SeaBIOS November 2018

seabios@seabios.org

15 participants
38 discussions

Re: [SeaBIOS] [PATCH] ramdisk: search for all available floppy images instead of one
by Kevin O'Connor 16 Nov '18

16 Nov '18

On Sun, Nov 11, 2018 at 02:12:09AM +0300, Mike Banon wrote: > > However I'm concerned that this would reserve memory for all > > of the floppy images in the e820 map (and thus the final OS > > would not be able to use that memory). > > sorry Kevin I'm not fully understanding the consequences. Would > reserving e820 memory for all the floppies - result in a slightly > lower amount of available RAM to OS (e.g. just 14 MB lower if I add 10 > floppies) or there could be more serious problems? Just the loss of 14MB of ram. It seems odd to reserve that ram when I expect one would rarely use it. Arguably, seabios shouldn't reserve even 1.4MB of ram if one isn't actually booting from the given image, but extending this to every image found when most wouldn't even be accessible seems even worse. >When I've been > testing this patch - together with "35 boot menu entries" patch by > Ivan - https://mail.coreboot.org/pipermail/seabios/2017-June/011416.html > - I added about 30 floppies and everything seemed to work perfectly. > If there are no other possible problems, I am okay with slightly lower > amount of RAM - and only the "multiple floppies" users will be > affected. Also, what's good about this patch is that its' only a small > change for SeaBIOS source code - mostly placing the "floppy searching" > code inside the "for" cycle. But I could try to do something with the > allocation part if that wouldn't turn out too difficult Okay, thanks. We're planning to make a SeaBIOS release in a few days and this change would be post release anyway. -Kevin

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Re: [SeaBIOS] [Qemu-devel] SeaBIOS booting time optimization
by Stefan Hajnoczi 16 Nov '18

16 Nov '18

On Fri, Nov 16, 2018 at 4:21 PM Stefano Garzarella <sgarzare(a)redhat.com> wrote: > I'm investigating the SeaBIOS booting time, to understand if we can reduce > the boot time in some cases (e.g. legacy hardware is not needed). I think > this > can be interesting also for NEMU developers. Questions for NEMU folks: qboot isn't part of the virt-x86 NEMU tree and is only mentioned in one or two places. Is NEMU focussing exclusively on OVMF guest firmware instead of qboot? Are there other boot time optimizations in NEMU that are a candidate for upstreaming? Stefan

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SeaBIOS booting time optimization
by Stefano Garzarella 16 Nov '18

16 Nov '18

Hi, I'm investigating the SeaBIOS booting time, to understand if we can reduce the boot time in some cases (e.g. legacy hardware is not needed). I think this can be interesting also for NEMU developers. Following this thread ( https://mail.coreboot.org/pipermail/seabios/2015-July/009497.html), I'm using qboot (https://github.com/bonzini/qboot) to compare the SeaBIOS booting time. As Paolo did in qboot, I manually add small debug port writes in SeaBIOS and linuxboot_dma.c (QEMU) to trace the events with perf (kvm_pio events) The goal is to have only one image of SeaBIOS configurable at runtime to reduce the boot time, avoiding unnecessary initialization. Any pointers or suggestions would be helpful. Following I put some preliminary measurements that I obtained: I used this QEMU command line: ./qemu-system-x86_64 -bios $BIOS -m 1G -cpu host -M accel=kvm \ -kernel /boot/vmlinuz-4.18.18-300.fc29.x86_64 -append 'console=ttyS0' \ -nographic -serial mon:stdio For each test, I measured these times (in milliseconds) relative to the "sched_process_exec" event: - qemu_init_end: first kvm_entry (i.e. QEMU initialized has finished) - fw_start: first entry of the BIOS - fw_do_boot: after the BIOS initialization (e.g. PCI setup, etc.) - linux_start_boot: before the jump to the Linux kernel # qboot BIOS=/home/stefano/repos/qboot/bios.bin qemu_init_end: 40.561234 fw_start: 40.721729 (+0.160495) fw_do_boot: 47.025591 (+6.303862) linux_start_boot: 48.874112 (+1.848521) # SeaBIOS with default configuration BIOS=/home/stefano/repos/seabios/out_default/bios.bin qemu_init_end: 40.419451 fw_start: 40.639967 (+0.220516) fw_do_boot: 886.668828 (+846.028861) linux_start_boot: 889.723547 (+3.054719) # SeaBIOS with Kevin's configuration # (https://mail.coreboot.org/pipermail/seabios/2015-July/009508.html) # Note: this SeaBIOS setup is so stripped down that it can't actually boot an OS BIOS=/home/stefano/repos/seabios/out_kevin/bios.bin qemu_init_end: 40.676412 fw_start: 40.755757 (+0.079345) fw_do_boot: 56.427023 (+15.671266) I did the same tests also with NEMU (without using -M virt) and I have approximately the same results. As the next step, I'll start from Kevin's configuration to have a minimal SeaBIOS image ables to boot a Linux kernel. Thanks, Stefano -- Stefano Garzarella Red Hat

