Add bootloader configs to archiso profile (syslinux/efiboot/grub)

The profile declared syslinux + systemd-boot bootmodes but lacked the
required config directories, so mkarchiso would fail. Added from the
official releng profile, rebranded to Bread OS; %PLACEHOLDER% tokens are
substituted by mkarchiso at build time.

iso/syslinux/archiso_head.cfg

@@ -0,0 +1,28 @@
+SERIAL 0 115200
+UI vesamenu.c32
+MENU TITLE Bread OS
+MENU BACKGROUND splash.png
+
+MENU WIDTH 78
+MENU MARGIN 4
+MENU ROWS 7
+MENU VSHIFT 10
+MENU TABMSGROW 14
+MENU CMDLINEROW 14
+MENU HELPMSGROW 16
+MENU HELPMSGENDROW 29
+
+# Refer to https://wiki.syslinux.org/wiki/index.php/Comboot/menu.c32
+
+MENU COLOR border       30;44   #40ffffff #a0000000 std
+MENU COLOR title        1;36;44 #9033ccff #a0000000 std
+MENU COLOR sel          7;37;40 #e0ffffff #20ffffff all
+MENU COLOR unsel        37;44   #50ffffff #a0000000 std
+MENU COLOR help         37;40   #c0ffffff #a0000000 std
+MENU COLOR timeout_msg  37;40   #80ffffff #00000000 std
+MENU COLOR timeout      1;37;40 #c0ffffff #00000000 std
+MENU COLOR msg07        37;40   #90ffffff #a0000000 std
+MENU COLOR tabmsg       31;40   #30ffffff #00000000 std
+
+MENU CLEAR
+MENU IMMEDIATE

iso/syslinux/archiso_pxe-linux.cfg

@@ -0,0 +1,32 @@
+LABEL arch_nbd
+TEXT HELP
+Boot the Bread OS install medium using NBD.
+It allows you to install Bread OS or perform system maintenance.
+ENDTEXT
+MENU LABEL Bread OS install medium (%ARCH%, NBD)
+LINUX ::/%INSTALL_DIR%/boot/%ARCH%/vmlinuz-linux
+INITRD ::/%INSTALL_DIR%/boot/%ARCH%/initramfs-linux.img
+APPEND archisobasedir=%INSTALL_DIR% archisosearchuuid=%ARCHISO_UUID% archiso_nbd_srv=${pxeserver} cms_verify=y
+SYSAPPEND 3
+
+LABEL arch_nfs
+TEXT HELP
+Boot the Bread OS live medium using NFS.
+It allows you to install Bread OS or perform system maintenance.
+ENDTEXT
+MENU LABEL Bread OS install medium (%ARCH%, NFS)
+LINUX ::/%INSTALL_DIR%/boot/%ARCH%/vmlinuz-linux
+INITRD ::/%INSTALL_DIR%/boot/%ARCH%/initramfs-linux.img
+APPEND archisobasedir=%INSTALL_DIR% archiso_nfs_srv=${pxeserver}:/run/archiso/bootmnt cms_verify=y
+SYSAPPEND 3
+
+LABEL arch_http
+TEXT HELP
+Boot the Bread OS live medium using HTTP.
+It allows you to install Bread OS or perform system maintenance.
+ENDTEXT
+MENU LABEL Bread OS install medium (%ARCH%, HTTP)
+LINUX ::/%INSTALL_DIR%/boot/%ARCH%/vmlinuz-linux
+INITRD ::/%INSTALL_DIR%/boot/%ARCH%/initramfs-linux.img
+APPEND archisobasedir=%INSTALL_DIR% archiso_http_srv=http://${pxeserver}/ cms_verify=y
+SYSAPPEND 3

iso/syslinux/archiso_pxe.cfg

@@ -0,0 +1,5 @@
+INCLUDE archiso_head.cfg
+
+INCLUDE archiso_pxe-linux.cfg
+
+INCLUDE archiso_tail.cfg

iso/syslinux/archiso_sys-linux.cfg

@@ -0,0 +1,20 @@
+LABEL arch
+TEXT HELP
+Boot the Bread OS install medium on BIOS.
+It allows you to install Bread OS or perform system maintenance.
+ENDTEXT
+MENU LABEL Bread OS install medium (%ARCH%, BIOS)
+LINUX /%INSTALL_DIR%/boot/%ARCH%/vmlinuz-linux
+INITRD /%INSTALL_DIR%/boot/%ARCH%/initramfs-linux.img
+APPEND archisobasedir=%INSTALL_DIR% archisosearchuuid=%ARCHISO_UUID%
+
+# Accessibility boot option
+LABEL archspeech
+TEXT HELP
+Boot the Bread OS install medium on BIOS with speakup screen reader.
+It allows you to install Bread OS or perform system maintenance with speech feedback.
+ENDTEXT
+MENU LABEL Bread OS install medium (%ARCH%, BIOS) with ^speech
+LINUX /%INSTALL_DIR%/boot/%ARCH%/vmlinuz-linux
+INITRD /%INSTALL_DIR%/boot/%ARCH%/initramfs-linux.img
+APPEND archisobasedir=%INSTALL_DIR% archisosearchuuid=%ARCHISO_UUID% accessibility=on

iso/syslinux/archiso_sys.cfg

@@ -0,0 +1,8 @@
+INCLUDE archiso_head.cfg
+
+DEFAULT arch
+TIMEOUT 150
+
+INCLUDE archiso_sys-linux.cfg
+
+INCLUDE archiso_tail.cfg

iso/syslinux/archiso_tail.cfg

@@ -0,0 +1,35 @@
+LABEL existing
+TEXT HELP
+Boot an existing operating system.
+Press TAB to edit the disk and partition number to boot.
+ENDTEXT
+MENU LABEL Boot existing OS
+COM32 chain.c32
+APPEND hd0 0
+
+# https://www.memtest.org/
+LABEL memtest
+MENU LABEL Run Memtest86+ (RAM test)
+LINUX /boot/memtest86+/memtest
+
+# https://wiki.syslinux.org/wiki/index.php/Hdt_(Hardware_Detection_Tool)
+LABEL hdt
+MENU LABEL Hardware Information (HDT)
+COM32 hdt.c32
+APPEND modules_alias=hdt/modalias.gz pciids=hdt/pciids.gz
+
+LABEL reboot
+TEXT HELP
+Reboot computer.
+The computer's firmware must support APM.
+ENDTEXT
+MENU LABEL Reboot
+COM32 reboot.c32
+
+LABEL poweroff
+TEXT HELP
+Power off computer.
+The computer's firmware must support APM.
+ENDTEXT
+MENU LABEL Power Off
+COM32 poweroff.c32

iso/syslinux/syslinux.cfg

@@ -0,0 +1,11 @@
+DEFAULT select
+
+LABEL select
+COM32 whichsys.c32
+APPEND -pxe- pxe -sys- sys -iso- sys
+
+LABEL pxe
+CONFIG archiso_pxe.cfg
+
+LABEL sys
+CONFIG archiso_sys.cfg