diff options
| -rw-r--r-- | drivers/coreboot/cbmem_console/aarch64/cbmem_console.S | 101 | ||||
| -rw-r--r-- | include/drivers/coreboot/cbmem_console.h | 27 | ||||
| -rw-r--r-- | lib/coreboot/coreboot.mk | 4 | ||||
| -rw-r--r-- | lib/coreboot/coreboot_table.c | 34 |
4 files changed, 166 insertions, 0 deletions
diff --git a/drivers/coreboot/cbmem_console/aarch64/cbmem_console.S b/drivers/coreboot/cbmem_console/aarch64/cbmem_console.S new file mode 100644 index 00000000..2fc06033 --- /dev/null +++ b/drivers/coreboot/cbmem_console/aarch64/cbmem_console.S @@ -0,0 +1,101 @@ +/* + * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved. + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +#include <asm_macros.S> +#include <cbmem_console.h> +#include <console_macros.S> + +/* + * This driver implements access to coreboot's in-memory console + * (CBMEM console). For the original implementation, see + * <coreboot>/src/lib/cbmem_console.c. + */ + + .globl console_cbmc_register + .globl console_cbmc_putc + .globl console_cbmc_flush + + /* ----------------------------------------------- + * int console_cbmc_register(console_cbmc_t *console, + * uintptr_t base) + * Registers a new CBMEM console instance. Reads + * the size field from the buffer header structure + * and stores it in our console_cbmc_t struct, so + * that we keep the size in secure memory where we + * can trust it. A malicious EL1 could manipulate + * the console buffer (including the header), so we + * must not trust its contents after boot. + * In: x0 - CBMEM console base address + * x1 - pointer to empty console_cbmc_t struct + * Out: x0 - 1 to indicate success + * Clobber list: x0, x1, x2, x7 + * ----------------------------------------------- + */ +func console_cbmc_register + str x0, [x1, #CONSOLE_T_CBMC_BASE] + ldr w2, [x0] + str w2, [x1, #CONSOLE_T_CBMC_SIZE] + mov x0, x1 + finish_console_register cbmc +endfunc console_cbmc_register + + /* ----------------------------------------------- + * int console_cbmc_puts(int c, console_cbmc_t *console) + * Writes a character to the CBMEM console buffer, + * including overflow handling of the cursor field. + * The character must be preserved in x0. + * In: x0 - character to be stored + * x1 - pointer to console_cbmc_t struct + * Clobber list: x1, x2, x16, x17 + * ----------------------------------------------- + */ +func console_cbmc_putc + ldr w2, [x1, #CONSOLE_T_CBMC_SIZE] + ldr x1, [x1, #CONSOLE_T_CBMC_BASE] + add x1, x1, #8 /* keep address of body in x1 */ + + ldr w16, [x1, #-4] /* load cursor (one u32 before body) */ + and w17, w16, #0xf0000000 /* keep flags part in w17 */ + and w16, w16, #0x0fffffff /* keep actual cursor part in w16 */ + + cmp w16, w2 /* sanity check that cursor < size */ + b.lo putc_within_bounds + mov w0, #-1 /* cursor >= size must be malicious */ + ret /* so return error, don't write char */ + +putc_within_bounds: + strb w0, [x1, w16, uxtw] /* body[cursor] = character */ + add w16, w16, #1 /* cursor++ */ + cmp w16, w2 /* if cursor < size... */ + b.lo putc_write_back /* ...skip overflow handling */ + + mov w16, #0 /* on overflow, set cursor back to 0 */ + orr w17, w17, #(1 << 31) /* and set overflow flag */ + +putc_write_back: + orr w16, w16, w17 /* merge cursor and flags back */ + str w16, [x1, #-4] /* write back cursor to memory */ + ret +endfunc console_cbmc_putc + + /* ----------------------------------------------- + * int console_cbmc_flush(console_cbmc_t *console) + * Flushes the CBMEM console by flushing the + * console buffer from the CPU's data cache. + * In: x0 - pointer to console_cbmc_t