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Re: [SeaBIOS] [PATCH] ramdisk: search for all available floppy images instead of one
by Kevin O'Connor 10 Nov '18

10 Nov '18

On Fri, Nov 02, 2018 at 01:07:20AM +0300, Mike Banon wrote: > All the floppy images available at CBFS will be found and listed in a > boot menu, instead of the first found. Could be highly valuable if you > are participating in a hobby OS development - would like to test > multiple versions of your floppy in the same coreboot image, to reduce > the amount of re-flashes and accelerate the development at bare metal > - or simply would like to access multiple floppies as a coreboot user; > for example: KolibriOS (nice assembly OS with GUI), FreeDOS, Visopsys > and memtest (coreboot's own memtest version is a bit buggy, e.g. > external USB keyboard isn't working there at some laptops) Thanks. However I'm concerned that this would reserve memory for all of the floppy images in the e820 map (and thus the final OS would not be able to use that memory). I think if multiple floppy support was desired then we'd want to delay memory reservation until after a particular image was selected in the boot menu. -Kevin

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[PATCH] coreboot: update memory table before handling execution to payload/system
by Krystian Hebel 10 Nov '18

10 Nov '18

SeaBIOS modifies its internal e820 structure, but does not propagate these changes back to coreboot tables. This resulted in multiple errors in MemTest86 when run on 2 GB platforms, probably because of some memory-mapped devices. This patch copies back modified e820 tables before booting an OS or a payload. Change-Id: I16a3f059695717daedb1e997ce4e62018c7e02b3 Signed-off-by: Krystian Hebel <krystian.hebel(a)3mdeb.com> --- src/e820map.c | 2 ++ src/e820map.h | 2 ++ src/fw/coreboot.c | 50 +++++++++++++++++++++++++++++++++++++++++++---- 3 files changed, 50 insertions(+), 4 deletions(-) diff --git a/src/e820map.c b/src/e820map.c index 39445cf6399d..2d2de6094b14 100644 --- a/src/e820map.c +++ b/src/e820map.c @@ -148,5 +148,7 @@ e820_remove(u64 start, u64 size) void e820_prepboot(void) { + // Synchronize memory maps. + coreboot_update_memtable(); dump_map(); } diff --git a/src/e820map.h b/src/e820map.h index de8b523003c5..78bf1ce76572 100644 --- a/src/e820map.h +++ b/src/e820map.h @@ -23,4 +23,6 @@ void e820_prepboot(void); extern struct e820entry e820_list[]; extern int e820_count; +extern void coreboot_update_memtable(void); + #endif // e820map.h diff --git a/src/fw/coreboot.c b/src/fw/coreboot.c index 7c0954b5398c..aa07baad3a7f 100644 --- a/src/fw/coreboot.c +++ b/src/fw/coreboot.c @@ -189,10 +189,6 @@ coreboot_preinit(void) e820_add(m->start, m->size, type); } - // Ughh - coreboot likes to set a map at 0x0000-0x1000, but this - // confuses grub. So, override it. - e820_add(0, 16*1024, E820_RAM); - struct cb_cbmem_ref *cbref = find_cb_subtable(cbh, CB_TAG_CBMEM_CONSOLE); if (cbref) { cbcon = (void*)(u32)cbref->cbmem_addr; @@ -567,3 +563,49 @@ cbfs_payload_setup(void) boot_add_cbfs(cfile->fhdr, desc, bootprio_find_named_rom(filename, 0)); } } + +// Mirror changes done on e820 to coreboot tables. +void +coreboot_update_memtable(void) +{ + if (!CONFIG_COREBOOT) + return; + + // Find coreboot table. + struct cb_header *cbh = find_cb_table(); + if (!cbh) { + dprintf(1, "Unable to find coreboot table!\n"); + return; + } + char *end = (char *)cbh + sizeof(*cbh) + cbh->table_bytes; + dprintf(3, "Now attempting to find coreboot memory map\n"); + struct cb_memory *dst = find_cb_subtable(cbh, CB_TAG_MEMORY); + if (!dst) { + dprintf(1, "Unable to find coreboot memory table!\n"); + return; + } + + // Remove old memory table, overwriting it with following subtables + // and append an updated memory table to the end. + u32 old_size = dst->size; + char *src = (char *)dst + old_size; + memcpy(dst, src, (end - src)); + dst = (struct cb_memory *)(end - old_size); + u32 new_size = e820_count * sizeof(struct e820entry); + dst->tag = CB_TAG_MEMORY; + // Tables are binary compatible, except that CB_MEM_TABLE became + // E820_RESERVED. + memcpy((char*)dst + sizeof(struct cb_memory), e820_list, new_size); + new_size += sizeof(struct cb_memory); + dst->size = new_size; + + // Update header fields (size and checksum). + cbh->table_bytes += new_size - old_size; + cbh->table_checksum = ipchksum((char*)cbh + sizeof(*cbh), cbh->table_bytes); + cbh->header_checksum = 0; + cbh->header_checksum = ipchksum((char*)cbh, sizeof(*cbh)); + + // Ughh - coreboot likes to set a map at 0x0000-0x1000, but this + // confuses grub. So, override it in e820 only. + e820_add(0, 16*1024, E820_RAM); +} -- 2.17.1

