temp = addr;
+    while (temp & 1) {
+        count++;
+        temp >>= 1;
+    }
+
+    uint32_t size = 1 << (count + 2);
+    *base = addr & ~(size - 1);
+    *limit = *base + size;
+}
+
+// Function to check PMP access
+void pmp_check(uint8_t *config_array, uint32_t *address_array, uint32_t addr, char operation) {
+    for (int j = 0; j < MAX_LINES; j++) {
+        uint32_t region_addr = address_array[j];
+        uint8_t config = config_array[j];
+
+        uint8_t R = config & 1;
+        uint8_t W = (config >> 1) & 1;
+        uint8_t X = (config >> 2) & 1;
+        uint8_t A = (config >> 3) & 3;  // Extract A field (bits 3-4)
+
+        printf("Region %d: A-Field = %d, Config = 0x%X, Address = 0x%X\n", j, A, config, region_addr);
+
+        // Check the type of region
+        if (A == 0) {
+            printf("Region %d: PMP Disabled\n", j);
+            continue;
+        }
+
+        uint32_t base = 0, limit = 0;
+
+        if (A == 3) {  // NAPOT
+            compute_napot_range(region_addr, &base, &limit);
+            printf("Region %d: NAPOT Mode, Base = 0x%X, Limit = 0x%X\n", j, base, limit);
+        } else if (A == 1) {  // TOR
+            if (j == 0) {
+                base = 0;  // First TOR region starts at 0
+            } else {
+                base = address_array[j - 1];
+            }
+            limit = region_addr;
+            printf("Region %d: TOR Mode, Base = 0x%X, Limit = 0x%X\n", j, base, limit);
+        } else if (A == 2) {  // NA4
+            base = region_addr;
+            limit = region_addr + 4;
+            printf("Region %d: NA4 Mode, Base = 0x%X, Limit = 0x%X\n", j, base, limit);
+        }
+
+        // Check if the address falls within the region
+        if (base <= addr && addr < limit) {
+            if ((operation == 'R' && R) || (operation == 'W' && W) || (operation == 'X' && X)) {
+                printf("Access Granted: Address 0x%X in region %d\n", addr, j);
+                return;
+            } else {
+                printf("Access Fault: Address 0x%X in region %d\n", addr, j);
+                return;
+            }
+        }
+    }
+
+    // Default case: No matching region found
+    printf("Access Fault: Address 0x%X (No PMP region found)\n", addr);
+}
+
+// Main function to take user input and run PMP check
+int main(int argc, char *argv[]) {
+    if (argc != 4) {
+        printf("Usage: %s <config_file> <address> <operation>\n", argv[0]);
+        printf("Example: %s configurations.txt 0x80001000 R\n", argv[0]);
+        return 1;
+    }
+
+    const char *config_file = argv[1];
+    uint32_t addr = strtoul(argv[2], NULL, 16);
+    char operation = argv[3][0];
+
+    // Read PMP configuration
+    read_config_file(config_file, config_array, address_array);
+
+    // Perform PMP check
+    pmp_check(config_array, address_array, addr, operation);
+
+    return 0;
+}