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Further optimization for space (-Os -> -Oz): musl-cross-make-> bump to gcc 15.1.0 & related changes
WiP : bump musl-cross-make to latest commit, bump gcc 9.4.0 -> 15.1.0; rename/bump kexec-tools to latest version + gcc 15.10, switch/patch modules to switch from -Os to -Oz
TLDR: 1.44% space reduction (115kb gain)
Stats from global to specifics:
coreboot final stiching stats diff
"/home/user/heads/build/x86/coreboot-24.12/EOL_x230-hotp-maximized/cbfstool" "/home/user/heads/build/x86/coreboot-24.12/EOL_x230-hotp-maximized/coreboot.rom" print
FMAP REGION: COREBOOT
Name Offset Type Size Comp
cbfs_master_header 0x0 cbfs header 32 none
cpu_microcode_blob.bin 0x80 microcode 26624 none
fallback/romstage 0x68c0 stage 107512 none
fallback/ramstage 0x20d40 stage 149993 LZMA (324488 decompressed)
config 0x45780 raw 3521 LZMA (11135 decompressed)
revision 0x46580 raw 724 none
build_info 0x46880 raw 101 none
bootsplash.jpg 0x46940 bootsplash 43282 none
fallback/dsdt.aml 0x51280 raw 14748 none
vbt.bin 0x54c80 raw 1433 LZMA (4281 decompressed)
cmos_layout.bin 0x55280 cmos_layout 2012 none
fallback/postcar 0x55ac0 stage 40156 none
fallback/payload 0x5f800 simple elf 7908858 none
(empty) 0x7ea640 null 4048740 none
bootblock 0xbc6dc0 bootblock 36864 none
Master:
Jul 28 03:19:40 EOL_x230-hotp-maximized/util/cbfstool/cbfstool EOL_x230-hotp-maximized/coreboot.rom print -r COREBOOT
Jul 28 03:19:40 FMAP REGION: COREBOOT
Jul 28 03:19:40 Name Offset Type Size Comp
Jul 28 03:19:40 cbfs_master_header 0x0 cbfs header 32 none
Jul 28 03:19:40 cpu_microcode_blob.bin 0x80 microcode 26624 none
Jul 28 03:19:40 fallback/romstage 0x68c0 stage 107512 none
Jul 28 03:19:40 fallback/ramstage 0x20d40 stage 149982 LZMA (324488 decompressed)
Jul 28 03:19:40 config 0x45780 raw 3521 LZMA (11135 decompressed)
Jul 28 03:19:40 revision 0x46580 raw 724 none
Jul 28 03:19:40 build_info 0x46880 raw 101 none
Jul 28 03:19:40 bootsplash.jpg 0x46940 bootsplash 43282 none
Jul 28 03:19:40 fallback/dsdt.aml 0x51280 raw 14748 none
Jul 28 03:19:40 vbt.bin 0x54c80 raw 1433 LZMA (4281 decompressed)
Jul 28 03:19:40 cmos_layout.bin 0x55280 cmos_layout 2012 none
Jul 28 03:19:40 fallback/postcar 0x55ac0 stage 40156 none
Jul 28 03:19:40 fallback/payload 0x5f800 simple elf 8024362 none
Jul 28 03:19:40 (empty) 0x806980 null 3933220 none
Jul 28 03:19:40 bootblock 0xbc6dc0 bootblock 36864 none
Analysis:
- gain (emtpy comparison) = 4048740 - 3933220 = 115520 bytes
sizes.txt comparison (diff -u master pr)
--- /tmp/master_sizes.txt 2025-07-27 23:19:45.000000000 -0400
+++ build/x86/EOL_x230-hotp-maximized/sizes.txt 2025-07-30 12:22:53.607423022 -0400
-2025-07-28 03:11:34+00:00 652eff3d831aaf195825e55903cbc4fab67d4a56 clean
- 2822912:/root/heads/build/x86/EOL_x230-hotp-maximized/bzImage
- 930816:/root/heads/build/x86/EOL_x230-hotp-maximized/modules.cpio
+2025-07-30 16:19:56+00:00 b5a94d5488287500316e4de1072a6fba41d593b9 clean
+ 2798032:/home/user/heads/build/x86/EOL_x230-hotp-maximized/bzImage
+ 928256:/home/user/heads/build/x86/EOL_x230-hotp-maximized/modules.cpio
[...]
-13865984:/root/heads/build/x86/EOL_x230-hotp-maximized/tools.cpio
+13262336:/home/user/heads/build/x86/EOL_x230-hotp-maximized/tools.cpio
[...]
- 434176:/root/heads/build/x86/EOL_x230-hotp-maximized/heads.cpio
+ 434176:/home/user/heads/build/x86/EOL_x230-hotp-maximized/heads.cpio
[...]
- 2508800:/root/heads/build/x86/EOL_x230-hotp-maximized/data.cpio
+ 2508800:/home/user/heads/build/x86/EOL_x230-hotp-maximized/data.cpio
[...]
- 5212160:build/x86/EOL_x230-hotp-maximized/initrd.cpio.xz
+ 5121536:build/x86/EOL_x230-hotp-maximized/initrd.cpio.xz
Analysis:
- initrd.cpio.xz (concatenated+compressed cpio) reduced by 90,624 bytes (compression gains maybe suboptimal?)
- modules.cpio (kernel modules) reduced by 2,560 bytes
- tools.cpio (compiled libs/bins) reduced by 603,648 bytes
- bzImage (kernel) reduced by 24,880 bytes
TLDR:
- Master Heads payload: 8,035,072 bytes (7.66 MB)
- PR Heads payload: 7,919,568 bytes (7.55 MB) Total Savings: 115,504 bytes (1.44% reduction)
Continues #590