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[PATCH] shadow: Rework bios copy code to prevent gcc array-bounds warning
by Kevin O'Connor 10 Nov '18

10 Nov '18

Signed-off-by: Kevin O'Connor <kevin(a)koconnor.net> --- src/fw/shadow.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/src/fw/shadow.c b/src/fw/shadow.c index 987eaf4..4c627a8 100644 --- a/src/fw/shadow.c +++ b/src/fw/shadow.c @@ -173,9 +173,9 @@ qemu_reboot(void) return; // QEMU doesn't map 0xc0000-0xfffff back to the original rom on a // reset, so do that manually before invoking a hard reset. - void *cstart = VSYMBOL(code32flat_start), *cend = VSYMBOL(code32flat_end); - void *hrp = &HaveRunPost; - if (readl(hrp + BIOS_SRC_OFFSET)) { + void *flash = (void*)BIOS_SRC_OFFSET; + u32 hrp = (u32)&HaveRunPost; + if (readl(flash + hrp)) { // There isn't a pristine copy of the BIOS at 0xffff0000 to copy if (HaveRunPost == 3) { // In a reboot loop. Try to shutdown the machine instead. @@ -187,8 +187,9 @@ qemu_reboot(void) } else { // Copy the BIOS making sure to only reset HaveRunPost at end make_bios_writable(); - memcpy(cstart, cstart + BIOS_SRC_OFFSET, hrp - cstart); - memcpy(hrp + 4, hrp + 4 + BIOS_SRC_OFFSET, cend - (hrp + 4)); + u32 cstart = SYMBOL(code32flat_start), cend = SYMBOL(code32flat_end); + memcpy((void*)cstart, flash + cstart, hrp - cstart); + memcpy((void*)hrp + 4, flash + hrp + 4, cend - (hrp + 4)); barrier(); HaveRunPost = 0; barrier(); -- 2.17.2

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[PATCH] pvscsi: Scan all 64 possible targets
by Shmuel Eiderman 10 Nov '18

