| Message ID | 1438612891-3718-9-git-send-email-drjones@redhat.com |
|---|---|
| State | Superseded, archived |
| Headers | show |
On Mon, Aug 03, 2015 at 04:41:25PM +0200, Andrew Jones wrote: > Add the hvcall for putchar and use it in puts. That, along with a > couple more lines in start to prepare for C code, and a branch to > main(), gets us "hello world". Run with > > qemu-system-ppc64 -M pseries \ > -bios powerpc/boot_rom.bin \ > -display none -serial stdio \ > -kernel powerpc/selftest.elf > > (We're still not relocating yet, that comes in a later patch. Thus, > testing hello-world at this point requires a hacked QEMU and linking > the unit test at QEMU's kernel load address.) > > Signed-off-by: Andrew Jones <drjones@redhat.com> > --- > lib/powerpc/io.c | 15 +++++++++++++-- > powerpc/Makefile.common | 1 + > powerpc/cstart64.S | 27 +++++++++++++++++++++++++++ > 3 files changed, 41 insertions(+), 2 deletions(-) > > diff --git a/lib/powerpc/io.c b/lib/powerpc/io.c > index cf3b6347e1e46..a7eaafeca9205 100644 > --- a/lib/powerpc/io.c > +++ b/lib/powerpc/io.c > @@ -6,15 +6,26 @@ > * This work is licensed under the terms of the GNU LGPL, version 2. > */ > #include <libcflat.h> > +#include <asm/spinlock.h> > + > +extern void halt(int code); > +extern void putchar(int c); > + > +static struct spinlock uart_lock; > > void io_init(void) > { > } > > -void puts(const char *s __unused) > +void puts(const char *s) > { > + spin_lock(&uart_lock); > + while (*s) > + putchar(*s++); > + spin_unlock(&uart_lock); > } > > -void exit(int code __unused) > +void exit(int code) > { > + halt(code); > } > diff --git a/powerpc/Makefile.common b/powerpc/Makefile.common > index 5cd3ea8085038..d6356540918a5 100644 > --- a/powerpc/Makefile.common > +++ b/powerpc/Makefile.common > @@ -26,6 +26,7 @@ CFLAGS += -ffreestanding > CFLAGS += -Wextra > CFLAGS += -O2 > CFLAGS += -I lib -I lib/libfdt > +CFLAGS += -Wa,-mregnames > > asm-offsets = lib/$(ARCH)/asm-offsets.h > include scripts/asm-offsets.mak > diff --git a/powerpc/cstart64.S b/powerpc/cstart64.S > index d9b77f44f9e0e..d7c51cd352ee4 100644 > --- a/powerpc/cstart64.S > +++ b/powerpc/cstart64.S > @@ -6,14 +6,41 @@ > * This work is licensed under the terms of the GNU LGPL, version 2. > */ > > +#define HVSC .long 0x44000022 Unless your assembler is really old, you could probably use "sc 1" inline, instead of this macro. Not that it really matters. > +#define H_PUT_TERM_CHAR 0x58 > + > +#define LOAD_REG_IMMEDIATE(reg,expr) \ > + lis reg,(expr)@highest; \ > + ori reg,reg,(expr)@higher; \ > + rldicr reg,reg,32,31; \ > + oris reg,reg,(expr)@h; \ > + ori reg,reg,(expr)@l; > + > +#define LOAD_REG_ADDR(reg,name) \ > + ld reg,name@got(r2) > + > .section .init > > .globl start > start: > + LOAD_REG_IMMEDIATE(r1, stackptr) > + LOAD_REG_IMMEDIATE(r2, tocptr) > + bl .main > + bl .exit Is this built for ppc64 or ppc64le? IIUC under the new ABI version usually used on ppc64le, function descriptors are no longer used. And even under the old ABI, I think the assembler now has the smarts to avoid explicitly referencing the .-symbols. > b halt > > .text > +.align 3 > > .globl halt > halt: > 1: b 1b > + > +.globl putchar > +putchar: > + sldi r6, r3, 56 > + li r3, H_PUT_TERM_CHAR > + li r4, 0 /* vty-reg 0 means to use the default vty */ > + li r5, 1 /* sending just 1 byte */ > + HVSC > + blr
