Hi Amit, On 07/08/18 18:07, Amit Singh Tomar wrote:
Signed-off-by: Amit Singh Tomar <amittome...@gmail.com> --- docs/misc/arm/early-printk.txt | 1 + xen/arch/arm/Rules.mk | 1 + xen/arch/arm/arm64/debug-meson.inc | 50 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 52 insertions(+) create mode 100644 xen/arch/arm/arm64/debug-meson.incdiff --git a/docs/misc/arm/early-printk.txt b/docs/misc/arm/early-printk.txt index f765f59..2aa9528 100644 --- a/docs/misc/arm/early-printk.txt +++ b/docs/misc/arm/early-printk.txt @@ -41,6 +41,7 @@ the name of the machine: - juno: printk with pl011 on Juno platform - lager: printk with SCIF0 on Renesas R-Car H2 processors - midway: printk with the pl011 on Calxeda Midway processors + - meson: printk with the MESON for Amlogic S905 SoCs - mvebu: printk with the MVEBU for Marvell Armada 3700 SoCs - omap5432: printk with UART3 on TI OMAP5432 processors - rcar3: printk with SCIF2 on Renesas R-Car Gen3 processors diff --git a/xen/arch/arm/Rules.mk b/xen/arch/arm/Rules.mk index f264592..d4fabdc 100644 --- a/xen/arch/arm/Rules.mk +++ b/xen/arch/arm/Rules.mk @@ -36,6 +36,7 @@ EARLY_PRINTK_hikey960 := pl011,0xfff32000 EARLY_PRINTK_juno := pl011,0x7ff80000 EARLY_PRINTK_lager := scif,0xe6e60000 EARLY_PRINTK_midway := pl011,0xfff36000 +EARLY_PRINTK_meson := meson,0xc81004c0
I would prefer if no new alias are added. The same could be achieved with CONFIG_EARLY_PRINTK=meson,0xc81004c0.
This could be documented on the wiki. Cheers,
EARLY_PRINTK_mvebu := mvebu,0xd0012000 EARLY_PRINTK_omap5432 := 8250,0x48020000,2 EARLY_PRINTK_rcar3 := scif,0xe6e88000 diff --git a/xen/arch/arm/arm64/debug-meson.inc b/xen/arch/arm/arm64/debug-meson.inc new file mode 100644 index 0000000..d5507d3 --- /dev/null +++ b/xen/arch/arm/arm64/debug-meson.inc @@ -0,0 +1,50 @@ +/* + * xen/arch/arm/arm64/debug-meson.inc + * + * MESON specific debug code. + * + * Copyright (c) 2018, Amit Singh Tomar <amittome...@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 UART_STATUS_REG 0x0c +#define UART_TX_REG 0x00
I would prefer if we stick with the spec name. So UART_TX_REG should be renamed UART_WFIFO_REG.
Also, it might be worth considering to prefix them with AML_ so it is easy to find them on lookup.
+
Looking at the earlyconsole implementation in Linux, it seems that TX needs to be enabled first (see meson_uart_enable_tx_engine).
Is it now done in the firmware?
+/* + * 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: + ldrh w\c, [\xb, #UART_STATUS_REG] /* status register */ + tst w\c, #(1 << 21) /* Check TXFIFO FULL bit */
Please define 1 << 21 rather than hardcoding it.
+ b.ne 1b /* Wait for the UART to be ready */ +.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 + strb \wt, [\xb, #UART_TX_REG] +.endm + +/* + * Local variables: + * mode: ASM + * indent-tabs-mode: nil + * End: + */
Cheers, -- Julien Grall _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
