/* * xen/arch/arm/arm32/debug-8250.inc * * 8250 specific debug code * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * 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. */ #include /* 8250 UART wait UART to be ready to transmit * rb: register which contains the UART base address * rc: scratch register */ .macro early_uart_ready rb rc 1: ldr \rc, [\rb, #(UART_LSR << EARLY_UART_REG_SHIFT)] /* Read LSR */ tst \rc, #UART_LSR_THRE /* Check Xmit holding register flag */ beq 1b /* Wait for the UART to be ready */ .endm /* 8250 UART transmit character * rb: register which contains the UART base address * rt: register which contains the character to transmit */ .macro early_uart_transmit rb rt str \rt, [\rb, #UART_THR] /* Write Transmit buffer */ .endm /* * Local variables: * mode: ASM * indent-tabs-mode: nil * End: */