Optimize the JEP106 list by switching from relocated string pointers to offsets from the beginning of a string table, defined in a generated file.

Typically saves > 1400 bytes on x86, > 4000 bytes on x86_64.

.gitignore

@@ -11,6 +11,7 @@
 build_version.h
 gdbscript
 memtest_shared_debug.lds
+jedec_id.h
 
 # Binaries
 memtest_shared
@@ -21,6 +22,7 @@ memtest_shared.bin
 *.iso
 *.mbr
 *.debug
+generate_jep106
 
 # Directories
 grub-iso

build32/Makefile

@@ -25,7 +25,7 @@ else
   MS_LDS=ldscripts/memtest_shared.lds
 endif
 
-INC_DIRS = -I../boot -I../system -I../lib -I../tests -I../app -Iapp
+INC_DIRS = -I../boot -I../system -Isystem -I../lib -I../tests -I../app -Iapp
 
 SYS_OBJS = system/acpi.o \
            system/cpuid.o \
@@ -36,6 +36,7 @@ SYS_OBJS = system/acpi.o \
            system/heap.o \
            system/hwctrl.o \
            system/hwquirks.o \
+           system/jedec_id.o \
            system/keyboard.o \
            system/ohci.o \
            system/memctrl.o \
@@ -120,7 +121,19 @@ system/reloc.o: ../system/reloc32.c
 	@mkdir -p system
 	$(CC) -c $(CFLAGS) -fno-strict-aliasing $(OPT_SMALL) $(INC_DIRS) -o $@ $< -MMD -MP -MT $@ -MF $(@:.o=.d)
 
-system/%.o: ../system/%.c
+tools/generate_jep106: ../tools/generate_jep106.c
+	@mkdir -p tools
+	$(CC) -std=c11 -Wall -Wextra -Wshadow -o $@ $<
+
+system/jedec_id.h: tools/generate_jep106
+	@mkdir -p system
+	$< > system/jedec_id.h 2> system/jedec_id.s
+
+system/jedec_id.o: system/jedec_id.h
+	@mkdir -p system
+	$(AS) system/jedec_id.s -o $@
+
+system/%.o: ../system/%.c system/jedec_id.h
 	@mkdir -p system
 	$(CC) -c $(CFLAGS) $(OPT_SMALL)  $(INC_DIRS) -o $@ $< -MMD -MP -MT $@ -MF $(@:.o=.d)
 
@@ -204,7 +217,7 @@ memtest.iso: memtest.mbr floppy.img esp.img
 iso: memtest.iso
 
 clean:
-	rm -rf boot system lib tests app *.img *.iso memtest* iso grub-*
+	rm -rf boot system lib tests app tools *.img *.iso memtest* iso grub-*
 
 # grub-memtest.iso uses GRUB as an intermediate bootloader to allow Memtest86+
 # to be started with the native USB keyboard drivers either enabled or disabled,

build64/Makefile

@@ -25,7 +25,7 @@ else
   MS_LDS=ldscripts/memtest_shared.lds
 endif
 
-INC_DIRS = -I../boot -I../system -I../lib -I../tests -I../app -Iapp
+INC_DIRS = -I../boot -I../system -Isystem -I../lib -I../tests -I../app -Iapp
 
 SYS_OBJS = system/acpi.o \
            system/cpuid.o \
@@ -33,9 +33,10 @@ SYS_OBJS = system/acpi.o \
            system/cpulocal.o \
            system/ehci.o \
            system/font.o \
-           system/hwctrl.o \
            system/heap.o \
+           system/hwctrl.o \
            system/hwquirks.o \
+           system/jedec_id.o \
            system/keyboard.o \
            system/ohci.o \
            system/memctrl.o \
@@ -119,7 +120,19 @@ system/reloc.o: ../system/reloc64.c
 	@mkdir -p system
 	$(CC) -c $(CFLAGS) -fno-strict-aliasing $(OPT_SMALL)  $(INC_DIRS)  -o $@ $< -MMD -MP -MT $@ -MF $(@:.o=.d)
 
-system/%.o: ../system/%.c
+tools/generate_jep106: ../tools/generate_jep106.c
+	@mkdir -p tools
+	$(CC) -std=c11 -Wall -Wextra -Wshadow -o $@ $<
+
+system/jedec_id.h: tools/generate_jep106
+	@mkdir -p system
+	$< > system/jedec_id.h 2> system/jedec_id.s
+
+system/jedec_id.o: system/jedec_id.h
+	@mkdir -p system
+	$(AS) system/jedec_id.s -o $@
+
+system/%.o: ../system/%.c system/jedec_id.h
 	@mkdir -p system
 	$(CC) -c $(CFLAGS) $(OPT_SMALL)  $(INC_DIRS)  -o $@ $< -MMD -MP -MT $@ -MF $(@:.o=.d)
 