struct + * Out: x0 - 0 for success + * Clobber list: x0, x1, x2, x3, x5 + * ----------------------------------------------- + */ +func console_cbmc_flush + mov x5, x30 + ldr x1, [x0, #CONSOLE_T_CBMC_SIZE] + ldr x0, [x0, #CONSOLE_T_CBMC_BASE] + add x1, x1, #8 /* add size of console header */ + bl clean_dcache_range /* (clobbers x2 and x3) */ + mov x0, #0 + ret x5 +endfunc console_cbmc_flush diff --git a/include/drivers/coreboot/cbmem_console.h b/include/drivers/coreboot/cbmem_console.h new file mode 100644 index 00000000..4fca36f6 --- /dev/null +++ b/include/drivers/coreboot/cbmem_console.h @@ -0,0 +1,27 @@ +/* + * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved. + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +#ifndef __CBMEM_CONSOLE_H__ +#define __CBMEM_CONSOLE_H__ + +#include <console.h> + +#define CONSOLE_T_CBMC_BASE CONSOLE_T_DRVDATA +#define CONSOLE_T_CBMC_SIZE (CONSOLE_T_DRVDATA + REGSZ) + +#ifndef __ASSEMBLER__ + +typedef struct { + console_t console; + uintptr_t base; + uint32_t size; +} console_cbmc_t; + +int console_cbmc_register(uintptr_t base, console_cbmc_t *console); + +#endif /* __ASSEMBLER__ */ + +#endif /* __CBMEM_CONSOLE_H__ */ diff --git a/lib/coreboot/coreboot.mk b/lib/coreboot/coreboot.mk index 0cd103f2..bbaa3329 100644 --- a/lib/coreboot/coreboot.mk +++ b/lib/coreboot/coreboot.mk @@ -17,4 +17,8 @@ endif BL31_SOURCES += $(addprefix lib/coreboot/, \ coreboot_table.c) +BL31_SOURCES += drivers/coreboot/cbmem_console/${ARCH}/cbmem_console.S + +INCLUDES += -Iinclude/drivers/coreboot + endif # COREBOOT diff --git a/lib/coreboot/coreboot_table.c b/lib/coreboot/coreboot_table.c index 76e5d3b7..64f8879e 100644 --- a/lib/coreboot/coreboot_table.c +++ b/lib/coreboot/coreboot_table.c @@ -4,10 +4,13 @@ * SPDX-License-Identifier: BSD-3-Clause */ +#include <assert.h> +#include <cbmem_console.h> #include <coreboot.h> #include <debug.h> #include <mmio.h> #include <string.h> +#include <xlat_tables_v2.h> /* * Structures describing coreboot's in-memory descriptor tables. See @@ -26,6 +29,7 @@ typedef struct { typedef enum { CB_TAG_SERIAL = 0xf, + CB_TAG_CBMEM_CONSOLE = 0x17, } cb_tag_t; typedef struct { @@ -33,6 +37,7 @@ typedef struct { uint32_t size; union { coreboot_serial_t serial; + uint64_t uint64; }; } cb_entry_t; @@ -53,6 +58,32 @@ static uint32_t read_le32(uint32_t *p) mmio_read_8(addr + 2) << 16 | mmio_read_8(addr + 3) << 24; } +static uint64_t read_le64(uint64_t *p) +{ + return read_le32((void *)p) | (uint64_t)read_le32((void *)p + 4) << 32; +} + +static void expand_and_mmap(uintptr_t baseaddr, size_t size) +{ + uintptr_t pageaddr = round_down(baseaddr, PAGE_SIZE); + size_t expanded = round_up(baseaddr - pageaddr + size, PAGE_SIZE); + mmap_add_region(pageaddr, pageaddr, expanded, + MT_MEMORY | MT_RW | MT_NS | MT_EXECUTE_NEVER); +} + +static void setup_cbmem_console(uintptr_t baseaddr) +{ + static console_cbmc_t console; + assert(!console.base); /* should only have one CBMEM console */ + + /* CBMEM console structure stores its size in first header field. */ + uint32_t size = *(uint32_t *)baseaddr; + expand_and_mmap(baseaddr, size); + console_cbmc_register(baseaddr, &console); + console_set_scope(&console.console, CONSOLE_FLAG_BOOT | + CONSOLE_FLAG_RUNTIME | + CONSOLE_FLAG_CRASH); +} void coreboot_table_setup(void *base) { @@ -79,6 +110,9 @@ void coreboot_table_setup(void *base) memcpy(&coreboot_serial, &entry->serial, sizeof(coreboot_serial)); break; + case CB_TAG_CBMEM_CONSOLE: + setup_cbmem_console(read_le64(&entry->uint64)); + break; default: /* There are many tags TF doesn't need to care about. */ break; |