On 02/13/13 06:19, Kevin O'Connor wrote:
On Wed, Feb 13, 2013 at 04:52:09AM +0100, Laszlo Ersek wrote:
This series bears witness to my extreme cluelessness. With it I'm only asking if we can move the hypervisor/platform detection logic to SRCBOTH code, so that it sets up "PlatformRunningOn" for all of CSM, vgabios, and "normal" SeaBIOS.
It's possible to do this, but it's not a great way of detecting the platform - it can only detect Xen/KVM and not raw QEMU. On coreboot, it's possible to determine if qemu (or its derivatives) launched SeaBIOS by looking for the qemu signature in the vendor/part identifiers in the coreboot tables. David suggested that something similar could be done for CSM by looking at the SMBIOS tables.
The motivation is that running on qemu is now a requirement for logging to the qemu debug port, and logging to that port would be nice in all flavors & parts.
I recently pushed the "Improved multi-platform support" series, but I pulled out the CONFIG_DEBUG_IO change that allowed it to work with just CONFIG_QEMU_HARDWARE.
I think I understand. DEBUG_IO still depends on QEMU (from Gerd's commit 9600c800), and selecting CSM will not satisfy that.
I think it's possible to get it working with CONFIG_QEMU_HARDWARE with something like the patch below.
Are two builds necessary with this change? One with CSM && QEMU_HARDWARE (which will build a CSM-ized bios.bin that logs to the debug port, and a vgabios.bin that doesn't), and another with QEMU (implying QEMU_HARDWARE, from which build the bios.bin is to be ignored for CSM purposes, and the vgabios.bin is to be installed, because it logs to the debug port)?
Also, the current SeaVGABIOS code is checking for "!COREBOOT" in its Kconfig file - that should be changed to "QEMU". With that fixed this will be even less of a concern. (It really only makes sense to build a cirrus/bochs vgabios for QEMU - which would always have the debug port available.)
Yes, I think it would eliminate the non-debugport-logging vgabios.bin from the first (== CSM && QEMU_HARDWARE) build above.
... However, I think the (CSM && QEMU_HARDWARE) bios.bin would still not log to the debug port. The (GET_GLOBAL(PlatformRunningOn) & PF_QEMU) part would evaluate to false, for two reasons: first, qemu_ramsize_preinit() will not set the flag when !CONFIG_QEMU (which is implied by CONFIG_CSM); second, qemu_ramsize_preinit() is never even invoked in the CSM build.
Anyway I've been beating this dead horse long enough; I guess I can easily hack the DEBUG_IO dependency (and nothing else) in scratch builds.
Thanks for your help! Laszlo
-Kevin
diff --git a/Makefile b/Makefile index e02803e..b9fed0f 100644 --- a/Makefile +++ b/Makefile @@ -36,14 +36,14 @@ COMMONCFLAGS += $(call cc-option,$(CC),-nopie,) COMMONCFLAGS += $(call cc-option,$(CC),-fno-stack-protector,) COMMONCFLAGS += $(call cc-option,$(CC),-fno-stack-protector-all,)
-CFLAGS32FLAT := $(COMMONCFLAGS) -DMODE16=0 -DMODESEGMENT=0 -fomit-frame-pointer +CFLAGS32FLAT := $(COMMONCFLAGS) -DMODE16=0 -DMODESEGMENT=0 -fomit-frame-pointer -DMODEVGA=0 CFLAGSSEG := $(COMMONCFLAGS) -DMODESEGMENT=1 -fno-defer-pop \ $(call cc-option,$(CC),-fno-jump-tables,-DMANUAL_NO_JUMP_TABLE) \ $(call cc-option,$(CC),-fno-tree-switch-conversion,) -CFLAGS32SEG := $(CFLAGSSEG) -DMODE16=0 -fomit-frame-pointer +CFLAGS32SEG := $(CFLAGSSEG) -DMODE16=0 -fomit-frame-pointer -DMODEVGA=0 CFLAGS16INC := $(CFLAGSSEG) -DMODE16=1 -Wa,src/code16gcc.s \ $(call cc-option,$(CC),--param large-stack-frame=4,-fno-inline) -CFLAGS16 := $(CFLAGS16INC) -fomit-frame-pointer +CFLAGS16 := $(CFLAGS16INC) -fomit-frame-pointer -DMODEVGA=0
# Run with "make V=1" to see the actual compile commands ifdef V @@ -179,7 +179,7 @@ SRCVGA=src/output.c src/util.c src/pci.c \ vgasrc/stdvga.c vgasrc/stdvgamodes.c vgasrc/stdvgaio.c \ vgasrc/clext.c vgasrc/bochsvga.c vgasrc/geodevga.c
-CFLAGS16VGA = $(CFLAGS16INC) -Isrc +CFLAGS16VGA = $(CFLAGS16INC) -Isrc -DMODEVGA=1
$(OUT)vgaccode16.raw.s: $(OUT)autoconf.h ; $(call whole-compile, $(CFLAGS16VGA) -S, $(SRCVGA),$@)
diff --git a/src/Kconfig b/src/Kconfig index 4ddf9da..7df6c67 100644 --- a/src/Kconfig +++ b/src/Kconfig @@ -406,7 +406,7 @@ menu "Debugging" Base port for serial - generally 0x3f8, 0x2f8, 0x3e8, or 0x2e8.
config DEBUG_IO
depends on QEMU && DEBUG_LEVEL != 0
depends on QEMU_HARDWARE && DEBUG_LEVEL != 0 bool "Special IO port debugging" default y helpdiff --git a/src/output.c b/src/output.c index e623d37..27621f5 100644 --- a/src/output.c +++ b/src/output.c @@ -11,6 +11,7 @@ #include "bregs.h" // struct bregs #include "config.h" // CONFIG_* #include "biosvar.h" // GET_GLOBAL +#include "paravirt.h" // runningOnQEMU
struct putcinfo { void (*func)(struct putcinfo *info, char c); @@ -77,7 +78,7 @@ putc_debug(struct putcinfo *action, char c) { if (! CONFIG_DEBUG_LEVEL) return;
- if (CONFIG_DEBUG_IO)
- if (CONFIG_DEBUG_IO && runningOnQEMU()) // Send character to debug port. outb(c, GET_GLOBAL(DebugOutputPort)); if (c == '\n')
diff --git a/src/paravirt.h b/src/paravirt.h index 4438273..11343cd 100644 --- a/src/paravirt.h +++ b/src/paravirt.h @@ -14,7 +14,7 @@ extern int PlatformRunningOn;
static inline int runningOnQEMU(void) { return CONFIG_QEMU || (
CONFIG_QEMU_HARDWARE && GET_GLOBAL(PlatformRunningOn) & PF_QEMU);
!MODEVGA && CONFIG_QEMU_HARDWARE && GET_GLOBAL(PlatformRunningOn) & PF_QEMU);} static inline int runningOnXen(void) { return CONFIG_XEN && GET_GLOBAL(PlatformRunningOn) & PF_XEN;