@@ -203,7 +216,7 @@ memtest.iso: memtest.mbr floppy.img esp.img
 iso: memtest.iso
 
 clean:
-	rm -rf boot system lib tests app *.img *.iso memtest* iso grub-*
+	rm -rf boot system lib tests app tools *.img *.iso memtest* iso grub-*
 
 # grub-memtest.iso uses GRUB as an intermediate bootloader to allow Memtest86+
 # to be started with the native USB keyboard drivers either enabled or disabled,

system/spd.c

@@ -53,7 +53,7 @@ void print_spdi(spd_info spdi, uint8_t row)
     // Print Manufacturer from JEDEC106
     for (i = 0; i < JEP106_CNT; i++) {
         if (spdi.jedec_code == jep106[i].jedec_code) {
-            curcol = printf(row, ++curcol, "- %s", jep106[i].name);
+            curcol = printf(row, ++curcol, "- %s", JEP106_NAME(i));
             break;
         }
     }

tools/generate_jep106.c

@@ -1,14 +1,16 @@
 /* MemTest86+ V5 Specific code (GPL V2.0)
  * By Samuel DEMEULEMEESTER, memtest@memtest.org
  * https://x86.fr - https://www.memtest.org
+ *
+ * Generator by Lionel Debroux, lionel_debroux@yahoo.fr
  * ------------------------------------------------
  * Based on JEDEC JEP106-BA - January 2022
  */
 
-#define JEDEC_CONT_CODE_MAX 14
+#include <stddef.h>
-
+#include <stdio.h>
-#define JEP106_CNT \
+#include <stdlib.h>
-    sizeof(jep106)/sizeof(jep106[0])
+#include <stdint.h>
 
 struct __attribute__((packed)) spd_jedec_manufacturer {
     uint16_t jedec_code;
@@ -1682,3 +1684,56 @@ static const struct __attribute__((packed)) spd_jedec_manufacturer jep106[] = {
     { 0x0F33, "Xllbyte" },
     { 0xFFFF, "Unknown"}
 };
+
+#define STR_SIZE (16384)
+
+int main(int argc, char ** argv) {
+    (void)argc, (void)argv;
+
+    char structstr[STR_SIZE];
+    char stringstr[STR_SIZE];
+    char idstr[5];
+
+    char * ptr1 = structstr;
+    char * ptr2 = stringstr;
+
+    for (size_t i = 0; i < sizeof(jep106) / sizeof(jep106[0]); i++) {
+        int written;
+        sprintf(idstr, "%04X", jep106[i].jedec_code);
+        written = sprintf(ptr1, "\t\t.dc.w 0x%s\n\t\t.dc.w jep106_str_%s - jep106_str_start\n", idstr, idstr);
+        ptr1 += written;
+        written = sprintf(ptr2, "jep106_str_%s:\n\t.asciz \"%s\"\n", idstr, jep106[i].name);
+        ptr2 += written;
+    }
+
+    fprintf(stderr,
+"\t.section \".rodata\", \"a\", @progbits\n\t.globl jep106_str_start\njep106_str_start:\n%s\n"
+"\t.balign 2\n\t.globl jep106\njep106:\n%s",
+            stringstr, structstr);
+
+    fprintf(stdout,
+"/* MemTest86+ V5 Specific code (GPL V2.0)\n"
+" * By Samuel DEMEULEMEESTER, memtest@memtest.org\n"
+" * https://x86.fr - https://www.memtest.org\n"
+" * ------------------------------------------------\n"
+" * Based on JEDEC JEP106-BA - January 2022\n"
+" */\n"
+"\n"
+"#define JEDEC_CONT_CODE_MAX 14\n"
+"\n"
+"struct spd_jedec_manufacturer {\n"
+"    uint16_t jedec_code;\n"
+"    uint16_t offset;\n"
+"};\n"
+"\n"
+"extern const char jep106_str_start;\n"
+"extern const struct spd_jedec_manufacturer jep106[];\n"
+"\n"
+"#define JEP106_CNT (%zu)\n"
+"\n"
+"#define JEP106_NAME(i) \\\n"
+"    (&jep106_str_start + jep106[i].offset)\n",
+            sizeof(jep106) / sizeof(jep106[0]));
+
+    return 0;
+}