SeaBIOS

seabios@seabios.org

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3799 discussions

How does call16 work from protected mode
by Himanshu Chauhan 07 Jun '22

07 Jun '22

Hi, I am trying to understand the call of 16-bit code from protected mode. I am tracing the code from "enable_vga_console" function. I see that it further calls "call16_int10". Further down somewhere (probably check_irqs), pause instruction is executed. I am trying to understand what is expected here. I assume pause is executed and SeaBIOS waits for an interrupt to arrive to finish the call16 processing. But I don't see RTC being programmed for interrupt. For which interrupt is SeaBIOS waiting? NMI? Regards Himanshu

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[PATCH 1/3] handle_1591: [INT15/AH=91h] Always set AH=0 and clear CF
by Lev Kujawski 02 Jun '22

02 Jun '22

References: R. Brown, "INT 15 - OS HOOK - DEVICE POST (AT,PS)", in The x86 Interrupt List. https://www.cs.cmu.edu/~ralf/files.html [Updated: 2018-02-28]. F. v. Gilluwe, The Undocumented PC. Boston, MA: Addison-Wesley, 1997, p. 780. Signed-off-by: Lev Kujawski <lkujaw(a)member.fsf.org> --- src/system.c | 1 + 1 file changed, 1 insertion(+) diff --git a/src/system.c b/src/system.c index 438e60e..ec99347 100644 --- a/src/system.c +++ b/src/system.c @@ -232,6 +232,7 @@ handle_1590(struct bregs *regs) static void handle_1591(struct bregs *regs) { + set_code_success(regs); } // keyboard intercept -- 2.34.1

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Open-Source Firmware Conference 2022
by Christian Walter 02 Jun '22

02 Jun '22

** *Dear SeaBIOS community,* * the OSFC is the biggest open-source firmware conference worldwide made by and for developers. After two years we can finally meet in person again. This year's OSFC will take place in Gothenburg, Sweden from September 19th - 21th. We will have a two day conference, followed by a one-day hackathon where we can hack together on hardware and firmware. Currently the Call for Participation is open, and I’d like to invite everyone in this community to submit talks and present new innovations, updates or problem talks. Additionally, you can already buy early bird tickets, so feel free to check out the homepage https://www.osfc.io <https://www.osfc.io>for more information. SeaBIOS and it's community has been a constant part of open-source firmware - and we'd love to see contributions from you on the OSFC 2022! If you have any questions feel free to drop me an email! Thank you! Chris * -- *Christian Walter* *Head of Firmware Development / Cyber Security * 9elements GmbH, Kortumstraße 19-21, 44787 Bochum, Germany Email: christian.walter(a)9elements.com Phone: _+49 234 68 94 188 <tel:+492346894188>_ Mobile: _+49 176 70845047 <tel:+4917670845047>_ Sitz der Gesellschaft: Bochum Handelsregister: Amtsgericht Bochum, HRB 17519 Geschäftsführung: Sebastian Deutsch, Eray Basar Datenschutzhinweise nach Art. 13 DSGVO <https://9elements.com/privacy>

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[PATCH v4 0/2] use large ZoneHigh when there is enough memory
by Gerd Hoffmann 03 May '22

03 May '22

v4: - make calculations more robust. v3: - check size instead of end address. Gerd Hoffmann (2): malloc: use variable for ZoneHigh size malloc: use large ZoneHigh when there is enough memory src/config.h | 3 ++- src/malloc.c | 23 ++++++++++++++--------- 2 files changed, 16 insertions(+), 10 deletions(-) -- 2.35.1

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EHCI cpage is out of range with qemu ehci controller
by lma 30 Apr '22

30 Apr '22

Hi all, I experienced an error about ehci current page on qemu + seabios v1.14: cpage out of range (5) processing error - resetting ehci HC We know that the EHCI spec defines valid range of ehci cpage to 0-4, But here is a 5, Obviously it's an issue. I added a EHCI controller, and attached a usb mass storage to the EHCI controller as boot device: host:~# qemu-system-x86_64 \ -accel kvm \ -bios /home/test/projects/seabios/out/bios.bin \ -m 4096 \ -device usb-ehci \ -blockdev driver=file,read-only=on,filename=/isos/openSUSE-Tumbleweed-GNOME-Live-x86_64-Snapshot20220314-Media.iso,node-name=iso \ -device usb-storage,drive=iso,bootindex=0 The issue is not 100% reproducible, I run the test 15 times with above steps, the issue occurs 1 or 2 times. The qemu version seems doesn't matter, I used to use qemu 5.2, 6.0 and latest git master, Got the same test result. It seems that the issue was introduced since seabios v1.14, It can be reproduced on latest seabios git master as well, It can't be reproduced on seabios 1.13 or older. The seabios commit b3fa8577 "kvm: add support for reading tsc frequency from kvmclock" seems to be the suspect. Thanks, Lin

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[PATCH v3 0/2] use large ZoneHigh when there is enough memory
by Gerd Hoffmann 28 Apr '22

28 Apr '22

v3: - check size instead of end address. Gerd Hoffmann (2): malloc: use variable for ZoneHigh size malloc: use large ZoneHigh when there is enough memory src/config.h | 3 ++- src/malloc.c | 18 +++++++++++------- 2 files changed, 13 insertions(+), 8 deletions(-) -- 2.35.1

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[PATCH v2 0/2] use large ZoneHigh when there is enough memory
by Gerd Hoffmann 26 Apr '22

26 Apr '22

Gerd Hoffmann (2): malloc: use variable for ZoneHigh size malloc: use large ZoneHigh when there is enough memory src/config.h | 3 ++- src/malloc.c | 18 +++++++++++------- 2 files changed, 13 insertions(+), 8 deletions(-) -- 2.35.1

