diff options
Diffstat (limited to 'src/lib')
| -rw-r--r-- | src/lib/Makefile.inc | 3 | ||||
| -rw-r--r-- | src/lib/ramdetect.c | 78 |
2 files changed, 81 insertions, 0 deletions
diff --git a/src/lib/Makefile.inc b/src/lib/Makefile.inc index 7492b162dc..9deb5bf377 100644 --- a/src/lib/Makefile.inc +++ b/src/lib/Makefile.inc @@ -65,6 +65,7 @@ verstage-$(CONFIG_CONSOLE_CBMEM) += cbmem_console.c verstage-$(CONFIG_GENERIC_UDELAY) += timer.c verstage-$(CONFIG_GENERIC_GPIO_LIB) += gpio.c +romstage-$(CONFIG_VENDOR_EMULATION) += ramdetect.c romstage-y += prog_loaders.c romstage-y += prog_ops.c romstage-y += memchr.c @@ -105,6 +106,7 @@ endif romstage-$(CONFIG_GENERIC_UDELAY) += timer.c +ramstage-$(CONFIG_VENDOR_EMULATION) += ramdetect.c ramstage-y += prog_loaders.c ramstage-y += prog_ops.c ramstage-y += hardwaremain.c @@ -155,6 +157,7 @@ ramstage-y += cbmem_common.c ramstage-y += imd_cbmem.c ramstage-y += imd.c +postcar-$(CONFIG_VENDOR_EMULATION) += ramdetect.c postcar-y += cbmem_common.c postcar-$(CONFIG_CONSOLE_CBMEM) += cbmem_console.c postcar-y += imd_cbmem.c diff --git a/src/lib/ramdetect.c b/src/lib/ramdetect.c new file mode 100644 index 0000000000..5416a580dd --- /dev/null +++ b/src/lib/ramdetect.c @@ -0,0 +1,78 @@ +/* + * This file is part of the coreboot project. + * + * 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; version 2 of the License. + * + * 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 <types.h> +#include <symbols.h> +#include <device/mmio.h> +#include <ramdetect.h> +#include <console/console.h> + +#define OVERLAP(a, b, s, e) ((b) > (s) && (a) < (e)) + +static int probe_mb(const uintptr_t dram_start, const uintptr_t size) +{ + uintptr_t addr = dram_start + (size * MiB) - sizeof(uint32_t); + static const uint32_t patterns[] = { + 0x55aa55aa, + 0x12345678 + }; + void *ptr = (void *) addr; + size_t i; + + /* Don't accidentally clober oneself. */ + if (OVERLAP(addr, addr + sizeof(uint32_t), (uintptr_t)_program, (uintptr_t) _eprogram)) + return 1; + + uint32_t old = read32(ptr); + for (i = 0; i < ARRAY_SIZE(patterns); i++) { + write32(ptr, patterns[i]); + if (read32(ptr) != patterns[i]) + break; + } + + write32(ptr, old); + return i == ARRAY_SIZE(patterns); +} + +/* - 20 as probe_size is in MiB, - 1 as i is signed */ +#define MAX_ADDRESSABLE_SPACE (sizeof(size_t) * 8 - 20 - 1) + +/* Probe an area if it's read/writable. */ +size_t probe_ramsize(const uintptr_t dram_start, const size_t probe_size) +{ + ssize_t i; + size_t msb = 0; + size_t discovered = 0; + + static size_t saved_result; + if (saved_result) + return saved_result; + + /* Find the MSB + 1. */ + size_t tmp = probe_size; + do { + msb++; + } while (tmp >>= 1); + + /* Limit search to accessible address space */ + msb = MIN(msb, MAX_ADDRESSABLE_SPACE); + + /* Compact binary search. */ + for (i = msb; i >= 0; i--) + if (probe_mb(dram_start, (discovered | (1ULL << i)))) + discovered |= (1ULL << i); + + saved_result = discovered; + printk(BIOS_DEBUG, "RAMDETECT: Found %zu MiB RAM\n", discovered); + return discovered; +} |