xen/arch/arm/arm64/debug-meson.inc | 55 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) create mode 100644 xen/arch/arm/arm64/debug-meson.inc
This patch adds earlyprintk support for Amlogic Meson SoC based
boards.
ATF[1] and U-boot[2] already initialize the UART for us. So no need to do it again.
Tested With:
http://wiki.friendlyarm.com/wiki/index.php/NanoPi_K2
[1]: https://github.com/ARM-software/arm-trusted-firmware/blob/master/drivers/meson/console/aarch64/meson_console.S#L92
[2]: https://github.com/u-boot/u-boot/blob/master/drivers/serial/serial_meson.c#L44
Signed-off-by: Amit Singh Tomar <amittomer25@gmail.com>
---
Changes since v3:
* Change the commit message to include firmware names.
Changes since v2:
* Added the commit message that talks about
uart initialization.
* Added dummy early_uart_init function.
Changes since v1:
* Fixed coding style issue.
* Undone changes in early-printk.txt.
Changes since RFC:
* Replaced LDRH with LDR, with this there
is no scattered output on console now.
* Used tbnz instead of tst and b.ne.
* Used AML_ prefix against register names.
---
xen/arch/arm/arm64/debug-meson.inc | 55 ++++++++++++++++++++++++++++++++++++++
1 file changed, 55 insertions(+)
create mode 100644 xen/arch/arm/arm64/debug-meson.inc
diff --git a/xen/arch/arm/arm64/debug-meson.inc b/xen/arch/arm/arm64/debug-meson.inc
new file mode 100644
index 0000000..e1a8fa8
--- /dev/null
+++ b/xen/arch/arm/arm64/debug-meson.inc
@@ -0,0 +1,55 @@
+/*
+ * xen/arch/arm/arm64/debug-meson.inc
+ *
+ * MESON specific debug code.
+ *
+ * Copyright (c) 2019, Amit Singh Tomar <amittomer25@gmail.com>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms and conditions of the GNU General Public
+ * License, version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#define AML_UART_WFIFO_REG 0x00
+#define AML_UART_STATUS_REG 0x0c
+
+#define AML_UART_TX_FIFO_FULL 21
+
+.macro early_uart_init xb, c
+/* Uart has already been initialized by Firmware, for instance by TF-A */
+.endm
+
+/*
+ * MESON UART wait UART to be ready to transmit
+ * xb: register which contains the UART base address
+ * c: scratch register
+ */
+.macro early_uart_ready xb c
+1:
+ ldr w\c, [\xb, #AML_UART_STATUS_REG] /* status register */
+ tbnz w\c, #AML_UART_TX_FIFO_FULL, 1b /* Check TXFIFO FULL bit */
+.endm
+
+/*
+ * MESON UART transmit character
+ * xb: register which contains the UART base address
+ * wt: register which contains the character to transmit
+ */
+.macro early_uart_transmit xb wt
+ str \wt, [\xb, #AML_UART_WFIFO_REG]
+.endm
+
+/*
+ * Local variables:
+ * mode: ASM
+ * indent-tabs-mode: nil
+ * End:
+ */
--
2.7.4
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Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-develHi, On 14/04/2019 18:50, Amit Singh Tomar wrote: > This patch adds earlyprintk support for Amlogic Meson SoC based > boards. > > ATF[1] and U-boot[2] already initialize the UART for us. So no need to do it again. > > Tested With: > http://wiki.friendlyarm.com/wiki/index.php/NanoPi_K2 > > [1]: https://github.com/ARM-software/arm-trusted-firmware/blob/master/drivers/meson/console/aarch64/meson_console.S#L92 > [2]: https://github.com/u-boot/u-boot/blob/master/drivers/serial/serial_meson.c#L44 > > Signed-off-by: Amit Singh Tomar <amittomer25@gmail.com> Acked-by: Julien Grall <julien.grall@arm.com> I have pushed to my branch next-4.13 for now. It will be merged once the commit moratorium is lifted. Cheers, > --- > Changes since v3: > > * Change the commit message to include firmware names. > > Changes since v2: > > * Added the commit message that talks about > uart initialization. > > * Added dummy early_uart_init function. > > Changes since v1: > > * Fixed coding style issue. > * Undone changes in early-printk.txt. > > Changes since RFC: > > * Replaced LDRH with LDR, with this there > is no scattered output on console now. > * Used tbnz instead of tst and b.ne. > * Used AML_ prefix against register names. > > --- > xen/arch/arm/arm64/debug-meson.inc | 55 ++++++++++++++++++++++++++++++++++++++ > 1 file changed, 55 insertions(+) > create mode 100644 xen/arch/arm/arm64/debug-meson.inc > > diff --git a/xen/arch/arm/arm64/debug-meson.inc b/xen/arch/arm/arm64/debug-meson.inc > new file mode 100644 > index 0000000..e1a8fa8 > --- /dev/null > +++ b/xen/arch/arm/arm64/debug-meson.inc > @@ -0,0 +1,55 @@ > +/* > + * xen/arch/arm/arm64/debug-meson.inc > + * > + * MESON specific debug code. > + * > + * Copyright (c) 2019, Amit Singh Tomar <amittomer25@gmail.com>. > + * > + * This program is free software; you can redistribute it and/or > + * modify it under the terms and conditions of the GNU General Public > + * License, version 2, as published by the Free Software Foundation. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + * General Public License for more details. > + * > + * You should have received a copy of the GNU General Public > + * License along with this program; If not, see <http://www.gnu.org/licenses/>. > + */ > + > +#define AML_UART_WFIFO_REG 0x00 > +#define AML_UART_STATUS_REG 0x0c > + > +#define AML_UART_TX_FIFO_FULL 21 > + > +.macro early_uart_init xb, c > +/* Uart has already been initialized by Firmware, for instance by TF-A */ > +.endm > + > +/* > + * MESON UART wait UART to be ready to transmit > + * xb: register which contains the UART base address > + * c: scratch register > + */ > +.macro early_uart_ready xb c > +1: > + ldr w\c, [\xb, #AML_UART_STATUS_REG] /* status register */ > + tbnz w\c, #AML_UART_TX_FIFO_FULL, 1b /* Check TXFIFO FULL bit */ > +.endm > + > +/* > + * MESON UART transmit character > + * xb: register which contains the UART base address > + * wt: register which contains the character to transmit > + */ > +.macro early_uart_transmit xb wt > + str \wt, [\xb, #AML_UART_WFIFO_REG] > +.endm > + > +/* > + * Local variables: > + * mode: ASM > + * indent-tabs-mode: nil > + * End: > + */ > -- Julien Grall _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
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