From ebe31c0a8ef7b59fd96171fe694339ce69ee24a6 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= Date: Thu, 16 Aug 2018 14:05:29 +0100 Subject: aspeed: add a max_ram_size property to the memory controller MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This will be used to construct a memory region beyond the RAM region to let firmwares scan the address space with load/store to guess how much RAM the SoC has. Signed-off-by: Cédric Le Goater Signed-off-by: Joel Stanley Tested-by: Cédric Le Goater Message-id: 20180807075757.7242-7-joel@jms.id.au Reviewed-by: Peter Maydell Signed-off-by: Peter Maydell --- hw/arm/aspeed.c | 31 +++++++++++++++++++++++++++++++ hw/arm/aspeed_soc.c | 2 ++ 2 files changed, 33 insertions(+) (limited to 'hw/arm') diff --git a/hw/arm/aspeed.c b/hw/arm/aspeed.c index bb9d33848d..bb9590f1ae 100644 --- a/hw/arm/aspeed.c +++ b/hw/arm/aspeed.c @@ -31,6 +31,7 @@ static struct arm_boot_info aspeed_board_binfo = { typedef struct AspeedBoardState { AspeedSoCState soc; MemoryRegion ram; + MemoryRegion max_ram; } AspeedBoardState; typedef struct AspeedBoardConfig { @@ -127,6 +128,27 @@ static const AspeedBoardConfig aspeed_boards[] = { }, }; +/* + * The max ram region is for firmwares that scan the address space + * with load/store to guess how much RAM the SoC has. + */ +static uint64_t max_ram_read(void *opaque, hwaddr offset, unsigned size) +{ + return 0; +} + +static void max_ram_write(void *opaque, hwaddr offset, uint64_t value, + unsigned size) +{ + /* Discard writes */ +} + +static const MemoryRegionOps max_ram_ops = { + .read = max_ram_read, + .write = max_ram_write, + .endianness = DEVICE_NATIVE_ENDIAN, +}; + #define FIRMWARE_ADDR 0x0 static void write_boot_rom(DriveInfo *dinfo, hwaddr addr, size_t rom_size, @@ -187,6 +209,7 @@ static void aspeed_board_init(MachineState *machine, AspeedBoardState *bmc; AspeedSoCClass *sc; DriveInfo *drive0 = drive_get(IF_MTD, 0, 0); + ram_addr_t max_ram_size; bmc = g_new0(AspeedBoardState, 1); object_initialize(&bmc->soc, (sizeof(bmc->soc)), cfg->soc_name); @@ -226,6 +249,14 @@ static void aspeed_board_init(MachineState *machine, object_property_add_const_link(OBJECT(&bmc->soc), "ram", OBJECT(&bmc->ram), &error_abort); + max_ram_size = object_property_get_uint(OBJECT(&bmc->soc), "max-ram-size", + &error_abort); + memory_region_init_io(&bmc->max_ram, NULL, &max_ram_ops, NULL, + "max_ram", max_ram_size - ram_size); + memory_region_add_subregion(get_system_memory(), + sc->info->sdram_base + ram_size, + &bmc->max_ram); + aspeed_board_init_flashes(&bmc->soc.fmc, cfg->fmc_model, &error_abort); aspeed_board_init_flashes(&bmc->soc.spi[0], cfg->spi_model, &error_abort); diff --git a/hw/arm/aspeed_soc.c b/hw/arm/aspeed_soc.c index e68911af0f..a27233d487 100644 --- a/hw/arm/aspeed_soc.c +++ b/hw/arm/aspeed_soc.c @@ -155,6 +155,8 @@ static void aspeed_soc_init(Object *obj) sc->info->silicon_rev); object_property_add_alias(obj, "ram-size", OBJECT(&s->sdmc), "ram-size", &error_abort); + object_property_add_alias(obj, "max-ram-size", OBJECT(&s->sdmc), + "max-ram-size", &error_abort); for (i = 0; i < sc->info->wdts_num; i++) { object_initialize(&s->wdt[i], sizeof(s->wdt[i]), TYPE_ASPEED_WDT); -- cgit v1.2.3