The DX-3000 does not have a conventional BIOS. It uses the open source
SeaBIOS that is used in conjunction with coreboot. On boot it briefly
shows: SeaBIOS (Epic 5 1.00).
I have found no way to interrupt the boot process and bring up some form of boot menu. The only way I have been able to boot from USB is by removing the Micro SD card.
At the moment, as far as I can see, to install a new OS requires the Micro SD card or mSATA drive to be prepared on another system.
I haven't yet got up the energy to get to grips with Coreboot/SeaBIOS to see if anything can be sorted on that front.
The 'bios' flash chip can be read by flashrom. Running ""strings" on an image of the BIOS chip does produce the build config of what is there:
CONFIG_LOCALVERSION="QSR Automations Epic 5" CONFIG_CBFS_PREFIX="fallback" CONFIG_COMPILER_GCC=y CONFIG_COMPRESS_RAMSTAGE=y CONFIG_INCLUDE_CONFIG_FILE=y CONFIG_VENDOR_QSR=y CONFIG_BOARD_SPECIFIC_OPTIONS=y CONFIG_MAINBOARD_DIR="qsr/epic5" CONFIG_MAINBOARD_PART_NUMBER="Epic 5" CONFIG_IRQ_SLOT_COUNT=11 CONFIG_MAINBOARD_VENDOR="QSR" CONFIG_APIC_ID_OFFSET=0x0 CONFIG_HW_MEM_HOLE_SIZEK=0x200000 CONFIG_MAX_CPUS=1 CONFIG_MAX_PHYSICAL_CPUS=1 CONFIG_MEM_TRAIN_SEQ=2 CONFIG_RAMTOP=0x1000000 CONFIG_HEAP_SIZE=0xc0000 CONFIG_RAMBASE=0x200000 CONFIG_VGA_BIOS_ID="1002,9802" CONFIG_STACK_SIZE=0x10000 CONFIG_ACPI_SSDTX_NUM=0 CONFIG_SIO_PORT=0x4e CONFIG_ONBOARD_VGA_IS_PRIMARY=y CONFIG_PCI_ROM_RUN=y CONFIG_UDELAY_IO=y CONFIG_DCACHE_RAM_GLOBAL_VAR_SIZE=0x0 CONFIG_SERIAL_CPU_INIT=y CONFIG_AMD_AGESA=y CONFIG_MMCONF_BASE_ADDRESS=0xf8000000 CONFIG_BOOTBLOCK_SOUTHBRIDGE_INIT="southbridge/amd/cimx/sb800/bootblock.c" CONFIG_GENERATE_PIRQ_TABLE=y CONFIG_LOGICAL_CPUS=y CONFIG_IOAPIC=y CONFIG_TTYS0_BAUD=115200 CONFIG_TTYS0_BASE=0x3f8 CONFIG_TTYS0_LCS=3 CONFIG_DEFAULT_CONSOLE_LOGLEVEL=0 CONFIG_MAXIMUM_CONSOLE_LOGLEVEL=0 CONFIG_CONSOLE_SERIAL8250=y CONFIG_VAR_MTRR_HOLE=y CONFIG_LIFT_BSP_APIC_ID=y CONFIG_BOARD_QSR_EPIC5=y CONFIG_BOARD_ROMSIZE_KB_4096=y CONFIG_COREBOOT_ROMSIZE_KB_2048=y CONFIG_COREBOOT_ROMSIZE_KB=2048 CONFIG_ROM_SIZE=0x200000 CONFIG_ARCH_X86=y CONFIG_ROMBASE=0xffff0000 CONFIG_MAX_REBOOT_CNT=3 CONFIG_X86_BOOTBLOCK_SIMPLE=y CONFIG_BOOTBLOCK_SOURCE="bootblock_simple.c" CONFIG_PC80_SYSTEM=y CONFIG_BOOTBLOCK_NORTHBRIDGE_INIT="northbridge/amd/agesa/family14/bootblock.c" CONFIG_LITTLE_ENDIAN=y CONFIG_CPU_ADDR_BITS=36 CONFIG_CPU_SOCKET_TYPE=0x10 CONFIG_CBB=0x0 CONFIG_CDB=0x18 CONFIG_XIP_ROM_SIZE=0x100000 CONFIG_DIMM_SUPPORT=0x0104 CONFIG_XIP_ROM_BASE=0xfff00000 CONFIG_HAVE_INIT_TIMER=y CONFIG_CPU_AMD_AGESA_FAMILY14=y CONFIG_CACHE_AS_RAM=y CONFIG_SB_HT_CHAIN_UNITID_OFFSET_ONLY=y CONFIG_VIDEO_MB=0 CONFIG_AMDMCT=y CONFIG_MMCONF_BUS_NUMBER=16 CONFIG_NORTHBRIDGE_AMD_AGESA_FAMILY14=y CONFIG_NORTHBRIDGE_INTEL_I5000_RAM_CHECK=y CONFIG_AMD_SB_CIMX=y CONFIG_SOUTHBRIDGE_AMD_CIMX_SB800=y CONFIG_IDE_COMBINED_MODE=0x1 CONFIG_SB800_SATA_AHCI=y CONFIG_SB800_SATA_MODE=0x2 CONFIG_AHCI_ROM_ID="1002,4390" CONFIG_SUPERIO_FINTEK_F81865F=y CONFIG_VGA_BRIDGE_SETUP=y CONFIG_VGA_ROM_RUN=y CONFIG_PCI_OPTION_ROM_RUN_REALMODE=y CONFIG_PCIX_PLUGIN_SUPPORT=y CONFIG_PCIEXP_PLUGIN_SUPPORT=y CONFIG_AGP_PLUGIN_SUPPORT=y CONFIG_CARDBUS_PLUGIN_SUPPORT=y CONFIG_PCI_BUS_SEGN_BITS=0 CONFIG_MMCONF_SUPPORT=y CONFIG_CONSOLE_SERIAL_COM1=y CONFIG_CONSOLE_SERIAL_115200=y CONFIG_MAXIMUM_CONSOLE_LOGLEVEL_0=y CONFIG_DEFAULT_CONSOLE_LOGLEVEL_0=y CONFIG_POST_PORT=0x80 CONFIG_HAVE_UART_IO_MAPPED=y CONFIG_HAVE_HARD_RESET=y CONFIG_HAVE_MAINBOARD_RESOURCES=y CONFIG_HAVE_OPTION_TABLE=y CONFIG_PCI_IO_CFG_EXT=y CONFIG_GFXUMA=y CONFIG_HAVE_ACPI_TABLES=y CONFIG_HAVE_MP_TABLE=y CONFIG_HAVE_PIRQ_TABLE=y CONFIG_GENERATE_ACPI_TABLES=y CONFIG_GENERATE_MP_TABLE=y CONFIG_GENERATE_SMBIOS_TABLES=y CONFIG_WRITE_HIGH_TABLES=y CONFIG_MULTIBOOT=y CONFIG_PAYLOAD_ELF=y CONFIG_PAYLOAD_FILE="../seabios/out/bios.bin.elf" CONFIG_COMPRESSED_PAYLOAD_LZMA=y CONFIG_GDB_STUB=y CONFIG_BOARD_HAS_FADT=y CONFIG_HAVE_BUS_CONFIG=y CONFIG_ID_SECTION_OFFSET=0x80