On Tue, Aug 04, 2015 at 01:50:39PM +1000, David Gibson wrote: > On Mon, Aug 03, 2015 at 04:41:25PM +0200, Andrew Jones wrote: > > Add the hvcall for putchar and use it in puts. That, along with a > > couple more lines in start to prepare for C code, and a branch to > > main(), gets us "hello world". Run with > > > > qemu-system-ppc64 -M pseries \ > > -bios powerpc/boot_rom.bin \ > > -display none -serial stdio \ > > -kernel powerpc/selftest.elf > > > > (We're still not relocating yet, that comes in a later patch. Thus, > > testing hello-world at this point requires a hacked QEMU and linking > > the unit test at QEMU's kernel load address.) > > > > Signed-off-by: Andrew Jones <drjones@redhat.com> > > --- > > lib/powerpc/io.c | 15 +++++++++++++-- > > powerpc/Makefile.common | 1 + > > powerpc/cstart64.S | 27 +++++++++++++++++++++++++++ > > 3 files changed, 41 insertions(+), 2 deletions(-) > > > > diff --git a/lib/powerpc/io.c b/lib/powerpc/io.c > > index cf3b6347e1e46..a7eaafeca9205 100644 > > --- a/lib/powerpc/io.c > > +++ b/lib/powerpc/io.c > > @@ -6,15 +6,26 @@ > > * This work is licensed under the terms of the GNU LGPL, version 2. > > */ > > #include <libcflat.h> > > +#include <asm/spinlock.h> > > + > > +extern void halt(int code); > > +extern void putchar(int c); > > + > > +static struct spinlock uart_lock; > > > > void io_init(void) > > { > > } > > > > -void puts(const char *s __unused) > > +void puts(const char *s) > > { > > + spin_lock(&uart_lock); > > + while (*s) > > + putchar(*s++); > > + spin_unlock(&uart_lock); > > } > > > > -void exit(int code __unused) > > +void exit(int code) > > { > > + halt(code); > > } > > diff --git a/powerpc/Makefile.common b/powerpc/Makefile.common > > index 5cd3ea8085038..d6356540918a5 100644 > > --- a/powerpc/Makefile.common > > +++ b/powerpc/Makefile.common > > @@ -26,6 +26,7 @@ CFLAGS += -ffreestanding > > CFLAGS += -Wextra > > CFLAGS += -O2 > > CFLAGS += -I lib -I lib/libfdt > > +CFLAGS += -Wa,-mregnames > > > > asm-offsets = lib/$(ARCH)/asm-offsets.h > > include scripts/asm-offsets.mak > > diff --git a/powerpc/cstart64.S b/powerpc/cstart64.S > > index d9b77f44f9e0e..d7c51cd352ee4 100644 > > --- a/powerpc/cstart64.S > > +++ b/powerpc/cstart64.S > > @@ -6,14 +6,41 @@ > > * This work is licensed under the terms of the GNU LGPL, version 2. > > */ > > > > +#define HVSC .long 0x44000022 > > Unless your assembler is really old, you could probably use "sc 1" > inline, instead of this macro. Not that it really matters. It makes sense to switch to sc for a new project. I'll do that. > > > +#define H_PUT_TERM_CHAR 0x58 > > + > > +#define LOAD_REG_IMMEDIATE(reg,expr) \ > > + lis reg,(expr)@highest; \ > > + ori reg,reg,(expr)@higher; \ > > + rldicr reg,reg,32,31; \ > > + oris reg,reg,(expr)@h; \ > > + ori reg,reg,(expr)@l; > > + > > +#define LOAD_REG_ADDR(reg,name) \ > > + ld reg,name@got(r2) > > + > > .section .init > > > > .globl start > > start: > > + LOAD_REG_IMMEDIATE(r1, stackptr) > > + LOAD_REG_IMMEDIATE(r2, tocptr) > > + bl .main > > + bl .exit > > Is this built for ppc64 or ppc64le? IIUC under the new ABI version > usually used on ppc64le, function descriptors are no longer used. And > even under the old ABI, I think the assembler now has the smarts to > avoid explicitly referencing the .