Initial commit

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2024 Steve Markgraf
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

Makefile

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+CC = gcc
+CFLAGS = -g -Wall
+
+program : ms2130_patch.c
+	$(CC) $(CFLAGS) -o ms2130_patch ms2130_patch.c
+clean:
+	rm -f ms2130_patch

ms2130_patch.c

@@ -0,0 +1,165 @@
+/*
+ * MS2130 firmware patcher for optimized video quality
+ * Disables sharpening, scaling, etc.
+ *
+ * Copyright (C) 2024 by Steve Markgraf <steve@steve-m.de>
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <sys/stat.h>
+
+#define CODE_OFFSET	0x30
+#define CODE_CHECKSUM	0x09db
+
+/* Patch the firmware to disable scaler, sharpening etc., also see
+ * https://github.com/steve-m/hsdaoh/blob/21a4b470b4c079792034258304f6044bddc8abad/src/libhsdaoh.c#L205 */
+void patch_firmware(uint8_t *code)
+{
+	/* patch function call from clear_extmem_mask() to set_extmem_mask()
+	 * so that the result is:
+	 * set_extmem_mask(0xf6be, 0x11) */
+	code[0x9604] = 0xbf;
+	code[0x9605] = 0x44;
+
+	/* patch function call from clear_extmem_mask() to set_extmem_mask()
+	 * so that the result is:
+	 * set_extmem_mask(0xf6bf, 0x11) */
+	code[0x960d] = 0xbf;
+	code[0x960e] = 0x44;
+
+	/* patch function call from FUN_CODE_b8ad() to clear_extmem_mask()
+	 * so that the result is:
+	 * clear_extmem_mask(0xf6b0, 0x01) (clear bit 0) */
+	code[0xbe90] = 0x00;
+	code[0xbe91] = 0x06;
+
+	/* patch value of call to set_extmem_mask()
+	 * so that the result is:
+	 * set_extmem_mask(0xf600, 0x80) (set bit 7) */
+	code[0xbee8] = 0x80;
+
+	/* horizontal scaler config, patch out function call to calculation subroutine
+	 * and force disable of scaling */
+	code[0x937e] = 0x00; // NOP
+	code[0x937f] = 0x7e; // MOV R6
+	code[0x9380] = 0x10; // #0x10
+
+	/* vertical scaler config, patch out function call to calculation subroutine
+	 * and force disable of scaling */
+	code[0x9399] = 0x00; // NOP
+	code[0x939a] = 0x7e; // MOV R6
+	code[0x939b] = 0x10; // #0x10
+}
+
+uint16_t calculate_header_checksum(uint8_t *data, uint16_t len)
+{
+	uint32_t csum = 0;
+
+	for (int i = 0x02; i < len; i++) {
+		if ((i < 0x0c) || (i > 0x0f))
+			csum += data[i];
+	}
+
+	return csum & 0xffff;
+}
+
+uint16_t calculate_code_checksum(uint8_t *data, uint16_t len)
+{
+	uint32_t csum = 0;
+
+	for (int i = 0; i < len; i++)
+		csum += data[i];
+
+	return csum & 0xffff;
+}
+
+int main(int argc, char *argv[])
+{
+	FILE *fp = fopen("./4k2.bin", "rb");
+	if (!fp) {
+		printf("Error opening file\n");
+		goto err;
+	}
+
+	struct stat finfo;
+	fstat(fileno(fp), &finfo);
+	size_t file_len = finfo.st_size;
+
+	printf("Length of file: %ld\n", file_len);
+
+	uint8_t *fw = malloc(file_len);
+	if (fw) {
+		if (fread(fw, 1, file_len, fp) != file_len) {
+			printf("Error reading firmware file!\n");
+			goto err;
+		}
+		fclose(fp);
+	}
+
+	uint16_t code_len = (fw[0x02] << 8) | fw[0x03];
+	printf("Code length: %d\n", code_len);
+
+	uint16_t calc_header_csum = calculate_header_checksum(fw, CODE_OFFSET);
+	uint16_t orig_header_csum  = (fw[CODE_OFFSET + code_len + 0] << 8) | fw[CODE_OFFSET + code_len + 1];
+
+	if (calc_header_csum != orig_header_csum)
+		printf("Original header checksum mismatch: %04x != %04x\n", orig_header_csum, calc_header_csum);
+	else
+		printf("Original header checksum matches: %04x\n", orig_header_csum);
+
+	uint16_t calc_code_csum = calculate_code_checksum(fw + CODE_OFFSET, code_len);
+	uint16_t orig_code_csum  = (fw[CODE_OFFSET + code_len + 2] << 8) | fw[CODE_OFFSET + code_len + 3];
+
+	if (calc_code_csum != orig_code_csum)
+		printf("Original code checksum mismatch: %04x != %04x\n", orig_code_csum, calc_code_csum);
+	else
+		printf("Original code checksum matches: %04x\n", orig_code_csum);
+
+	if (CODE_CHECKSUM != calc_code_csum) {
+		printf("The code checksum does not match the firmware file this tool was written for, patch not applied!\n");
+		goto err;
+	}
+
+	patch_firmware(fw + CODE_OFFSET);
+
+	/* replace the code checksum */
+	calc_code_csum = calculate_code_checksum(fw + CODE_OFFSET, code_len);
+	fw[CODE_OFFSET + code_len + 2] = calc_code_csum >> 8;
+	fw[CODE_OFFSET + code_len + 3] = calc_code_csum & 0xff;
+
+	/* write the resulting file */
+	fp = fopen("./patched.bin", "wb");
+	fwrite(fw, 1, file_len, fp);
+
+err:
+	if (fp)
+		fclose(fp);
+
+	if (fw)
+		free(fw);
+
+	return 0;
+}