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Re: Floppy setup
by Keith Hui 25 Apr '22

25 Apr '22

(Looping in the SeaBIOS mailing list again.) See this: https://www.seabios.org/Runtime_config It appears CMOS locations are a legacy artifact and files within the cbfs image (eg. etc/floppy0) is the preferred way of passing SeaBIOS settings. If you want a proper fix with the value stored in CMOS (and be configurable via nvramtool), you'll need to modify both SeaBIOS and the coreboot option table layout for your board. If you need help with coreboot and are not subscribed to that mailing list, I can reach out and loop you in. @Kevin - What are we to do for SeaBIOS settings that the we may want to change at runtime eg. via nvramtool? Are there any such settings? Keith On Sun, 24 Apr 2022 at 18:36, Petr Cvek <petrcvekcz(a)gmail.com> wrote: > > Linux actually reads the floppy type from the exact same CMOS location as QEMU compiled SeaBIOS: > > https://elixir.free-electrons.com/linux/v5.12.9/source/arch/x86/include/asm… > > and if I remember correctly I've had to force the type through floppy module parameter, before I modified the coreboot+SeaBIOS source codes. > > The other operating systems will probably try to read the CMOS location as well. IMO it is actually a standard bitfield in IBM PC compatible computer. Also all cmos.layout files start the configuration from bit 384 and some of them even have the first 120 bits explicitly defined as "reserved". > > Under these constraints I think it should be possible to change the line to something like this: > > if (CONFIG_QEMU || CONFIG_USE_CMOS) { > > With CONFIG_USE_CMOS be "n" by default so non floppy boards will end with the old code path. > > Petr > > > Dne 24. 04. 22 v 21:05 Keith Hui napsal(a): > > Hi Petr, > > > > Linux seems to have been able to pick up all the floppy drives on its own. > > > > But if you read a few more lines beyond the snippet you posted, you'll > > see that it only reads nvram for floppy types when compiled for and > > run on QEMU because that layout is hard coded and QEMU-specific. To > > extend it to other coreboot targets that layout will need to be > > incorporated into the option table of all coreboot mainboards, which > > isn't trivial and some boards don't even have floppy ports at all. And > > should those nvram bytes hold value for something else, results can be > > very unpredictable. > > > > You'll also see another way around it, using files etc/floppy0 and > > etc/floppy1 added to the coreboot image. Some tracing within this file > > will tell you what values to use. Downside is changing these values > > also requires reflashing. > > > > Hope this helps. > > > > Keith > > > > On Sun, 24 Apr 2022 at 07:15, Petr Cvek <petrcvekcz(a)gmail.com> wrote: > >> > >> Hello, > >> > >> I was playing with coreboot + floppy and it seems the drive type can be read from CMOS only if the machine is QEMU. > >> > >> payloads/external/SeaBIOS/seabios/src/hw/floppy.c > >> > >> floppy_setup(void) > >> { > >> ... > >> if (CONFIG_QEMU) { > >> u8 type = rtc_read(CMOS_FLOPPY_DRIVE_TYPE); > >> if (type & 0xf0) > >> addFloppy(0, type >> 4); > >> ... > >> } else { > >> u8 type = romfile_loadint("etc/floppy0", 0); > >> ... > >> > >> Is it possible enable this function for a real coreboot target? What way is the most acceptable way to do it (something like || CONFIG_USE_CMOS)? > >> > >> I've forced it with "always true" condition and after adding configurations to cmos table and superio in coreboot, I was able to boot msdos on kontron 986lcd-m board. > >> > >> P.S. original message got stuck somewhere in the mailserver as I forgot to subscribe to seabios mailing list. > >> > >> Regards, > >> Petr > >> _______________________________________________ > >> SeaBIOS mailing list -- seabios(a)seabios.org > >> To unsubscribe send an email to seabios-leave(a)seabios.org

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Floppy setup
by Petr Cvek 24 Apr '22

24 Apr '22

Hello, I was playing with coreboot + floppy and it seems the drive type can be read from CMOS only if the machine is QEMU. payloads/external/SeaBIOS/seabios/src/hw/floppy.c floppy_setup(void) { ... if (CONFIG_QEMU) { u8 type = rtc_read(CMOS_FLOPPY_DRIVE_TYPE); if (type & 0xf0) addFloppy(0, type >> 4); ... } else { u8 type = romfile_loadint("etc/floppy0", 0); ... Is it possible enable this function for a real coreboot target? What way is the most acceptable way to do it (something like || CONFIG_USE_CMOS)? I've forced it with "always true" condition and after adding configurations to cmos table and superio in coreboot, I was able to boot msdos on kontron 986lcd-m board. P.S. original message got stuck somewhere in the mailserver as I forgot to subscribe to seabios mailing list. Regards, Petr

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CDROM/DVD timeouts on real hardware
by Petr Cvek 24 Apr '22

24 Apr '22

Hi, Has anybody tried to boot from CDROM/DVD non-QEMU seabios lately? I've tried to boot a few CDs/DVDs on AHCI and IDE drives and although the drive is detected, it will fail to boot. There is a timeout after which the next drive will boot. It seems the timeout is located somewhere in payloads/external/SeaBIOS/seabios/src/cdrom.c in function cdrom_boot(). When I tried to comment out this test: int ret = scsi_is_ready(&dop); if (ret) dprintf(5, "scsi_is_ready returned %d\n", ret); I was able to boot windows 98SE installation CD, but it failed after a few sectors (probably when the readiness was needed to be tested :D). If somebody can confirm it is not just my board setup (kontron 986lcd-m with the current coreboot branch) I would be grateful. P.S. original message got stuck somewhere in the mailserver as I forgot to subscribe to seabios mailing list. regards, Petr

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