Commit 661bfc80 authored by Jan Kiszka's avatar Jan Kiszka Committed by Aurelien Jarno
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pflash: Restore & fix lazy ROMD switching 



Commit 5145b3d1 revealed a bug in the lazy ROMD switch-back logic, but
resolved it by breaking that feature. This approach addresses the issue
by switching back to ROMD after a certain amount of read accesses
without further unlock sequences.

Signed-off-by: default avatarJan Kiszka <jan.kiszka@web.de>
Signed-off-by: default avatarAurelien Jarno <aurelien@aurel32.net>
parent 70afb8ff

hw/pflash_cfi02.c

+8 −4
Original line number Diff line number Diff line
@@ -50,6 +50,8 @@ do { \ 
#define DPRINTF(fmt, ...) do { } while (0)

#endif



#define PFLASH_LAZY_ROMD_THRESHOLD 42



struct pflash_t {

    BlockDriverState *bs;

    target_phys_addr_t base;
@@ -70,6 +72,7 @@ struct pflash_t { 
    ram_addr_t off;

    int fl_mem;

    int rom_mode;

    int read_counter; /* used for lazy switch-back to rom mode */

    void *storage;

};
@@ -112,9 +115,9 @@ static uint32_t pflash_read (pflash_t *pfl, target_phys_addr_t offset, 


    DPRINTF("%s: offset " TARGET_FMT_plx "\n", __func__, offset);

    ret = -1;

    if (!pfl->rom_mode) {

        /* Lazy reset of to ROMD mode */

        if (pfl->wcycle == 0)

    /* Lazy reset to ROMD mode after a certain amount of read accesses */

    if (!pfl->rom_mode && pfl->wcycle == 0 &&

        ++pfl->read_counter > PFLASH_LAZY_ROMD_THRESHOLD) {

        pflash_register_memory(pfl, 1);

    }

    offset &= pfl->chip_len - 1;
@@ -254,6 +257,7 @@ static void pflash_write (pflash_t *pfl, target_phys_addr_t offset, 
        /* Set the device in I/O access mode if required */

        if (pfl->rom_mode)

            pflash_register_memory(pfl, 0);

        pfl->read_counter = 0;

        /* We're in read mode */

    check_unlock0:

        if (boff == 0x55 && cmd == 0x98) {