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-rw-r--r--tools/br_ips/br_ips.c321
1 files changed, 321 insertions, 0 deletions
diff --git a/tools/br_ips/br_ips.c b/tools/br_ips/br_ips.c
new file mode 100644
index 0000000..64c454a
--- /dev/null
+++ b/tools/br_ips/br_ips.c
@@ -0,0 +1,321 @@
+#define _POSIX_C_SOURCE 200808L // Don't use GNU getline
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <string.h>
+#include "global.h"
+
+static const char SPLASH[] = "IPS patch creator for undisassembled data\n"
+ "Created by PikalaxALT on 23 June 2019 All Rights Reserved\n";
+
+static const char HELP[] = "br_ips\n"
+ "This utility is meant to be run with no arguments in the project root of a PRET AGB disassembly.\n"
+ "baserom.gba and ld_script.txt are required files which must be present in the project root.\n"
+ "ld_script.txt is a GNU linker script. For more details, see\n"
+ "https://ftp.gnu.org/old-gnu/Manuals/ld-2.9.1/html_chapter/ld_3.html#SEC6.\n"
+ "All ELF targets in the linker script with Makefile rules \"%.o: %.s\" must have their sources present\n"
+ "at the indicated paths relative to the project root.\n"
+ "\n"
+ "Options:\n"
+ " -h - show this message and exit\n";
+
+static int getline(char ** lineptr, size_t * n, FILE * stream) {
+ // Static implementation of GNU getline
+ int i = 0;
+ int c;
+ if (n == NULL || lineptr == NULL || stream == NULL) return -1;
+ size_t size = *n;
+ char * buf = *lineptr;
+ if (buf == NULL || size < 4) {
+ size = 128;
+ *lineptr = buf = realloc(buf, 128);
+ }
+ if (buf == NULL) return -1;
+ while (1) {
+ c = getc(stream);
+ if (c == EOF) break;
+ buf[i++] = c;
+ if (c == '\n') break;
+ if (i == size - 1) {
+ size <<= 1;
+ buf = realloc(buf, size);
+ if (buf == NULL) return -1;
+ *lineptr = buf;
+ *n = size;
+ }
+ }
+ if (i == 0) return -1;
+ buf[i] = 0;
+ return i;
+}
+
+static void getIncbinsFromFile(hunk_t ** hunks, size_t * num, size_t * maxnum, const char * fname, char ** strbuf, size_t * buffersize) {
+ // Recursively find incbinned segments and encode them as hunks.
+ FILE * file = fopen(fname, "r");
+ if (file == NULL) FATAL_ERROR("unable to open file \"%s\" for reading\n", fname);
+ hunk_t * data = *hunks;
+ size_t nhunks = *num;
+ size_t maxnhunks = *maxnum;
+ int line_n = 0; // for error prints
+ while (getline(strbuf, buffersize, file) > 0) {
+ line_n++;
+ // If another file is included by this one, recurse into it.
+ char * include = strstr(*strbuf, ".include");
+ if (include != NULL) {
+ char incfname[128];
+ include = strchr(include, '"');
+ if (include == NULL) FATAL_ERROR("%s:%d: malformed include\n", fname, line_n);
+ include++;
+ char * endq_p = strchr(include, '"');
+ if (endq_p == NULL) FATAL_ERROR("%s:%d: malformed include\n", fname, line_n);
+ *endq_p = 0;
+ strcpy(incfname, include);
+ getIncbinsFromFile(&data, &nhunks, &maxnhunks, incfname, strbuf, buffersize);
+ continue;
+ }
+ // Check for a .incbin "baserom.gba" directive
+ char * line = strstr(*strbuf, ".incbin");
+ if (line == NULL) continue;
+ line = strstr(line + sizeof(".incbin"), "\"baserom.gba\",");
+ if (line == NULL) continue;
+ line += sizeof("\"baserom.gba\",") - 1;
+ uint32_t incbinOffset;
+ // Enforce the structure .incbin "baserom.gba", offset, size
+ // Data cannot be located at offset 0, as that is the entry
+ // point (ARM code).
