This patch adds earlyprintk support for i.MX8MQ SoC based boards. As with most of other debug code for other platforms, uart is initialized by bootloaders(for instance u-boot[1]).
[1]:https://github.com/u-boot/u-boot/blob/master/drivers/serial/serial_mxc.c#L141 Signed-off-by: Amit Singh Tomar <amittome...@gmail.com> --- xen/arch/arm/arm64/debug-imx8mq.inc | 54 +++++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) create mode 100644 xen/arch/arm/arm64/debug-imx8mq.inc diff --git a/xen/arch/arm/arm64/debug-imx8mq.inc b/xen/arch/arm/arm64/debug-imx8mq.inc new file mode 100644 index 0000000..ec331dc --- /dev/null +++ b/xen/arch/arm/arm64/debug-imx8mq.inc @@ -0,0 +1,54 @@ +/* + * xen/arch/arm/arm64/debug-imx8mq.inc + * + * IMX8MQ specific debug code. + * + * Copyright (c) 2019, 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 UTXD 0x40 +#define UTS 0xb4 +#define UTS_TXEMPTY 3<<1 + +.macro early_uart_init xb, c +/* Uart has already been initialized by bootloader Firmware, for instance by TF-A */ +.endm + +/* + * IMX8MQ 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, #UTS] /* UART Test Register */ + tbz w\c, #UTS_TXEMPTY, 1b /* Check TXEMPTY bit */ +.endm + +/* + * IMX8MQ 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, #UTXD] +.endm + +/* + * Local variables: + * mode: ASM + * indent-tabs-mode: nil + * End: + */ -- 2.7.4 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
