From 890134dc8238cdd92507e831eed2418f7e720293 Mon Sep 17 00:00:00 2001 From: Stefan Lankes Date: Sun, 5 Mar 2017 18:48:51 +0100 Subject: [PATCH] simplify uart device - HermitCore uses on uart to send log messages to qemu - unidirectional communication => remove interrupt handler - remove mmio support for uart --- arch/x86/include/asm/uart.h | 6 -- arch/x86/kernel/uart.c | 150 ++---------------------------------- kernel/main.c | 1 - libkern/stdio.c | 2 +- 4 files changed, 8 insertions(+), 151 deletions(-) diff --git a/arch/x86/include/asm/uart.h b/arch/x86/include/asm/uart.h index 3514c30a2..f849fabeb 100644 --- a/arch/x86/include/asm/uart.h +++ b/arch/x86/include/asm/uart.h @@ -40,12 +40,6 @@ extern "C" { */ int uart_init(void); -/** @brief Initialize UART output without a device check - * - * @return Returns 0 on success - */ -int uart_early_init(char*); - /** @brief Simple string output on a serial device. * * If you want a new line you will have to "\\n". diff --git a/arch/x86/kernel/uart.c b/arch/x86/kernel/uart.c index 9dc9c1698..7a8a94044 100644 --- a/arch/x86/kernel/uart.c +++ b/arch/x86/kernel/uart.c @@ -97,40 +97,28 @@ #define UART_MCR_RTS 0x02 /* RTS complement */ #define UART_MCR_DTR 0x01 /* DTR complement */ -static uint8_t mmio = 0; static size_t iobase = 0; static inline unsigned char read_from_uart(uint32_t off) { uint8_t c = 0; - if (mmio) - c = *((const volatile unsigned char*) (iobase + off)); - else if (iobase) + if (iobase) c = inportb(iobase + off); return c; } -static void write_to_uart(uint32_t off, unsigned char c) +static inline void write_to_uart(uint32_t off, unsigned char c) { - if (mmio) - *((volatile unsigned char*) (iobase + off)) = c; - else if (iobase) + if (iobase) outportb(iobase + off, c); } - -/* Get a single character on a serial device */ -static unsigned char uart_getchar(void) -{ - return read_from_uart(UART_RX); -} - /* Puts a single character on a serial device */ int uart_putchar(unsigned char c) { - if (!iobase && !mmio) + if (!iobase) return 0; write_to_uart(UART_TX, c); @@ -143,7 +131,7 @@ int uart_puts(const char *text) { size_t i, len = strlen(text); - if (!iobase && !mmio) + if (!iobase) return 0; for (i = 0; i < len; i++) @@ -152,39 +140,6 @@ int uart_puts(const char *text) return len; } -/* Handles all UART's interrupt */ -static void uart_handler(struct state *s) -{ - unsigned char c = read_from_uart(UART_IIR); - - while (!(c & UART_IIR_NO_INT)) { - if (c & UART_IIR_RDI) { - c = uart_getchar(); - - //TODO: handle input messages - - goto out; - } - - if(c & UART_IIR_THRI) { - // acknowledge interrupt - c = read_from_uart(UART_IIR); - - goto out; - } - - if(c & UART_IIR_RLSI) { - // acknowledge interrupt - c = read_from_uart(UART_LSR); - - goto out; - } - -out: - c = read_from_uart(UART_IIR); - } -} - static int uart_config(void) { /* @@ -226,105 +181,14 @@ static int uart_config(void) extern const void kernel_start; -int uart_early_init(char* cmdline) -{ - if (is_uhyve()) - return 0; -#if 1 - // default value of our QEMU configuration - iobase = 0xc110; -#else - if (BUILTIN_EXPECT(!cmdline, 0)) - return -EINVAL; - - char* str = strstr(cmdline, "uart="); - if (!str) - return -EINVAL; - - if (strncmp(str, "uart=io:", 8) == 0) { - iobase = strtol(str+8, (char **)NULL, 16); - if (!iobase) - return -EINVAL; - mmio = 0; - } else if (strncmp(str, "uart=mmio:", 10) == 0) { - iobase = strtol(str+10, (char **)NULL, 16); - if (!iobase) - return -EINVAL; - if (iobase >= PAGE_MAP_ENTRIES*PAGE_SIZE) { - /* at this point we use the boot page table - * => IO address is not mapped - * => dirty hack, map device before the kernel - */ - int err; - size_t newaddr = ((size_t) &kernel_start - PAGE_SIZE); - - err = page_map_bootmap(newaddr & PAGE_MASK, iobase & PAGE_MASK, PG_GLOBAL | PG_ACCESSED | PG_DIRTY | PG_RW | PG_PCD); - if (BUILTIN_EXPECT(err, 0)) { - iobase = 0; - return err; - } - iobase = newaddr; - } - mmio = 1; - } -#endif - - // configure uart - return uart_config(); -} - int uart_init(void) { if (is_uhyve()) return 0; -#ifdef CONFIG_PCI - pci_info_t pci_info; - uint32_t bar = 0; - - // Searching for Intel's UART device - if (pci_get_device_info(0x8086, 0x0936, iobase, &pci_info) == 0) - goto Lsuccess; - // Searching for Qemu's UART device - if (pci_get_device_info(0x1b36, 0x0002, iobase, &pci_info) == 0) - goto Lsuccess; - // Searching for Qemu's 2x UART device (pci-serial-2x) - if (pci_get_device_info(0x1b36, 0x0003, iobase, &pci_info) == 0) - goto Lsuccess; - // Searching for Qemu's 4x UART device (pci-serial-4x) - if (pci_get_device_info(0x1b36, 0x0004, iobase, &pci_info) == 0) - goto Lsuccess; - - return -1; - -Lsuccess: - iobase = pci_info.base[bar]; - irq_install_handler(32+pci_info.irq, uart_handler); - if (pci_info.type[0]) { - mmio = 0; - LOG_INFO("UART uses io address 0x%x\n", iobase); - } else { - mmio = 1; - page_map(iobase & PAGE_MASK, iobase & PAGE_MASK, 1, PG_GLOBAL | PG_ACCESSED | PG_DIRTY | PG_RW | PG_PCD); - LOG_INFO("UART uses mmio address 0x%x\n", iobase); - vma_add(iobase, iobase + PAGE_SIZE, VMA_READ|VMA_WRITE); - } + // default value of our QEMU configuration + iobase = 0xc110; // configure uart return uart_config(); -#else - // per default we use COM1... - if (!iobase) - iobase = 0x3F8; - mmio = 0; - if ((iobase == 0x3F8) || (iobase == 0x3E8)) - irq_install_handler(32+4, uart_handler); - else if ((iobase == 0x2F8) || (iobase == 0x2E8)) - irq_install_handler(32+3, uart_handler); - else - return -EINVAL; - - // configure uart - return uart_config(); -#endif } diff --git a/kernel/main.c b/kernel/main.c index 2eda4d3a8..bbd6d00d9 100644 --- a/kernel/main.c +++ b/kernel/main.c @@ -132,7 +132,6 @@ static int hermit_init(void) multitasking_init(); memory_init(); signal_init(); - uart_init(); return 0; } diff --git a/libkern/stdio.c b/libkern/stdio.c index ed53c1885..0b1976589 100644 --- a/libkern/stdio.c +++ b/libkern/stdio.c @@ -45,7 +45,7 @@ spinlock_irqsave_t stdio_lock = SPINLOCK_IRQSAVE_INIT; int koutput_init(void) { if (is_single_kernel()) - uart_early_init(NULL); + uart_init(); return 0; }