10 Nov '18

The max number of targets per PVSCSI controller is 64, not 7. This can easily be seen in QEMU PVSCSI emulation code (hw/scsi/vmw_pvscsi.c) as PVSCSI_MAX_DEVS, which defines the number of targets, have value of 64. Fixes: 83d60b3c474b ("Add pvscsi boot support") Reviewed-by: Liran Alon <liran.alon(a)oracle.com> Reviewed-by: Mark Kanda <mark.kanda(a)oracle.com> Signed-off-by: Shmuel Eiderman <shmuel.eiderman(a)oracle.com> --- src/hw/pvscsi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/hw/pvscsi.c b/src/hw/pvscsi.c index d62d0a0..e0ea33c 100644 --- a/src/hw/pvscsi.c +++ b/src/hw/pvscsi.c @@ -310,7 +310,7 @@ init_pvscsi(void *data) struct pvscsi_ring_dsc_s *ring_dsc = NULL; pvscsi_init_rings(iobase, &ring_dsc); int i; - for (i = 0; i < 7; i++) + for (i = 0; i < 64; i++) pvscsi_scan_target(pci, iobase, ring_dsc, i); } -- 2.16.1

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[PATCH] ramdisk: search for all available floppy images instead of one
by Mike Banon 01 Nov '18

01 Nov '18

All the floppy images available at CBFS will be found and listed in a boot menu, instead of the first found. Could be highly valuable if you are participating in a hobby OS development - would like to test multiple versions of your floppy in the same coreboot image, to reduce the amount of re-flashes and accelerate the development at bare metal - or simply would like to access multiple floppies as a coreboot user; for example: KolibriOS (nice assembly OS with GUI), FreeDOS, Visopsys and memtest (coreboot's own memtest version is a bit buggy, e.g. external USB keyboard isn't working there at some laptops) Shortened patch description message: All the available floppy images will be found and listed in a boot menu, instead of the first found. Useful if you are participating in a hobby OS development or would like to access multiple floppies as a coreboot user. Signed-off-by: Mike Banon <mikebdp2(a)gmail.com> --- diff --git a/src/hw/ramdisk.c b/src/hw/ramdisk.c index b9e9baa..0cd8470 100644 --- a/src/hw/ramdisk.c +++ b/src/hw/ramdisk.c @@ -23,40 +23,51 @@ ramdisk_setup(void) if (!CONFIG_FLASH_FLOPPY) return; + struct romfile_s *file = NULL; + char *filename, *desc; + u32 size; + int ftype, ret; + void *pos; + struct drive_s *drive; + + for (;;) { + - // Find image. - struct romfile_s *file = romfile_findprefix("floppyimg/", NULL); - if (!file) - return; + // Find the next image. + file = romfile_findprefix("floppyimg/", file); + if (!file) + return; - const char *filename = file->name; - u32 size = file->size; - dprintf(3, "Found floppy file %s of size %d\n", filename, size); - int ftype = find_floppy_type(size); - if (ftype < 0) { - dprintf(3, "No floppy type found for ramdisk size\n"); - return; - } + filename = file->name; + size = file->size; + dprintf(3, "Found floppy file %s of size %d\n", filename, size); + ftype = find_floppy_type(size); + if (ftype < 0) { + dprintf(3, "No floppy type found for ramdisk size\n"); + return; + } - // Allocate ram for image. - void *pos = memalign_tmphigh(PAGE_SIZE, size); - if (!pos) { - warn_noalloc(); - return; - } - e820_add((u32)pos, size, E820_RESERVED); + // Allocate ram for image. + pos = memalign_tmphigh(PAGE_SIZE, size); + if (!pos) { + warn_noalloc(); + return; + } + e820_add((u32)pos, size, E820_RESERVED); - // Copy image into ram. - int ret = file->copy(file, pos, size); - if (ret < 0) - return; + // Copy image into ram. + ret = file->copy(file, pos, size); + if (ret < 0) + return; - // Setup driver. - struct drive_s *drive = init_floppy((u32)pos, ftype); - if (!drive) - return; + // Setup driver. + drive = init_floppy((u32)pos, ftype); + if (!drive) + return; - drive->type = DTYPE_RAMDISK; - dprintf(1, "Mapping floppy %s to addr %p\n", filename, pos); - char *desc = znprintf(MAXDESCSIZE, "Ramdisk [%s]", &filename[10]); - boot_add_floppy(drive, desc, bootprio_find_named_rom(filename, 0)); + drive->type = DTYPE_RAMDISK; + dprintf(1, "Mapping floppy %s to addr %p\n", filename, pos); + desc = znprintf(MAXDESCSIZE, "Ramdisk [%s]", &filename[10]); + boot_add_floppy(drive, desc, bootprio_find_named_rom(filename, 0)); + + } } static int

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SeaBIOS November 2018