-symbols. For now only building for ppc64, but eventually both. I'll remove the dots. Thanks, drew > > > b halt > > > > .text > > +.align 3 > > > > .globl halt > > halt: > > 1: b 1b > > + > > +.globl putchar > > +putchar: > > + sldi r6, r3, 56 > > + li r3, H_PUT_TERM_CHAR > > + li r4, 0 /* vty-reg 0 means to use the default vty */ > > + li r5, 1 /* sending just 1 byte */ > > + HVSC > > + blr > > -- > David Gibson | I'll have my music baroque, and my code > david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ > | _way_ _around_! > http://www.ozlabs.org/~dgibson -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/lib/powerpc/io.c b/lib/powerpc/io.c index cf3b6347e1e46..a7eaafeca9205 100644 --- a/lib/powerpc/io.c +++ b/lib/powerpc/io.c @@ -6,15 +6,26 @@ * This work is licensed under the terms of the GNU LGPL, version 2. */ #include <libcflat.h> +#include <asm/spinlock.h> + +extern void halt(int code); +extern void putchar(int c); + +static struct spinlock uart_lock; void io_init(void) { } -void puts(const char *s __unused) +void puts(const char *s) { + spin_lock(&uart_lock); + while (*s) + putchar(*s++); + spin_unlock(&uart_lock); } -void exit(int code __unused) +void exit(int code) { + halt(code); } diff --git a/powerpc/Makefile.common b/powerpc/Makefile.common index 5cd3ea8085038..d6356540918a5 100644 --- a/powerpc/Makefile.common +++ b/powerpc/Makefile.common @@ -26,6 +26,7 @@ CFLAGS += -ffreestanding CFLAGS += -Wextra CFLAGS += -O2 CFLAGS += -I lib -I lib/libfdt +CFLAGS += -Wa,-mregnames asm-offsets = lib/$(ARCH)/asm-offsets.h include scripts/asm-offsets.mak diff --git a/powerpc/cstart64.S b/powerpc/cstart64.S index d9b77f44f9e0e..d7c51cd352ee4 100644 --- a/powerpc/cstart64.S +++ b/powerpc/cstart64.S @@ -6,14 +6,41 @@ * This work is licensed under the terms of the GNU LGPL, version 2. */ +#define HVSC .long 0x44000022 +#define H_PUT_TERM_CHAR 0x58 + +#define LOAD_REG_IMMEDIATE(reg,expr) \ + lis reg,(expr)@highest; \ + ori reg,reg,(expr)@higher; \ + rldicr reg,reg,32,31; \ + oris reg,reg,(expr)@h; \ + ori reg,reg,(expr)@l; + +#define LOAD_REG_ADDR(reg,name) \ + ld reg,name@got(r2) + .section .init .globl start start: + LOAD_REG_IMMEDIATE(r1, stackptr) + LOAD_REG_IMMEDIATE(r2, tocptr) + bl .main + bl .exit b halt .text +.align 3 .globl halt halt: 1: b 1b + +.globl putchar +putchar: + sldi r6, r3, 56 + li r3, H_PUT_TERM_CHAR + li r4, 0 /* vty-reg 0 means to use the default vty */ + li r5, 1 /* sending just 1 byte */ + HVSC + blr
Add the hvcall for putchar and use it in puts. That, along with a couple more lines in start to prepare for C code, and a branch to main(), gets us "hello world". Run with qemu-system-ppc64 -M pseries \ -bios powerpc/boot_rom.bin \ -display none -serial stdio \ -kernel powerpc/selftest.elf (We're still not relocating yet, that comes in a later patch. Thus, testing hello-world at this point requires a hacked QEMU and linking the unit test at QEMU's kernel load address.) Signed-off-by: Andrew Jones <drjones@redhat.com> --- lib/powerpc/io.c | 15 +++++++++++++-- powerpc/Makefile.common | 1 + powerpc/cstart64.S | 27 +++++++++++++++++++++++++++ 3 files changed, 41 insertions(+), 2 deletions(-)