March 2025 - SeaBIOS - mail.coreboot.org

regression: cannot boot from nvme anymore, disabling 64bit pci io window helps
by Marek Marczykowski-Górecki July 7, 2026

July 7, 2026

Hi, After an update some time ago, a VM wit 8GB RAM cannot boot from nvme anymore. QEMU cmdline: /usr/bin/qemu-system-x86_64 \ -chardev ringbuf,id=serial0,logfile=serial0,logappend=on \ -serial chardev:serial0 \ -m 8192 \ -enable-kvm \ -vnc :2,share=force-shared \ -blockdev driver=file,node-name=hd0-file,filename=disk.qcow2,cache.no-flush=on,discard=unmap \ -blockdev driver=qcow2,node-name=hd0,file=hd0-file,cache.no-flush=on,discard=unmap \ -device nvme,id=hd0-device,drive=hd0,serial=hd0 \ -chardev stdio,id=seabios -device isa-debugcon,iobase=0x402,chardev=seabios \ -bios /home/user/seabios/out/bios.bin There is nothing fancy on the disk, just standard grub2 setup, but also I believe it doesn't matter, as it doesn't even reach grub. When it fails, the seabios log contains: PCI: 64: 0000038000000000 - 0000038040000000 PCI: map device bdf=00:04.0 bar 0, addr 38000000000, size 00004000 [mem] ... Searching bootorder for: /pci@i0cf8/isa@1/fdc@03f0/floppy@0 ATA controller 1 at 1f0/3f4/0 (irq 14 dev 9) ATA controller 2 at 170/374/0 (irq 15 dev 9) Searching bootorder for: HALT Can not map memory bar over 4Gig ... Boot failed: could not read the boot disk Working version has this instead: PCI: map device bdf=00:04.0 bar 0, addr febf0000, size 00004000 [mem] ... Booting from Hard Disk... Booting from 0000:7c00 00:04.0 is the nvme. I'm attaching full logs for both cases. Bisect shows: 96a8d130a8c2e908e357ce62cd713f2cc0b0a2eb is the first bad commit commit 96a8d130a8c2e908e357ce62cd713f2cc0b0a2eb (HEAD) Author: Gerd Hoffmann <kraxel(a)redhat.com> Date: Fri Sep 9 10:17:15 2022 +0200 be less conservative with the 64bit pci io window Current seabios code will only enable and use the 64bit pci io window in case it runs out of space in the 32bit pci mmio window below 4G. This patch will also enable the 64bit pci io window when (a) RAM above 4G is present, and (b) the physical address space size is known, and (c) seabios is running on a 64bit capable processor. This operates with the assumption that guests which are ok with memory above 4G most likely can handle mmio above 4G too. In case the 64bit pci io window is enabled also assign more memory to prefetchable pci bridge windows and the complete 64bit pci io window. The total mmio window size is 1/8 of the physical address space. Minimum bridge windows size is 1/256 of the total mmio window size. Signed-off-by: Gerd Hoffmann <kraxel(a)redhat.com> I've tried the recent "[PATCH] limit address space used for pci devices, part two" patch from the ML, but it doesn't help. OTOH, the series with "only enable 64bit pci io window when RAM >64G" does help. -- Best Regards, Marek Marczykowski-Górecki Invisible Things Lab

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[PATCH v2 0/2] add guest hint for memory layout, take three
by Gerd Hoffmann June 3, 2025

June 3, 2025

Gerd Hoffmann (2): add romfile_loadbool() update pci_pad_mem64 handling src/romfile.h | 1 + src/fw/pciinit.c | 13 ++++++++++--- src/romfile.c | 23 +++++++++++++++++++++++ 3 files changed, 34 insertions(+), 3 deletions(-) -- 2.47.0

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[PATCH] kconfig: fix the check-lxdialog.sh to work with gcc 14+
by nikolar March 10, 2025

March 10, 2025

--- scripts/kconfig/lxdialog/check-lxdialog.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/scripts/kconfig/lxdialog/check-lxdialog.sh b/scripts/kconfig/lxdialog/check-lxdialog.sh index 9d2a4c58..66bfcb54 100644 --- a/scripts/kconfig/lxdialog/check-lxdialog.sh +++ b/scripts/kconfig/lxdialog/check-lxdialog.sh @@ -43,7 +43,7 @@ trap "rm -f $tmp" 0 1 2 3 15 check() { $cc -x c - -o $tmp 2>/dev/null <<'EOF' #include CURSES_LOC -main() {} +int main() {} EOF if [ $? != 0 ]; then echo " *** Unable to find the ncurses libraries or the" 1>&2 -- 2.48.1

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[PATCH] Fix AHCI Disk Detection when using EDK2 CSM
by Christopher Lentocha March 10, 2025

March 10, 2025

For whatever reason, when you compile SeaBIOS in Csm16 mode, and use it under EDK2's OvmfPkg, the ATA_CMD_IDENTIFY_PACKET_DEVICE command doesn't work properly, therefore, SeaBIOS detects the "SATA HARDDISK" as a "SATA CDROM" device, in QEMU. Despite the Tianocore developers seem to have removed support for Csm16 some time ago, if we decide to remove Csm16 mode in SeaBIOS in favor of that, at least we have the last commit of Csm16 working properly and not half-broken. In order to fix this bug, I decided to add another command, that command being ATA_CMD_DEVICE_RESET, right before the ATA_CMD_IDENTIFY_PACKET_DEVICE command is called. Signed-off-by: Christopher Lentocha <christopherericlentocha(a)gmail.com> --- src/hw/ahci.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/src/hw/ahci.c b/src/hw/ahci.c index 4f0f640..e0864fa 100644 --- a/src/hw/ahci.c +++ b/src/hw/ahci.c @@ -484,7 +484,8 @@ static int ahci_port_setup(struct ahci_port_s *port) /* start device */ cmd |= PORT_CMD_START; ahci_port_writel(ctrl, pnr, PORT_CMD, cmd); - + sata_prep_simple(&port->cmd->fis, ATA_CMD_DEVICE_RESET); + ahci_command(port, 0, 0, buffer, sizeof(buffer)); sata_prep_simple(&port->cmd->fis, ATA_CMD_IDENTIFY_PACKET_DEVICE); rc = ahci_command(port, 0, 0, buffer, sizeof(buffer)); if (rc == 0) { -- 2.38.1

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