lby/lk
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

[dev][pl011] track if the uart has been initialized

Browse Source 
Dont deref a bad pointer if the uart is uninitialized. This helps if a
system tries to print too early in the boot process.
This commit is contained in:
Travis Geiselbrecht
2025-10-05 15:43:03 -07:00
parent 664bb17afa
commit 6f89579856
2 changed files with 51 additions and 34 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
dev/uart/pl011/include/dev/uart/pl011.h
View File

@@ -12,7 +12,7 @@
// Set this flag if the UART is a debug UART, which routes input
// directly into the console buffer if present.
#define PL011_FLAG_DEBUG_UART (1u<<0)
#define PL011_FLAG_DEBUG_UART (1u << 0)
struct pl011_config {
uintptr_t base;

83
dev/uart/pl011/uart.c
View File

@@ -5,57 +5,57 @@
* license that can be found in the LICENSE file or at
* https://opensource.org/licenses/MIT
*/
#include "include/dev/uart/pl011.h"
#include "dev/uart/pl011.h"
#include <assert.h>
#include <lk/trace.h>
#include <lib/cbuf.h>
#include <lib/io.h>
#include <dev/uart.h>
#include <kernel/thread.h>
#include <lib/cbuf.h>
#include <lib/io.h>
#include <lk/trace.h>
#include <platform/interrupts.h>
// PL011 UART driver
// PL011 registers
enum pl011_regs {
UART_DR = 0x00,
UART_RSR = 0x04,
UART_TFR = 0x18,
UART_ILPR = 0x20,
UART_IBRD = 0x24,
UART_FBRD = 0x28,
UART_LCRH = 0x2c,
UART_CR = 0x30,
UART_IFLS = 0x34,
UART_IMSC = 0x38,
UART_TRIS = 0x3c,
UART_TMIS = 0x40,
UART_ICR = 0x44,
UART_DR = 0x00,
UART_RSR = 0x04,
UART_TFR = 0x18,
UART_ILPR = 0x20,
UART_IBRD = 0x24,
UART_FBRD = 0x28,
UART_LCRH = 0x2c,
UART_CR = 0x30,
UART_IFLS = 0x34,
UART_IMSC = 0x38,
UART_TRIS = 0x3c,
UART_TMIS = 0x40,
UART_ICR = 0x44,
UART_DMACR = 0x48
};
// Control register bits that are used in the driver
#define UART_TFR_RXFE (1<<4)
#define UART_TFR_TXFF (1<<5)
#define UART_TFR_RXFF (1<<6)
#define UART_TFR_TXFE (1<<7)
#define UART_TFR_RXFE (1 << 4)
#define UART_TFR_TXFF (1 << 5)
#define UART_TFR_RXFF (1 << 6)
#define UART_TFR_TXFE (1 << 7)
#define UART_IMSC_RXIM (1<<4)
#define UART_IMSC_RXIM (1 << 4)
#define UART_TMIS_RXMIS (1<<4)
#define UART_TMIS_RXMIS (1 << 4)
#define UART_CR_UARTEN (1<<0)
#define UART_CR_TXEN (1<<8)
#define UART_CR_RXEN (1<<9)
#define UART_CR_UARTEN (1 << 0)
#define UART_CR_TXEN (1 << 8)
#define UART_CR_RXEN (1 << 9)
// TODO: have these be configurable
#define RXBUF_SIZE 32
#define NUM_UART 1
#define NUM_UART 1
struct pl011_struct {
bool initialized;
struct pl011_config config;
cbuf_t uart_rx_buf;
};
@@ -150,22 +150,32 @@ void pl011_init_early(int port, const struct pl011_config *config) {
// TODO: validate config
uart[port].config = *config;
uart[port].initialized = true;
write_uart_reg(uart[port].config.base, UART_CR, UART_CR_TXEN | UART_CR_UARTEN); // tx_enable, uarten
}
int uart_putc(int port, char c) {
DEBUG_ASSERT(port < NUM_UART);
if (uart[port].initialized == false) {
return -1;
}
uintptr_t base = uart_to_ptr(port);
/* spin while fifo is full */
while (read_uart_reg(base, UART_TFR) & UART_TFR_TXFF)
;
while (read_uart_reg(base, UART_TFR) & UART_TFR_TXFF);
write_uart_reg(base, UART_DR, c);
return 1;
}
int uart_getc(int port, bool wait) {
DEBUG_ASSERT(port < NUM_UART);
if (unlikely(uart[port].initialized == false)) {
return -1;
}
cbuf_t *rxbuf = &uart[port].uart_rx_buf;
char c;
@@ -179,17 +189,25 @@ int uart_getc(int port, bool wait) {
/* panic-time getc/putc */
int uart_pputc(int port, char c) {
DEBUG_ASSERT(port < NUM_UART);
if (unlikely(uart[port].initialized == false)) {
return -1;
}
uintptr_t base = uart_to_ptr(port);
/* spin while fifo is full */
while (read_uart_reg(base, UART_TFR) & UART_TFR_TXFF)
;
while (read_uart_reg(base, UART_TFR) & UART_TFR_TXFF);
write_uart_reg(base, UART_DR, c);
return 1;
}
int uart_pgetc(int port) {
DEBUG_ASSERT(port < NUM_UART);
if (unlikely(uart[port].initialized == false)) {
return -1;
}
uintptr_t base = uart_to_ptr(port);
if ((read_uart_reg(base, UART_TFR) & UART_TFR_RXFE) == 0) {
@@ -209,4 +227,3 @@ void uart_flush_rx(int port) {
// TODO collapse this into the early/regular init routines
void uart_init_port(int port, uint baud) {
}