+ do {
+ if (*line == 0) FATAL_ERROR("%s:%d: malformed incbin\n", fname, line_n);
+ incbinOffset = strtoul(line, &line, 0);
+ line++;
+ } while (incbinOffset == 0);
+ size_t incbinSize;
+ do {
+ if (*line == 0) FATAL_ERROR("%s:%d: malformed incbin\n", fname, line_n);
+ incbinSize = strtoul(line, &line, 0);
+ line++;
+ } while (incbinSize == 0);
+ // Offset must fit in three bytes
+ if (incbinOffset >= 0x01000000) FATAL_ERROR("%s:%d: offset exceeds encodable limit\n", fname, line_n);
+ // Avoid confusion with the end sentinel
+ if (incbinOffset == 0x454F46) { // "EOF"
+ incbinOffset--;
+ incbinSize++;
+ }
+ // Cannot read past a certain point due to format restrictions
+ if (incbinOffset + incbinSize > 0xFFFFFF + 0xFFFF) FATAL_ERROR("%s:%d: size exceeds encodable limit\n", fname, line_n);
+ // Break up the incbin into hunks of maximum size 0xFFFF
+ do {
+ size_t trueSize = incbinSize <= 0xFFFF ? incbinSize : 0xFFFF;
+ if (nhunks >= maxnhunks) {
+ maxnhunks <<= 1;
+ data = realloc(data, maxnhunks * sizeof(hunk_t));
+ if (data == NULL) FATAL_ERROR("unable to reallocate hunks buffer\n");
+ }
+ data[nhunks].offset = incbinOffset;
+ data[nhunks].size = trueSize;
+ incbinOffset += trueSize;
+ incbinSize -= trueSize;
+ if (incbinOffset == 0x454F46) {
+ incbinOffset--;
+ data[nhunks].size--;
+ incbinSize++;
+ }
+ nhunks++;
+ } while (incbinSize > 0);
+ }
+ // Error check
+ if (!feof(file)) FATAL_ERROR("getline\n");
+ fclose(file);
+ *hunks = data;
+ *num = nhunks;
+ *maxnum = maxnhunks;
+}
+
+static hunk_t * getAllIncbins(FILE * ld_script, size_t * num_p) {
+ // Parse the ld script.
+ // Strict adherence to syntax is expected.
+ char * line = NULL;
+ size_t linesiz = 0;
+ char fname_buf[128];
+ size_t maxnum = 256;
+ size_t num = 0;
+ // Allocate the hunks array.
+ hunk_t * hunks = malloc(256 * sizeof(hunk_t));
+ if (hunks == NULL) FATAL_ERROR("failed to allocate hunks buffer\n");
+ while (getline(&line, &linesiz, ld_script) > 0) {
+ char * endptr;
+ // We only expect hunks in rodata, script_data, and gfx_data sections.
+ if ((endptr = strstr(line, ".o(.rodata);")) == NULL
+ && (endptr = strstr(line, ".o(script_data);")) == NULL
+ && (endptr = strstr(line, ".o(gfx_data);")) == NULL) continue;
+ char * startptr = line;
+ // Skip whitespace.
+ while (isspace(*startptr)) startptr++;
+ if (strstr(startptr, ".a:") != NULL) continue; // no hunks in libs
+ if (strstr(startptr, "src/") == startptr) continue; // no hunks in src/
+ // Replace the extension with .s and truncate the string
+ endptr[1] = 's';
+ endptr[2] = 0;
+ // We're reusing the already-allocated string buffer, so
+ // copy the filename to the stack for use in error prints.
+ strcpy(fname_buf, startptr);
+ getIncbinsFromFile(&hunks, &num, &maxnum, fname_buf, &line, &linesiz);
+ }
+ // Error check
+ if (!feof(ld_script)) FATAL_ERROR("getline\n");
+ free(line);
+ *num_p = num;
+ return hunks;
+}
+
+static int cmp_baserom(const void * a, const void * b) {
+ // Comparison function for sorting Hunk structs.
+ // For more details, please refer to the qsort man pages.
+ // See also the function "collapseIncbins" below.
+ const hunk_t * aa = (const hunk_t *)a;
+ const hunk_t * bb = (const hunk_t *)b;
+ return (aa->offset > bb->offset) - (aa->offset < bb->offset);
+}
+
+static void collapseIncbins(hunk_t * hunks, size_t * num_p) {
+ // This function merges adjacent hunks where possible.
+ size_t num = *num_p;
+ // Sort the array by offset increasing.
+ qsort(hunks, num, sizeof(hunk_t), cmp_baserom);
+ // We stop at num - 1 because we need to be able to look one
+ // entry ahead in the hunks array.
+ for (int i = 0; i < num - 1; i++) {
+ // Loop until the next hunk is not adjacent to the current.
+ while (hunks[i].offset + hunks[i].size == hunks[i + 1].offset) {
+ // If this hunk cannot be merged with the next, proceed to the next.
+ if (hunks[i].size == 0xFFFF || (hunks[i].size == 0xFFFE && hunks[i + 1].offset == 0x454F45)) break;
+ // If this hunk is empty, remove it.
+ if (hunks[i].size == 0) {
+ int j;
+ // Find the next non-empty hunk
+ for (j = i + 1; j < num; j++) {
+ if (hunks[j].size != 0) break;
+ }
+ if (j == num) {
+ // All remaining hunks are empty
+ num = i;
+ break;
+ }
+ // Compaction
+ // Use a for loop instead of memcpy to avoid UB from
+ // overlapping buffers.
