The read/write operations done by FEL are not suitable for accessing hardware registers. For example, trying to read a SID value using the "read" or "hexdump" commands results in the following:
$ sunxi-fel hexdump 0x01c23800 4 01c23800: 87 00 00 00 __ __ __ __ __ __ __ __ __ __ __ __ Apparently, FEL tries to read data one byte at a time and this does not always work correctly. Introducing new commands to explicitly do 32-bit reads and writes helps: $ sunxi-fel readl 0x01c23800 0x16254187 Signed-off-by: Siarhei Siamashka <[email protected]> --- fel.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) diff --git a/fel.c b/fel.c index a597e11..d3d6f62 100644 --- a/fel.c +++ b/fel.c @@ -654,6 +654,38 @@ void aw_write_arm_cp_reg(libusb_device_handle *usb, soc_sram_info *sram_info, aw_fel_execute(usb, sram_info->scratch_addr); } +uint32_t aw_fel_readl(libusb_device_handle *usb, uint32_t addr) +{ + soc_sram_info *sram_info = aw_fel_get_sram_info(usb); + uint32_t val = 0; + uint32_t arm_code[] = { + htole32(0xe59f0008), /* ldr r0, [pc, #8] */ + htole32(0xe5900000), /* ldr r0, [r0] */ + htole32(0xe58f0000), /* str r0, [pc] */ + htole32(0xe12fff1e), /* bx lr */ + htole32(addr) + }; + aw_fel_write(usb, arm_code, sram_info->scratch_addr, sizeof(arm_code)); + aw_fel_execute(usb, sram_info->scratch_addr); + aw_fel_read(usb, sram_info->scratch_addr + 16, &val, sizeof(val)); + return le32toh(val); +} + +void aw_fel_writel(libusb_device_handle *usb, uint32_t addr, uint32_t val) +{ + soc_sram_info *sram_info = aw_fel_get_sram_info(usb); + uint32_t arm_code[] = { + htole32(0xe59f0008), /* ldr r0, [pc, #8] */ + htole32(0xe59f1008), /* ldr r1, [pc, #8] */ + htole32(0xe5801000), /* str r1, [r0] */ + htole32(0xe12fff1e), /* bx lr */ + htole32(addr), + htole32(val) + }; + aw_fel_write(usb, arm_code, sram_info->scratch_addr, sizeof(arm_code)); + aw_fel_execute(usb, sram_info->scratch_addr); +} + void aw_enable_l2_cache(libusb_device_handle *usb, soc_sram_info *sram_info) { uint32_t arm_code[] = { @@ -1314,6 +1346,8 @@ int main(int argc, char **argv) " hex[dump] address length Dumps memory region in hex\n" " dump address length Binary memory dump\n" " exe[cute] address Call function address\n" + " readl address Read 32-bit value from device memory\n" + " writel address value Write 32-bit value to device memory\n" " read address length file Write memory contents into file\n" " write address file Store file contents into memory\n" " write-with-progress addr file \"write\" with progress bar\n" @@ -1380,6 +1414,16 @@ int main(int argc, char **argv) } else if (strncmp(argv[1], "dump", 4) == 0 && argc > 3) { aw_fel_dump(handle, strtoul(argv[2], NULL, 0), strtoul(argv[3], NULL, 0)); skip = 3; + } else if (strcmp(argv[1], "readl") == 0 && argc > 2) { + uint32_t addr = strtoul(argv[2], NULL, 0); + uint32_t val = aw_fel_readl(handle, addr); + printf("0x%08x\n", val); + skip = 2; + } else if (strcmp(argv[1], "writel") == 0 && argc > 2) { + uint32_t addr = strtoul(argv[2], NULL, 0); + uint32_t val = strtoul(argv[3], NULL, 0); + aw_fel_writel(handle, addr, val); + skip = 3; } else if (strncmp(argv[1], "exe", 3) == 0 && argc > 2) { aw_fel_execute(handle, strtoul(argv[2], NULL, 0)); skip=3; -- 2.4.10 -- You received this message because you are subscribed to the Google Groups "linux-sunxi" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
