diff options
Diffstat (limited to 'drivers/uart.cc')
| -rw-r--r-- | drivers/uart.cc | 181 |
1 files changed, 0 insertions, 181 deletions
diff --git a/drivers/uart.cc b/drivers/uart.cc deleted file mode 100644 index 467b496..0000000 --- a/drivers/uart.cc +++ /dev/null @@ -1,181 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-or-later */ -/* Copyright (C) 2026 Richard Qin */ - -/* - * uart.cc — 16550a UART driver + console registry - * - * Two roles: - * 1. Early console: early_putc() for pre-init output (panic, kprintf) - * 2. Runtime console: struct console registered with register_console(). - * klog/printk route through console_write_all() → uart_console_write(). - * - * The console registry is a simple linked list of struct console. - * console_write_all() iterates the list and calls each console's write(). - * If no console is registered, it falls back to early_putc(). - * - * Reference: Linux kernel/printk/printk.c, drivers/tty/serial/8250/ - */ - -#include <lume/console.h> -#include <lume/fdt.h> -#include <lume/vmm.h> -#include <lume/addr.h> -#include <arch/config.h> - -/* ================================================================== */ -/* UART state */ -/* ================================================================== */ - -static uint64 g_uart_pa = 0; -static uint64 g_uart_size = 0; -static bool g_runtime_mapping_ready = false; -static bool g_mmu_enabled = false; - -/* ================================================================== */ -/* Early console (Phase 1) */ -/* ================================================================== */ - -extern "C" void console_set_mmu_enabled() { - g_mmu_enabled = true; -} - -extern "C" void early_putc(char c) { - if (!g_uart_pa) return; - - /* - * Before vmm_init() activates the final page table, UART MMIO is only - * reachable via the bootstrap fixed direct map from entry.S. - * After activation, switch to the runtime (possibly KASLR-slid) base. - */ - uint64 uart_va = 0; - if (g_runtime_mapping_ready) { - uart_va = pa_to_va(phys_addr(g_uart_pa)).raw; - } else if (!g_mmu_enabled) { - uart_va = g_uart_pa; - } else { - uart_va = boot_pa_to_va(phys_addr(g_uart_pa)).raw; - } - - volatile auto* uart = reinterpret_cast<volatile uint8*>(uart_va); - *uart = static_cast<uint8>(c); -} - -extern "C" void early_puts(const char* s) { - while (*s) early_putc(*s++); -} - -void console_early_init(uint64 fdt_paddr) { - uint64 pa = 0; - uint64 size = 0; - FdtManager::early_scan_uart(fdt_paddr, &pa, &size); - if (pa != 0) { - g_uart_pa = pa; - if (size != 0) g_uart_size = size; - } -} - -void console_init() { - /* - * Once vmm_init() activates the new page table, the 1GB identity map is dropped. - * The UART must be explicitly registered into the active page table. - */ - if (g_uart_pa != 0 && g_uart_size != 0) { - vmm_map_kernel_mmio(g_uart_pa, g_uart_size); - } -} - -void console_use_runtime_mapping() { - g_runtime_mapping_ready = true; -} - -/* ================================================================== */ -/* Console registry (Phase 2) — linked list of struct console */ -/* ================================================================== */ - -static list_node g_console_list; -static bool g_console_list_init = false; - -void register_console(console* con) -{ - if (!con) return; - - if (!g_console_list_init) { - g_console_list.init(); - g_console_list_init = true; - } - - con->flags |= CON_ENABLED; - con->list.init(); - - /* Insert at tail */ - list_add_tail(&con->list, &g_console_list); -} - -void unregister_console(console* con) -{ - if (!con) return; - - list_del_init(&con->list); - con->flags &= ~CON_ENABLED; -} - -bool console_drivers_registered() -{ - if (!g_console_list_init) return false; - return !list_empty(&g_console_list); -} - -void console_write_all(const char* s, int count) -{ - if (g_console_list_init && !list_empty(&g_console_list)) { - list_node* pos; - list_for_each(pos, &g_console_list) { - auto* con = container_of(pos, console, list); - if ((con->flags & CON_ENABLED) && con->write) { - con->write(con, s, static_cast<unsigned int>(count)); - } - } - } else { - /* Fallback: direct early_putc (pre-registration) */ - for (int i = 0; i < count; i++) { - early_putc(s[i]); - } - } -} - -/* ================================================================== */ -/* UART console driver */ -/* ================================================================== */ - -static void uart_console_write(console* /*con*/, const char* s, unsigned int count) -{ - for (unsigned int i = 0; i < count; i++) { - if (s[i] == '\n') { - early_putc('\r'); - } - early_putc(s[i]); - } -} - -/* - * uart_console must be initialized at RUNTIME, not with static - * aggregate initializers. Reason: KASLR self-relocation processes - * .rela.dyn entries for simple pointer variables, but may not cover - * function pointer fields inside static aggregate initializers. - * A static `{ .write = uart_console_write }` would store the - * pre-relocation address, causing a crash when called. - */ -static console uart_console; - -void uart_register_console() -{ - uart_console.name = "ttyS"; - uart_console.write = uart_console_write; - uart_console.setup = nullptr; - uart_console.flags = CON_ENABLED | CON_BOOT; - uart_console.index = 0; - uart_console.data = nullptr; - uart_console.list.init(); - register_console(&uart_console); -} - |