+ for (int k = 0; k < num - j; k++) hunks[i + k] = hunks[j + k];
+ num -= j - i;
+ if (i >= num - 1) break;
+ }
+ else
+ {
+ // Combine this hunk with the next
+ hunks[i].size += hunks[i + 1].size;
+ if (hunks[i].size > 0xFFFF) {
+ // Split the hunk back up, it's too big to encode.
+ // Set the earlier hunk to the maximum permitted size,
+ // and the following hunk to the remainder.
+ hunks[i + 1].size = hunks[i].size - 0xFFFF;
+ hunks[i].size = 0xFFFF;
+ hunks[i + 1].offset = hunks[i].offset + 0xFFFF;
+ // If this operation would confuse the hunk with the
+ // EOF sentinel, fix that.
+ if (hunks[i + 1].offset == 0x454F46) {
+ hunks[i].size--;
+ hunks[i + 1].offset--;
+ hunks[i + 1].size++;
+ }
+ break;
+ } else {
+ // Compaction
+ // Use a for loop instead of memcpy to avoid UB from
+ // overlapping buffers.
+ for (int j = i + 1; j < num - 1; j++) hunks[j] = hunks[j + 1];
+ num--;
+ if (i >= num - 1) break;
+ }
+ }
+ }
+ }
+ *num_p = num;
+}
+
+static void writePatch(const char * filename, const hunk_t * hunks, size_t num, FILE * rom) {
+ // Create an IPS patch.
+ // The file is headed with a magic code which is "PATCH" in ASCII.
+ // Following that are the "hunks": 3-byte offset, 2-byte size, and
+ // the literal data. The file is ended with "EOF", again in ASCII.
+ // For that reason, an offset of 0x454F46 cannot be encoded directly.
+ // Offset and size are encoded big-endian.
+ FILE * file = fopen(filename, "wb");
+ if (file == NULL) FATAL_ERROR("unable to open file \"%s\" for writing\n", filename);
+ // Maximum hunk size is 65535 bytes. For convenience, we allocate a
+ // round 65536 (0x10000). This has no effect on memory consumption,
+ // as malloc will round this up anyway.
+ char * readbuf = malloc(0x10000);
+ if (readbuf == NULL) FATAL_ERROR("failed to allocate write buffer\n");
+ fwrite("PATCH", 1, 5, file); // magic
+ for (int i = 0; i < num; i++) {
+ // Encode the offset
+ uint32_t offset = hunks[i].offset;
+ putc(offset >> 16, file);
+ putc(offset >> 8, file);
+ putc(offset >> 0, file);
+ // Encode the size
+ size_t size = hunks[i].size;
+ putc(size >> 8, file);
+ putc(size >> 0, file);
+ // Yank the data straight from the ROM
+ if (fseek(rom, offset, SEEK_SET)) FATAL_ERROR("seek\n");
+ if (fread(readbuf, 1, size, rom) != size) FATAL_ERROR("read\n");
+ if (fwrite(readbuf, 1, size, file) != size) FATAL_ERROR("write\n");
+ }
+ free(readbuf);
+ // Write the EOF magic
+ fwrite("EOF", 1, 3, file);
+ fclose(file);
+}
+
+// This script takes no arguments.
+int main(int argc, char ** argv) {
+ // Show a friendly message
+ puts(SPLASH);
+ // If requested, show help message
+ if (argc >= 2 && strcmp(argv[1], "-h") == 0) {
+ puts(HELP);
+ return 0;
+ }
+ // This script expects to be in a PRET AGB disassembly project root.
+ // Required files include baserom.gba, ld_script.txt, and all paths
+ // referenced in ld_script.txt relative to the project root.
+ FILE * rom = fopen("baserom.gba", "rb");
+ if (rom == NULL) FATAL_ERROR("unable to open \"baserom.gba\" for reading\n");
+ FILE * ld_script = fopen("ld_script.txt", "r");
+ if (ld_script == NULL) FATAL_ERROR("unable to open \"ld_script.txt\" for reading\n");
+ // Find all instances where segments of baserom.gba are incbinned literaly.
+ size_t num = 0;
+ hunk_t * hunks = getAllIncbins(ld_script, &num);
+ fclose(ld_script);
+ if (num == 0) {
+ // If this line is printed, the script was unable to find any
+ // `.incbin "baserom.gba"` lines.
+ // If this is incorrect, please contact the developer.
+ puts("No baserom.gba hunks found!\n"
+ "If there are baserom.gba hunks in this project,\n"
+ "please ping PikalaxALT on the pret discord,\n"
+ "channel #gen-3-help.\n");
+ } else {
+ // Merge neighboring hunks to reduce the number of hunks.
+ collapseIncbins(hunks, &num);
+ // Encode the hunks in the IPS patch.
+ writePatch("baserom.ips", hunks, num, rom);
+ // Communicate status to the user.
+ puts("IPS file created at baserom.ips\n");
+ }
+ // Clean up and return.
+ fclose(rom);
+ free(hunks);
+ return 0;
+}
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