lpcspifi: setup a valid stack pointer before calling ROM code using stack

The spifi_init_code blob is calling the spifi_init() function from the ROM.
This ROM function is making use of the stack. So if the stack pointer is
invalid, trying to execute this code leads to a double fault and the
target_run_algorithm() call return with an error.
This patch simply ensure that the stack pointer is properly setup before
calling the spifi_init() ROM function.

Change-Id: I42a2163cfc2c6dfe5ada97ae8eb2bb6d2e283ff7
Signed-off-by: Aurelien Jacobs <aurel@gnuage.org>
Reviewed-on: http://openocd.zylin.com/1836
Tested-by: jenkins
Reviewed-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>

diff --git a/src/flash/nor/lpcspifi.c b/src/flash/nor/lpcspifi.c
index 2f4c6010e1da3fc2a3707dc85d6c8c7fbe59f555..7355c30a9ceacc627e9a6d80e1d7d253311cc26a 100644 (file)
--- a/src/flash/nor/lpcspifi.c
+++ b/src/flash/nor/lpcspifi.c
@@ -44,6 +44,10 @@
 #define SSP_PROBE_TIMEOUT (100)
 #define SSP_MAX_TIMEOUT  (3000)
 
+/* Size of the stack to alloc in the working area for the execution of
+ * the ROM spifi_init() function */
+#define SPIFI_INIT_STACK_SIZE  512
+
 struct lpcspifi_flash_bank {
        int probed;
        uint32_t ssp_base;
@@ -151,7 +155,7 @@ static int lpcspifi_set_hw_mode(struct flash_bank *bank)
        uint32_t ssp_base = lpcspifi_info->ssp_base;
        struct armv7m_algorithm armv7m_info;
        struct working_area *spifi_init_algorithm;
-       struct reg_param reg_params[1];
+       struct reg_param reg_params[2];
        int retval = ERROR_OK;
 
        LOG_DEBUG("Uninitializing LPC43xx SSP");
@@ -187,13 +191,13 @@ static int lpcspifi_set_hw_mode(struct flash_bank *bank)
 
        LOG_DEBUG("Allocating working area for SPIFI init algorithm");
        /* Get memory for spifi initialization algorithm */
-       retval = target_alloc_working_area(target, sizeof(spifi_init_code),
-               &spifi_init_algorithm);
+       retval = target_alloc_working_area(target, sizeof(spifi_init_code)
+               + SPIFI_INIT_STACK_SIZE, &spifi_init_algorithm);
        if (retval != ERROR_OK) {
                LOG_ERROR("Insufficient working area to initialize SPIFI "\
                        "module. You must allocate at least %zdB of working "\
                        "area in order to use this driver.",
-                       sizeof(spifi_init_code)
+                       sizeof(spifi_init_code) + SPIFI_INIT_STACK_SIZE
                );
 
                return retval;
@@ -214,6 +218,8 @@ static int lpcspifi_set_hw_mode(struct flash_bank *bank)
        }
 
        init_reg_param(&reg_params[0], "r0", 32, PARAM_OUT);            /* spifi clk speed */
+       /* the spifi_init() rom API makes use of the stack */
+       init_reg_param(&reg_params[1], "sp", 32, PARAM_OUT);
 
        /* For now, the algorithm will set up the SPIFI module
         * @ the IRC clock speed. In the future, it could be made
@@ -221,10 +227,13 @@ static int lpcspifi_set_hw_mode(struct flash_bank *bank)
         * already configured them in order to speed up memory-
         * mapped reads. */
        buf_set_u32(reg_params[0].value, 0, 32, 12);
+       /* valid stack pointer */
+       buf_set_u32(reg_params[1].value, 0, 32, (spifi_init_algorithm->address +
+               sizeof(spifi_init_code) + SPIFI_INIT_STACK_SIZE) & ~7UL);
 
        /* Run the algorithm */
        LOG_DEBUG("Running SPIFI init algorithm");
-       retval = target_run_algorithm(target, 0 , NULL, 1, reg_params,
+       retval = target_run_algorithm(target, 0 , NULL, 2, reg_params,
                spifi_init_algorithm->address,
                spifi_init_algorithm->address + sizeof(spifi_init_code) - 2,
                1000, &armv7m_info);
@@ -235,6 +244,7 @@ static int lpcspifi_set_hw_mode(struct flash_bank *bank)
        target_free_working_area(target, spifi_init_algorithm);
 
        destroy_reg_param(&reg_params[0]);
+       destroy_reg_param(&reg_params[1]);
 
        return retval;
 }